ORCID Profile
0000-0003-2975-0887
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Nanochemistry and Supramolecular Chemistry | Macromolecular and Materials Chemistry | Physical Organic Chemistry | Inorganic Chemistry not elsewhere classified | Transition metal chemistry | Supramolecular chemistry | Organic Chemistry | Catalysis and Mechanisms of Reactions | Macromolecular and materials chemistry
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Chemical Sciences | Rehabilitation of Degraded Fresh, Ground and Surface Water Environments | Hydrogen Storage |
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Publications
Triazole- and triazolium-containing porphyrin-cages for optical anion sensing
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2DT30124E
Abstract: Triazole and triazolium groups have been integrated into a zinc(II) metalloporphyrin-based structural framework to produce two porphyrin-cages for anion sensing applications. UV/visible spectroscopic titration investigations reveal both host systems exhibit strong anion binding affinities, with the positively-charged triazolium-porphyrin cage capable of colorimetric sensing halides, fluoride and chloride, and oxoanions in acetone-water solvent mixtures.
Factors Influencing Tetranuclear [2 × 2] Grid vs Dinuclear Side-by-Side Structures for Silver(I) Complexes of Pyridazine-Based Bis-Bidentate Ligands
Publisher: American Chemical Society (ACS)
Date: 17-11-2008
DOI: 10.1021/IC800959S
Abstract: Silver(I) complexes of five bis-bidentate Schiff-base ligands, derived from 3,6-diformylpyridazine and substituted anilines (2,4-dimethylaniline L ( o,p - Me ) 3,5-dichloroaniline L ( m,m - Cl ) 2-aminobiphenyl L ( o - Ph ) p-toluidine L ( p - Me ) 4-aminophenol L ( p - OH ) p-anisidine L ( p - OMe )), have been prepared. The ligands have a wide range of steric and electronic properties due to variation in the extent and nature of the substitution of the aniline rings. Four of the resulting complexes were structurally characterized by X-ray crystallography: three of the four, [Ag 2( L ( o,p - Me )) 2](BF 4) 2, [Ag 2( L ( m,m - Cl )) 2](BF 4) 2 and [Ag 2( L ( o - Ph )) 2](BF 4) 2 formed dinuclear side-by-side complexes, while [Ag 4( L ( p - Me )) 4](BF 4) 4 gave a tetranuclear [2 x 2] grid. The previously reported tetranuclear [2 x 2] grid [Ag 4( L ( p - OMe )) 4](BF 4) 4 was recrystallized in the presence of benzene to see if this would alter the architecture of this complex. It did not: the [2 x 2] grid architecture was retained despite the benzene molecules of solvation. Given the flexibility of silver(I) with regard to coordination geometry, the molecular structure of these complexes is influenced mostly by the ligand rather than the metal ion. In each case, the factors which influence the molecular architecture are presented and discussed. Substituent effects on the electrostatics of the intramolecular ligand-ligand pi-pi interactions (XED2.8) account for some of the differences observed in the structures.
Evidence for Halogen Bond Covalency in Acyclic and Interlocked Halogen-Bonding Receptor Anion Recognition
Publisher: American Chemical Society (ACS)
Date: 22-12-2014
DOI: 10.1021/JA511648D
Supramolecular chemistry of two new bis(1,2,3-triazolyl)pyridine macrocycles: metal complexation, self-assembly and anion binding
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2DT03985K
Abstract: Two new macrocycles containing bis(1,2,3-triazolyl)pyridine groups are reported. One forms nanotubes in the solid state, while the other binds anions and complexes transition metals.
Towards a self-assembled honeycomb structure via diaminotriptycene metal complexes
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3DT51330K
Abstract: We illustrate a new approach toward the synthesis of a porous supramolecular honeycomb based on triptycene. A coordination polymer has been prepared where the triptycene groups are linked through triptycenesemiquinonediimine platinum complexes, but the product is disordered rather than the intended honeycomb structure. A model platinum complex and its (15)N-labeled isotopomer have been prepared and characterized.
Anion-templated 2D frameworks from hexahydroxytriphenylene
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CE00297H
Halide selective anion recognition by an amide-triazolium axle containing [2]rotaxane
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4OB00801D
Abstract: A [2]rotaxane incorporating the novel 3-amido-phenyl-triazolium motif exhibits unusually high selectivity for halide anions over larger more basic oxoanions. Computational studies offer insight into this selectivity preference.
Synthesis and Structures of 3,5-disubstituted 1,2,4-triazole Head Units and Incorporation of 3,5-dibenzoyl-1,2,4-triazolate into New [2 + 2] Schiff-Base Macrocyclic Complexes
Publisher: Informa UK Limited
Date: 03-2007
Layered 2D Sheetlike Supramolecular Polymers Formed by O–H···Anion Hydrogen Bonds
Publisher: American Chemical Society (ACS)
Date: 17-02-2015
Mixed halide/oxoanion-templated frameworks
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CE00265C
Hydroxy Groups Enhance [2]Rotaxane Anion Binding Selectivity
Publisher: Wiley
Date: 05-04-2022
Abstract: We report the synthesis of two [2]rotaxanes containing an interlocked three dimensional binding cavity formed from a pyridinium bis(amide) axle component containing two phenol donors, and an isophthalamide based macrocycle. In the competitive solvent mixture 1 : 1 CDCl 3 : CD 3 OD, one of the receptors exhibits a much higher selectivity preference for chloride than an analogous rotaxane without the hydroxy groups. X‐ray crystal structures reveal the chloride anion guest encapsulated within the interlocked binding cavity, though not all of the hydrogen bond donors are utilised. Computational semi‐empirical simulations indicate that secondary intermolecular interactions occur between the axle hydroxy hydrogen bond donors and the [2]rotaxane macrocycle components, contributing to a more preorganised binding pocket, which may be responsible for the observed enhanced selectivity.
Enzyme Encapsulation in a Porous Hydrogen-Bonded Organic Framework
Publisher: American Chemical Society (ACS)
Date: 19-08-2019
DOI: 10.1021/JACS.9B06589
Abstract: Protection of biological assemblies is critical to applications in biotechnology, increasing the durability of enzymes in biocatalysis or potentially stabilizing biotherapeutics during transport and use. Here we show that a porous hydrogen-bonded organic framework (HOF) constructed from water-soluble tetra-amidinium (
Iron(II) Tris-[N4-substituted-3,5-di(2-pyridyl)-1,2,4-triazole] Complexes: Structural, Magnetic, NMR, and Density Functional Theory Studies
Publisher: American Chemical Society (ACS)
Date: 17-06-2009
DOI: 10.1021/IC900634T
Abstract: Eight mononuclear iron(II) complexes of N(4)-3,5-di(2-pyridyl)-1,2,4-triazole (Rdpt) ligands have been prepared and characterized. In all cases the iron(II)/ligand ratio used is 1:3, giving red complexes of the general formula [Fe(II)(Rdpt)(3)](BF(4))(2) x solvents, in 55-89% yield. The ligands differ only in the nature of the N(4)-substituent (amino, pyrrolyl, iso-butyl, methyl, phenyl, para-tolyl, 3,5-dichlorophenyl, and 4-pyridyl for ligands adpt, pldpt, ibdpt, medpt, phdpt, ptdpt, Cldpt, and pydpt, respectively) allowing substituent effects on the properties of the resulting iron(II) complexes to be probed. The low temperature crystal structures of seven of the complexes reveal low spin iron(II) environments. Packing analyses reveal anion-pi and acetonitrile-pi interactions involving the tetrafluoroborate counteranions and interstitial acetonitrile molecules, respectively. Both "pi-pockets" and "pi-sandwiches" are observed. Solid state magnetic susceptibility measurements (4-300 K) indicate the iron(II) is low spin (LS) in all complexes at all temperatures studied, except for [Fe(II)(pldpt)(3)](BF(4))(2) x 1 1/2 H(2)O which has the beginnings of spin crossover (SCO) at elevated temperatures. Downfield shifts and peak broadening observed in the variable temperature (1)H NMR studies indicate that in d(3)-nitromethane solution the LS [Fe(II)(Rdpt)(3)](2+) complexes are in equilibrium with a trace of a high spin (HS) species. (15)N NMR spectra (measured and calculated) of the ligands reveal that altering the N(4)-substituent changes the chemical shift of the N(1) triazole and pyridine nitrogen atoms, allowing probing of the relationship between ligand substituent and the nature of the coordinating nitrogen atoms.
Anion templated crystal engineering of halogen bonding tripodal tris(halopyridinium) compounds
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CE00241K
Abstract: Crystal engineering of halogen bonding tripodal receptors is found to be highly dependent on solvent and choice of anion.
A catenane host system containing integrated triazole C-H hydrogen bond donors for anion recognition
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC34210C
Abstract: A 3,5-bis(triazole)-pyridinium motif is integrated into a catenane structural framework via chloride anion templation. The catenane host system displays a high degree of selectivity for halide anions over dihydrogen phosphate.
Easily-prepared Hydroxy-containing Receptors Recognize Anions in Aqueous Media
Publisher: Wiley
Date: 12-02-2019
Abstract: Despite their ready availability, O-H groups have received relatively little attention as anion recognition motifs. Here, we report two simple hydroxy-containing anion receptors that are prepared in two facile steps followed by anion exchange, without the need for chromatographic purification at any stage. These receptors contain a pyridinium bis(amide) motif as well as hydroxyphenyl groups, and bind mono- and alent anions in 9:1 CD
Enhancement of Anion Recognition Exhibited by a Halogen-Bonding Rotaxane Host System
Publisher: American Chemical Society (ACS)
Date: 05-08-2010
DOI: 10.1021/JA105263Q
Abstract: We report the first use of solution-phase halogen bonding to control and facilitate the assembly of an interlocked structure through the bromide anion-templated formation of a rotaxane based upon an iodotriazolium axle. The incorporation of a halogen atom into the rotaxane host cavity dramatically improves the anion-recognition capabilities of the interlocked receptor, giving unusual iodide selectivity in a competitive aqueous medium.
Towards Langmuir–Blodgett films of magnetically interesting materials: solution equilibria in amphiphilic iron(ii) complexes of a triazole-containing ligand
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B923923E
Abstract: As a first step towards hiphilic spin crossover (SCO) systems where the hydrophobic part of the system is introduced by a non-coordinating anion (i.e. where no modification of the ligands to introduce hydrophobic substituents is required), [Fe(II)(OH(2))(2)(C(16)SO(3))(2)] and [Co(II)(OH(2))(2)(C(16)SO(3))(2)] have been prepared and reacted with the triazole-containing ligands adpt and pldpt (C(16)SO(3) = hexadecanesulfonate anion, adpt = 4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole, pldpt = 4-pyrrolyl-3,5-bis(2-pyridyl)-1,2,4-triazole). In the solid state, two HS complexes of the form [Fe(II)(Rdpt)(2)(C(16)SO(3))(2)] and two of the form [Co(II)(Rdpt)(2)(CH(3)OH)(2)](C(16)SO(3))(2) are obtained, even when a six-fold excess of ligand is used (Rdpt = adpt or pldpt). In solution, the cobalt complexes remain in this form as evidenced by colour, Visible/NIR and IR spectroscopy. For the iron complexes, there is an equilibrium in solution between the neutral high-spin form of the complex [Fe(II)(Rdpt)(2)(C(16)SO(3))(2)] and the dicationic low-spin tris form [Fe(II)(Rdpt)(3)](C(16)SO(3))(2). Polar solvents favour the dicationic form, while less polar solvents favour the neutral form (as evidenced by solution colour and solution IR spectroscopy). Visible/NIR spectroscopy and Evans' method NMR spectroscopy show the equilibrium can be shifted towards the [Fe(II)(Rdpt)(3)](C(16)SO(3))(2) form by adding additional ligand to the solution. The X-ray crystal structures of [Fe(II)(adpt)(2)(C(16)SO(3))(2)] and [Co(II)(adpt)(2)(CH(3)OH)(2)](C(16)SO(3))(2).1.33CH(3)OH are presented. [Fe(II)(adpt)(2)(C(16)SO(3))(2)] has a 2D bilayer structure with alternating layers of polar Fe(adpt)(2) centres, and hydrophobic alkyl chains. The complex cations in [Co(II)(adpt)(2)(CH(3)OH)(2)](C(16)SO(3))(2).1.33CH(3)OH form 1-D columns in the solid state. The capacity of the hiphilic complexes [Fe(II)(pldpt)(2)(C(16)SO(3))(2)] and [Fe(II)(adpt)(2)(C(16)SO(3))(2)] to self-assemble has been probed at the air-water interface using Langmuir techniques. The pertinent pressure-area isotherms reveal only a low tendency of the complexes to form films.
Recognition and applications of anion–anion dimers based on anti-electrostatic hydrogen bonds (AEHBs)
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CS00486C
Abstract: Contrary to expectations, protic hydroxyanions show a surprisingly reliable facility to dimerize or oligomerize together by hydrogen bonding.
Bis-triazolium containing macrocycles, pseudorotaxanes and interlocked structures for anion recognition
Publisher: Royal Society of Chemistry (RSC)
Date: 26-02-2014
DOI: 10.1039/C4RA00615A
Towards hydrogen and halogen bonded frameworks based on 3,5-bis(triazolyl)pyridinium motifs
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CE00273F
Abstract: Construction of supramolecular assemblies using hydrogen and halogen bonding between anions and the 3,5-bis(triazolyl)pyridinium motif was investigated.
A ferrocene redox-active triazolium macrocycle that binds and senses chloride
Publisher: Beilstein Institut
Date: 13-02-2012
DOI: 10.3762/BJOC.8.25
Abstract: A ferrocene bis(triazole) macrocycle was synthesised in good yield by the Eglinton coupling of an acyclic bis(alkyne) precursor and characterised in the solid state by X-ray crystallography. Alkylation gives the corresponding triazolium macrocycle, which binds chloride and benzoate strongly in CD 3 CN solution through favourable charge-assisted C–H···anion interactions, as evidenced by 1 H NMR titration experiments. Preliminary electrochemical studies reveal that the redox-active macrocycle is capable of sensing chloride in CH 3 CN solution.
Hydrogen bond-Driven Self–Assembly between Amidinium Cations and Carboxylate Anions: A Combined Molecular Dynamics, NMR Spectroscopy, and Single Crystal X-ray Diffraction Study
Publisher: Wiley
Date: 23-05-2017
Abstract: A combination of molecular dynamics (MD), NMR spectroscopy, and single crystal X-ray diffraction (SCXRD) techniques was used to probe the self-assembly of para- and meta-bis(amidinium) compounds with para-, meta-, and ortho-dicarboxylates. Good concordance was observed between the MD and experimental results. In DMSO solution, the systems form several rapidly exchanging assemblies, in part because a range of hydrogen bonding interactions is possible between the amidinium and carboxylate moieties. Upon crystallization, the majority of the systems form 1D supramolecular polymers, which are held together by short N-H⋅⋅⋅O hydrogen bonds.
Metal acetates form diverse polynuclear complexes with 4-amino-3,5-di(2-pyridyl)-1,2,4-triazole (adpt)
Publisher: Informa UK Limited
Date: 18-06-2013
A Halogen-Bonding Catenane for Anion Recognition and Sensing
Publisher: Wiley
Date: 16-01-2012
What’s in an Atom? a Comparison of Carbon and Silicon-Centered Amidinium···carboxylate Frameworks
Publisher: American Chemical Society (ACS)
Date: 19-08-2020
DOI: 10.26434/CHEMRXIV.12812000.V1
Abstract: Despite their apparent similarity, framework materials based on tetraphenylmethane and tetraphenylsilane building blocks often have quite different structures and topologies. Herein, we describe a new silicon tetraamidinium compound and use it to prepare crystalline hydrogen bonded frameworks with carboxylate anions in water. The silicon-containing frameworks are compared with those prepared from the analogous carbon tetraamidinium: when biphenyldicarboxylate or tetrakis(4-carboxyphenyl)methane anions were used similar channel-containing networks are observed for both the silicon and carbon tetraamidinium. When terephthalate or bicarbonate anions were used, different products form. Insights into possible reasons for the different products are provided by a survey of the Cambridge Structural Database and quantum chemical calculations, both of which indicate that, contrary to expectations, tetraphenylsilane derivatives have less geometrical flexibility than tetraphenylmethane derivatives, i.e. they are less able to distort away from ideal tetrahedral bond angles.
Observation of strong halogen bonds in the solid state structures of bis-haloimidazolium macrocycles
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CE41944D
Balancing on a Knife’s Edge: Studies on the Synthesis of Pillar[6]arene Derivatives
Publisher: American Chemical Society (ACS)
Date: 20-06-2023
Anion Templated Supramolecular Structures Assembled using 1,2,3‐Triazole and Triazolium motifs
Publisher: Wiley
Date: 12-02-2021
Open Pentiptycene Networks Assembled through Charge-Assisted Hydrogen Bonds
Publisher: American Chemical Society (ACS)
Date: 24-07-2019
Halogen- and hydrogen-bonding triazole-functionalised porphyrin-based receptors for anion recognition
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3DT52093E
Abstract: Iodotriazole and triazole anion recognition groups have been integrated into a picket-fence zinc(ii)-metalloporphyrin scaffold to produce receptors for anion recognition and sensing applications. (1)H NMR and UV/visible spectroscopic investigations reveal both host systems exhibit strong anion binding affinities in a range of solvent media. Importantly, the halogen-bonding iodotriazole-containing porphyrin-based host displays halide binding affinities substantially larger than the protic-functionalised analogue concomitant with a reduced strength of oxoanion complexation.
Cation-induced molecular motion of spring-like [2]catenanes
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1SC00034A
Effect of N-4-Substituent Choice on Spin Crossover in Dinuclear Iron(II) Complexes of Bis-Terdentate 1,2,4-Triazole-Based Ligands
Publisher: American Chemical Society (ACS)
Date: 20-09-2013
DOI: 10.1021/IC4014416
Abstract: Seven new dinuclear iron(II) complexes of the general formula [Fe(II)2(PMRT)2](BF4)4·solvent, where PMRT is a 4-substituted-3,5-bis{[(2-pyridylmethyl)-amino]methyl}-4H-1,2,4-triazole, have been prepared in order to investigate the substituent effect on the spin crossover event. Variable temperature magnetic susceptibility and (57)Fe Mössbauer spectroscopy studies show that two of the complexes, [Fe(II)2(PMPT)2](BF4)4·H2O (N(4) substituent is pyrrolyl) and [Fe(II)2(PM(Ph)AT)2](BF4)4 (N(4) is N,N-diphenylamine), are stabilized in the [HS-HS] state between 300 and 2 K with weak antiferromagnetic interactions between the iron(II) centers. Five of the complexes showed gradual half spin crossover, from [HS-HS] to [HS-LS], with the following T(1/2) (K) values: 234 for [Fe(II)2(PMibT)2](BF4)4·3H2O (N(4) is isobutyl), 147 for [Fe(II)2(PMBzT)2](BF4)4 (N(4) is benzyl), 133 for [Fe(II)2(PM(CF3)PhT)2](BF4)4·DMF·H2O (N(4) is 3,5-bis(trifluoromethyl)phenyl), 187 for [Fe(II)2(PMPhT)2](BF4)4 (N(4) is phenyl), and 224 for [Fe(II)2(PMC16T)2](BF4)4 (N(4) is hexadecyl). Structure determinations carried out for three complexes, [Fe(II)2(PMPT)2](BF4)4·4DMF, [Fe(II)2(PMBzT)2](BF4)4·CH3CN, and [Fe(II)2(PM(Ph)AT)2](BF4)4·solvent, revealed that in all three complexes both iron(II) centers are stabilized in the high spin state at 90 K. A general and reliable 4-step route to PMRT ligands is also detailed.
Effect of counteranion X on the spin crossover properties of a family of diiron(II) triazole complexes [FeII 2(PMAT) 2](X)4
Publisher: American Chemical Society (ACS)
Date: 20-04-2011
DOI: 10.1021/IC200308K
Abstract: Seven diiron(II) complexes, [Fe(II)(2)(PMAT)(2)](X)(4), varying only in the anion X, have been prepared, where PMAT is 4-amino-3,5-bis{[(2-pyridylmethyl)-amino]methyl}-4H-1,2,4-triazole and X = BF(4)(-) (1), Cl(-) (2), PF(6)(-) (3), SbF(6)(-) (4), CF(3)SO(3)(-) (5), B(PhF)(4)(-) (6), and C(16)H(33)SO(3)(-) (7). Most were isolated as solvates, and the microcrystalline ([3], [4]·2H(2)O, [5]·H(2)O, and [6]·½MeCN) or powder ([2]·4H(2)O, and [7]·2H(2)O) s les obtained were studied by variable-temperature magnetic susceptibility and Mössbauer methods. A structure determination on a crystal of [2]·2MeOH·H(2)O, revealed it to be a [LS-HS] mixed low spin (LS)-high spin (HS) state dinuclear complex at 90 K, but fully high spin, [HS-HS], at 293 K. In contrast, structures of both [5]·¾IPA·H(2)O and [7]·1.6MeOH·0.4H(2)O showed them to be [HS-HS] at 90 K, whereas magnetic and Mössbauer studies on [5]·H(2)O and [7]·2H(2)O revealed a different spin state, [LS-HS], at 90 K, presumably because of the difference in solvation. None of these complexes undergo thermal spin crossover (SCO) to the fully LS form, [LS-LS]. The PF(6)(-) and SbF(6)(-) complexes, 3 and [4]·2H(2)O, appear to be a mixture of [HS-LS] and [HS-HS] at low temperature, and undergo gradual SCO to [HS-HS] on warming. The CF(3)SO(3)(-) complex [5]·H(2)O undergoes gradual, partial SCO from [HS-LS] to a mixture of [HS-LS] and [HS-HS] at T(1/2) ≈ 180 K. The B(PhF)(4)(-) and C(16)H(33)SO(3)(-) complexes, [6]·(1)/(2)MeCN and [7]·2H(2)O, are approximately [LS-HS] at all temperatures, with an onset of gradual SCO with T(1/2) > 300 K.
The Rich Tautomeric Behavior of Campestarenes
Publisher: Wiley
Date: 27-10-2016
Abstract: C estarenes are a new family of Schiff-base macrocycles that form selectively in a one-step synthesis. These macrocycles with five-fold symmetry show solvent-dependent tautomerization and dimerization or aggregation. In this paper, we have prepared new soluble c estarenes that do not aggregate. The initial single-crystal X-ray diffraction study of a c estarene reveals that these macrocycles are nearly flat. The tautomeric behavior of the c estarenes has been extensively studied by variable-temperature, multinuclear NMR spectroscopy, UV/Vis spectroscopy, and IR spectroscopy. In polar solvents, such as DMF, the molecules exist predominantly in their keto-enamine form, but the enol-imine tautomer is dominant in non-polar solvents. A detailed computational study of the tautomeric forms of c estarenes provides a theoretical basis for their behavior and corroborates the experimental data. The results of this study give the first comprehensive understanding of the electronic and spectroscopic properties of these pentagonal macrocycles.
Supramolecular anion recognition in water: synthesis of hydrogen-bonded supramolecular frameworks
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7SC00201G
Abstract: Charge-assisted hydrogen bonds between a tetratopic receptor and terephthalate anions assemble a switchable supramolecular framework material in water.
Amidinium⋯carboxylate frameworks: predictable, robust, water-stable hydrogen bonded materials
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1CC04782E
Abstract: This feature article describes the development of hydrogen bonded frameworks assembled using amidinium∙∙∙carboxylate hydrogen bonds, and discusses their structures, stabilities and applications.
Soluble Tetraaminotriptycene Precursors
Publisher: American Chemical Society (ACS)
Date: 04-08-2015
Abstract: An efficient route to soluble triptycene tetraamines, shape-persistent molecules containing two ortho-phenylenediamine motifs, is reported. These tetraamines are stable, prepared in good yields, easily purified by column chromatography, and can be readily condensed to give a range of imidazole and pyrazine derivatives.
A 1,2,3,4,5-Pentaphenylferrocene-Stoppered Rotaxane Capable of Electrochemical Anion Recognition
Publisher: Wiley
Date: 26-09-2011
Abstract: The chloride anion templated synthesis of an electrochemical anion sensory interlocked host system, prepared by the integration of redox-active 1,2,3,4,5-pentaphenylferrocene stopper groups into the structure of a rotaxane capable of binding anionic guests is described. Extensive (1)H NMR and electrochemical titration investigations were used to probe the anion recognition and sensing properties of the rotaxane, compared to the axle and model system components. A characteristic electrochemical response was observed for chloride binding by the rotaxane, which was attributed to the topologically constrained cavity of the interlocked host molecule.
Monolayer nanosheets formed by liquid exfoliation of charge-assisted hydrogen-bonded frameworks
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0SC06906J
Abstract: We report the liquid-phase ultrasonic exfoliation of two layered hydrogen-bonded frameworks into monolayer, micron-sized, and water-stable nanosheets (HONs) connected purely by hydrogen-bonding interactions.
Correspondence on “Crystalline Porous Organic Salt for Ultrarapid Adsorption/Desorption‐Based Atmospheric Water Harvesting by Dual Hydrogen Bond System”
Publisher: Wiley
Date: 19-01-2023
Abstract: In a recent Research Article, Ben and co‐workers reported a hydrogen‐bonded framework prepared from a 4 + tetra‐amidinium component and a 4 − tetra‐sulfonate component, termed CPOS‐6. They showed that CPOS‐6 could reversibly adsorb and desorb water over a narrow humidity window, and that this material offered potential for applications in atmospheric water harvesting. This conclusion was supported by experiments that showed the material was stable over 50 adsorption/desorption cycles and that the kinetics of these cycles were very rapid. In this Correspondence we present additional structural data regarding this framework in both its hydrated and dehydrated states and thus discern the mechanism of water binding. These data do not disagree with Ben and co‐workers’ findings: rather they emphasise how remarkable the cyclability and rapid kinetics of adsorption/desorption are, as these processes involve a complete crystal‐to‐crystal rearrangement of the framework.
A Structural Investigation of Anion–Triazole Interactions: Observation of “π‐Pockets” and “π‐Sandwiches”
Publisher: Wiley
Date: 03-2009
Anion binding in aqueous media by a tetra-triazolium macrocycle
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2OB25934F
Abstract: Three tetra-triazole macrocycles were synthesized in good yields by the copper(i)-catalysed cycloaddition of bis-triazole azides and bis-alkynes. One of these was alkylated to give a cyclic tetra-triazolium receptor, which complexes anions strongly in competitive DMSO-water mixtures. In 1 : 1 DMSO-water, the tetracationic receptor exhibits a preference for the larger halides, bromide and iodide, with all halides associating more strongly than the oxoanion, acetate. The sulfate dianion is complexed far more strongly than any of the monobasic anions (K(a) > 10(4) M(-1)). Quantum mechanics/molecular mechanics simulations corroborate the experimentally determined anion binding selectivity trends.
Shielded alkyl-functionalised rotaxane host cavities for improved anion recognition
Publisher: Informa UK Limited
Date: 26-10-2016
Copper(ii )-directed synthesis of neutral heteroditopic [2]rotaxane ion-pair host systems incorporating hydrogen and halogen bonding anion binding cavities
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7DT02832F
Abstract: Neutral heteroditopic [2]rotaxane ion-pair host systems were synthesised via a copper( ii )-directed metal template strategy and shown to undergo cooperative anion recognition with a co-bound zinc( ii ) cation.
Hysteretic spin crossover in iron(ii ) complexes of a new pyridine–triazole–pyrazine ligand is tuned by choice of NCE co-ligand
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CC43922D
Abstract: A family of three new mononuclear complexes of the general form [Fe(L(pz))2(NCE)2] has been prepared (L(pz) = 4-p-tolyl-3-(2-pyrazinyl)-5-(2-pyridyl)-1,2,4-triazole E = S, Se, BH3). All three exhibit spin crossover, in two cases with hysteresis, with T1/2 being predictably tuned by varying the coordinated anion.
A ferrocene imidazolium-based macrocycle as an electrochemical chemosensor for halide anions
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CE41851K
Solvent Polarity Predictably Tunes Spin Crossover T1/2 in Isomeric Iron(II) Pyrimidine Triazoles
Publisher: American Chemical Society (ACS)
Date: 16-05-2018
DOI: 10.1021/ACS.INORGCHEM.8B00128
Abstract: Two isomeric pyrimidine-based Rdpt-type triazole ligands were made: 4-(4-methylphenyl)-3-(2-pyrimidyl)-5-phenyl-4 H-1,2,4-triazole (L
Supramolecular frameworks based on 5,10,15,20-tetra(4-carboxyphenyl)porphyrins
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7DT04162D
Abstract: Hydrogen bonding is used to prepare porphyrin-containing supramolecular frameworks.
Correspondence on “Crystalline Porous Organic Salt for Ultrarapid Adsorption/Desorption‐Based Atmospheric Water Harvesting by Dual Hydrogen Bond System”
Publisher: Wiley
Date: 19-01-2023
Abstract: In a recent Research Article, Ben and co‐workers reported a hydrogen‐bonded framework prepared from a 4 + tetra‐amidinium component and a 4 − tetra‐sulfonate component, termed CPOS‐6. They showed that CPOS‐6 could reversibly adsorb and desorb water over a narrow humidity window, and that this material offered potential for applications in atmospheric water harvesting. This conclusion was supported by experiments that showed the material was stable over 50 adsorption/desorption cycles and that the kinetics of these cycles were very rapid. In this Correspondence we present additional structural data regarding this framework in both its hydrated and dehydrated states and thus discern the mechanism of water binding. These data do not disagree with Ben and co‐workers’ findings: rather they emphasise how remarkable the cyclability and rapid kinetics of adsorption/desorption are, as these processes involve a complete crystal‐to‐crystal rearrangement of the framework.
New complexation behaviour of the potentially bis-terdentate triazole based ligands PMAT and PMPT : Fe III 4 oxo-bridged metallomacrocycles
Publisher: Elsevier BV
Date: 2016
Coordination Polymers from Functionalized Bipyrimidine Ligands and Silver(I) Salts
Publisher: American Chemical Society (ACS)
Date: 06-03-2018
Room Temperature Hydrolysis of Benzamidines and Benzamidiniums in Weakly Basic Water
Publisher: American Chemical Society (ACS)
Date: 22-09-2021
A new halogen bonding 1,2-iodo-triazolium-triazole benzene motif for anion recognition
Publisher: Elsevier BV
Date: 11-2021
What's in an Atom? A Comparison of Carbon and Silicon‐Centred Amidinium⋅⋅⋅Carboxylate Frameworks**
Publisher: Wiley
Date: 15-12-2020
(Self) assembled news: recent highlights from the Supramolecular Chemistry literature (Quarter 3, 2023)
Publisher: Informa UK Limited
Date: 26-10-2023
Increased Halide Recognition Strength by Enhanced Intercomponent Preorganisation in Triazolium Containing [2]Rotaxanes
Publisher: Wiley
Date: 22-11-2013
Abstract: Three triazolium-based [2]rotaxanes containing different sized axle and macrocycle components were synthesised in good yields (40-57%) through chloride anion templation. The anion recognition properties of the interlocked receptor systems were investigated using (1)H NMR titration experiments: all three rotaxanes display impressive selectivities for halide anions over the more basic oxoanion acetate. The rotaxanes incorporating shorter, more rigid axle components with aryl-substituted triazolium groups display substantially higher anion binding affinities than those with longer, bis-alkyl-substituted heterocycles, which is attributed to the increased intercomponent preorganisation afforded by the smaller axle component. Computational DFT and molecular dynamics simulations composed of unconstrained and umbrella s ling simulations corroborate the experimental observations.
Fluorescent Charge-Assisted Halogen-Bonding Macrocyclic Halo-Imidazolium Receptors for Anion Recognition and Sensing in Aqueous Media
Publisher: American Chemical Society (ACS)
Date: 03-07-2012
DOI: 10.1021/JA302213R
Abstract: The synthesis and anion binding properties of a new family of fluorescent halogen bonding (XB) macrocyclic halo-imidazolium receptors are described. The receptors contain chloro-, bromo-, and iodo-imidazolium motifs incorporated into a cyclic structure using naphthalene spacer groups. The large size of the iodine atom substituents resulted in the isolation of anti and syn conformers of the iodo-imidazoliophane, whereas the chloro- and bromo-imidazoliophane analogues exhibit solution dynamic conformational behavior. The syn iodo-imidazoliophane isomer forms novel dimeric isostructural XB complexes of 2:2 stoichiometry with bromide and iodide anions in the solid state. Solution phase DOSY NMR experiments indicate iodide recognition takes place via cooperative convergent XB-iodide 1:1 stoichiometric binding in aqueous solvent mixtures. (1)H NMR and fluorescence spectroscopic titration experiments with a variety of anions in the competitive CD(3)OD/D(2)O (9:1) aqueous solvent mixture demonstrated the bromo- and syn iodo-imidazoliophane XB receptors to bind selectively iodide and bromide respectively, and sense these halide anions exclusively via a fluorescence response. The protic-, chloro-, and anti iodo-imidazoliophane receptors proved to be ineffectual anion complexants in this aqueous methanolic solvent mixture. Computational DFT and molecular dynamics simulations corroborate the experimental observations that bromo- and syn iodo-imidazoliophane XB receptors form stable cooperative convergent XB associations with bromide and iodide.
A Rapid and Straightforward Supramolecular Self-Assembly Experiment To Prepare and Characterize a Triple Helicate Complex
Publisher: American Chemical Society (ACS)
Date: 19-02-2018
Suppression of savanna ants alters invertebrate composition and influences key ecosystem processes.
Publisher: Wiley
Date: 06-2016
DOI: 10.1890/15-1713.1
Abstract: In almost every ecosystem, ants (Hymenoptera: Formicidae) are the dominant terrestrial invertebrate group. Their functional value was highlighted by Wilson (1987) who famously declared that invertebrates are the "little things that run the world." However, while it is generally accepted that ants fulfil important functions, few studies have tested these assumptions and demonstrated what happens in their absence. We report on a novel large-scale field experiment in undisturbed savanna habitat where we examined how ants influence the abundance of other invertebrate taxa in the system, and affect the key processes of decomposition and herbivory. Our experiment demonstrated that ants suppressed the abundance and activity of beetles, millipedes, and termites, and also influenced decomposition rates and levels of herbivory. Our study is the first to show that top-down control of termites by ants can have important ecosystem consequences. Further studies are needed to elucidate the effects ant communities have on other aspects of the ecosystem (e.g., soils, nutrient cycling, the microbial community) and how their relative importance for ecosystem function varies among ecosystem types (e.g., savanna vs. forest).
Vibrational mode analysis of hydrogen-bonded organic frameworks (HOFs): synchrotron infrared studies
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CP00796G
Abstract: Vibrational analysis of hydrogen-bonded organic frameworks (HOFs). Characterisation of structure, morphology and host–guest properties using synchrotron infrared spectroscopy and periodic density functional theory.
An Investigation of Five Component [3+2] Self-Assembled Cage Formation Using Amidinium···Carboxylate Hydrogen Bonds
Publisher: CSIRO Publishing
Date: 05-07-2021
DOI: 10.1071/CH21101
Abstract: The assembly of hydrogen bonded cages using amidinium···carboxylate hydrogen bonding interactions was investigated. A new tris-amidinium hydrogen bond donor tecton based on a tetraphenylmethane scaffold was prepared and its self-assembly with the terephthalate anion studied, and a new tricarboxylate hydrogen bond acceptor tecton was synthesised and its assembly with the 1,3-benzenebis(amidinium) hydrogen bond donor explored. In both cases, molecular modelling indicated that the formation of the cages was geometrically feasible and 1H NMR spectroscopic evidence was consistent with interactions between the components in competitive d6-DMSO solvent mixtures. DOSY NMR spectroscopy of both systems indicated that both components diffuse at the same rate as each other, and diffusion coefficients were consistent with cage formation, and with the formation of assemblies significantly larger than the in idual components. An X-ray crystal structure showed that one of the assemblies did not have the desired cage structure in the solid state.
Hydrogen atoms in supramolecular chemistry: a structural perspective. Where are they, and why does it matter?
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3CS00516J
Abstract: This Tutorial Review discusses the opportunities and challenges of locating hydrogen atoms in X-ray crystal structures, particularly those of supramolecular systems.
Host–guest interactions of catechol and 4-ethylcatechol with surface-immobilized blue-box molecules
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA00556K
Abstract: Surface-immobilized Blue Box molecules remove large amounts of the highly toxic catechol and 4-ethylcatechol from aqueous media, catalyzing the formation of a thin film of poly(catechol).
Simple acyclic molecules containing a single charge-assisted O–H group can recognize anions in acetonitrile : water mixtures
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1OB00282A
Abstract: Simple cationic compounds containing O–H hydrogen bond donors bind anions very strongly in acetonitrile, and with moderate strength in 9 : 1 acetonitrile : water.
Molecular Tectonics: A Node-and-Linker Building Block Approach to a Family of Hydrogen Bonded Frameworks
Publisher: American Chemical Society (ACS)
Date: 03-05-2019
DOI: 10.26434/CHEMRXIV.8067176.V1
Abstract: While numerous hydrogen bonded organic frameworks (HOFs) have been reported, typically these cannot be prepared predictably or in a modular fashion. In this work, we report a family of nine diamondoid crystalline porous frameworks assembled via hydrogen bonding between poly-amidinium and poly-carboxylate tectons in aqueous media. Importantly, both the cationic and anionic components can be varied and additional functionality can be incorporated into the frameworks, which show good stability including to prolonged heating in DMSO or water.
Using Machine Learning to Link Climate, Phylogeny and Leaf Traits in Eucalypts Through a 50-fold Expansion of Current Leaf Trait Datasets
Publisher: California Digital Library (CDL)
Date: 05-05-2023
DOI: 10.32942/X2DG6F
Abstract: Leaf size varies within and between species, and previous work has linked this variation to the environment and evolutionary history separately. However, many previous studies fail to interlink both factors and are often data limited. To address this, our study developed a new workflow using machine learning to automate the extraction of leaf traits (leaf area, largest in-circle area and leaf curvature) from herbarium collections of Australian eucalypts (Eucalyptus, Angophora and Corymbia). Our dataset included 136,599 measurements, expanding existing data on this taxon’s leaf area by roughly 50-fold. With this dataset, we were able to confirm global positive relationships between leaf area and mean annual temperature and precipitation. Furthermore, we linked this trait-climate relationship to phylogeny, revealing large variation at the within-species level, potentially due to gene flow suppressing local adaptation. At deeper phylogenetic levels, the relationship strengthens and the slope converges towards the overall eucalypt slope, suggesting that the effect of gene flow relaxes just above the species level. The strengthening of trait-climate correlations just beyond the intraspecific level may represent a widespread phenomenon across various traits and taxa. Future studies may unveil these relationships with the larger s le sizes of new trait datasets generated through machine learning.
Charge “mis-matched” hydrogen bonded frameworks for cation exchange and dye sorption
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3CC00553D
Abstract: Anionic hydrogen bonded frameworks were synthesised from di or tetra-amidinium hydrogen bond donor components and a charge “mis-matched” tecton possessing a 5− charge but only four hydrogen bond accepting groups.
Post-synthetic modification of a porous hydrocarbon cage to give a discrete Co24 organometallic complex
Publisher: American Chemical Society (ACS)
Date: 30-03-2022
DOI: 10.26434/CHEMRXIV-2022-9GW50
Abstract: A new alkyne-based hydrocarbon cage was synthesized in high overall yield using alkyne–alkyne coupling in the cage forming step. The cage is porous and displays a moderately high BET surface area (546 m2 g–1). The cage loses crystallinity on activation and thus is porous in its amorphous form, while very similar cages have been either non-porous, or retained crystallinity on activation. Reaction of the cage with Co2(CO)8 results in exhaustive metalation of its 12 alkyne groups to give the Co24(CO)72 adduct of the cage in good yield.
Anion coordination chemistry using O–H groups
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8CS00828K
Abstract: This review details the use of O–H⋯anion interactions in synthetic receptors, anion transport, self-assembly and catalysis.
Effect of pressure and light on the spin transition behavior of the dinuclear iron(II) compound [FeII2(PMAT)2](BF4)4⋅DMF
Publisher: AIP Publishing
Date: 28-04-2008
DOI: 10.1063/1.2911918
Abstract: We present the results of our investigation into the effects of pressure and light on the high spin⇆low spin transition behavior of the dinuclear iron(II) compound [FeII2(PMAT)2](BF4)4⋅DMF. It is found that increased pressure favors the stabilization of the system through a transition from the (HS-HS) state to the (HS-LS) state. Interestingly, even under the pressure of 10.3kbar and low temperatures, there is no evidence of the (LS-LS) form. Irradiation of the (HS-LS) state with light induces a transition from (HS-LS) to a (HS-HS) metastable state. These results underline the role of intermolecular interactions in the stabilization of the dinuclear lattice system.
Molecular Tectonics: A Node‐and‐Linker Building Block Approach to a Family of Hydrogen‐Bonded Frameworks
Publisher: Wiley
Date: 03-07-2019
Abstract: While numerous hydrogen-bonded organic frameworks (HOFs) have been reported, typically these cannot be prepared predictably or in a modular fashion. In this work, we report a family of nine diamondoid crystalline porous frameworks assembled via hydrogen bonding between poly-amidinium and poly-carboxylate tectons. The frameworks are prepared at room temperature in either water or water/alcohol mixtures. Importantly, both the cationic and anionic components can be varied and additional functionality can be incorporated into the frameworks, which show good stability including to prolonged heating in DMSO or water.
Selective Removal of Sulfate from Water by Precipitation with a Rigid Bis‐amidinium Compound
Publisher: Wiley
Date: 14-02-2023
Abstract: A simple, readily prepared biphenyl bis‐amidinium compound ( 1⋅Cl 2 ) is able to selectively precipitate sulfate from water. The precipitant is effective at concentrations as low as 1 mM and shows complete selectivity against monovalent anions, and high selectivity even against CO 3 2− and HPO 4 2− . It is highly effective ( % sulfate removed) in both seawater and highly acidic conditions relevant to mining waste‐streams. X‐ray crystallography reveals that 1⋅SO 4 forms a tightly packed, anhydrous, structure where each sulfate anion receives eight hydrogen bonds from amidinium N−H hydrogen bond donors.
A Bidentate Halogen-Bonding Bromoimidazoliophane Receptor for Bromide Ion Recognition in Aqueous Media
Publisher: Wiley
Date: 14-01-2011
Easily-prepared hydroxy-containing receptors recognise anions in aqueous media
Publisher: American Chemical Society (ACS)
Date: 21-12-2018
DOI: 10.26434/CHEMRXIV.7497803.V1
Abstract: Despite their readily availability, O–H groups have received relatively little attention as anion recognition motifs. Here, we report two simple hydroxy-containing anion receptors that are prepared in two facile steps followed by anion exchange, without the need for chromatographic purification at any stage. These receptors contain a pyridinium bis(amide) motif as well as hydroxyphenyl groups, and bind mono- and alent anions in 9:1 CD3CN:D2O, showing a selectivity preference for sulfate. Notably, a “model” receptor that does not contain hydroxy groups shows only very weak sulfate binding in this competitive solvent mixture.
Tuning the tautomeric behavior of tris(salicylaldimines)
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7OB02058A
Abstract: The tautomeric state of the versatile tris(salicylaldimine) (TSAN) motif is shown to be tunable through the electron delocalization properties of its peripheral groups.
Investigating the effect of macrocycle size in anion templated imidazolium-based interpenetrated and interlocked assemblies
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2OB26237A
Abstract: The effect of varying the size of the macrocycle component on the formation of anion templated imidazolium interpenetrated assemblies is investigated. Two different approaches to reducing the macrocycle size are undertaken and the stabilities of the resulting pseudorotaxanes incorporating substituted imidazolium threading components studied using (1)H NMR spectroscopy. Novel imidazolium axle containing interlocked rotaxane host structures are synthesised using chloride anion templated amide condensation and 'stoppering' methods, and the anion recognition properties of the 'stoppered' rotaxane investigated.
Post‐Synthetic Modification of a Porous Hydrocarbon Cage to Give a Discrete Co24 Organometallic Complex**
Publisher: Wiley
Date: 21-07-2022
Abstract: A new alkyne‐based hydrocarbon cage was synthesized in high overall yield using alkyne‐alkyne coupling in the cage forming step. The cage is porous and displays a moderately high BET surface area (546 m 2 g −1 ). The cage loses crystallinity on activation and thus is porous in its amorphous form, while very similar cages have been either non‐porous, or retained crystallinity on activation. Reaction of the cage with Co 2 (CO) 8 results in exhaustive metalation of its 12 alkyne groups to give the Co 24 (CO) 72 adduct of the cage in good yield.
Copper-induced N–N bond cleavage results in an octanuclear expanded-core grid-like complex
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC32018E
Abstract: Reaction of copper(I) acetate and 4-amino-3,5-di(2-pyridyl)-1,2,4-triazole (adpt) in methanol under ambient conditions yields octanuclear [Cu(II)(8)(dpt)(4)(OH)(4)(OAc)(8)] OAc = acetate anion, and dpt(-) = anion of deaminated adpt, 3,5-di(2-pyridyl)-1,2,4-triazolate. However, reaction of copper(ii) acetate with dptH gives tetranuclear [Cu(II)(4)(dpt)(2)(OH)(OMe)(OAc)(4)].
Jack of all trades: anion and transition metal binding by bis-triazole receptors
Publisher: Informa UK Limited
Date: 29-05-2012
Iron-based energy storage materials from carbon dioxide and scrap metal
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0MA00588F
Abstract: Ferrous oxalate from carbon dioxide and scrap mild steel stores more energy and carbon than irons oxides prepared from oxalates.
Hydrogen Bonding Guests Direct the Packing of a Small Organic Cage Molecule
Publisher: American Chemical Society (ACS)
Date: 30-04-2019
DOI: 10.26434/CHEMRXIV.8052182.V1
Abstract: A small organic cage molecule ( 1 ) containing six nitrile groups was crystallized in the presence of a number of guests with hydrogen bond donor groups, and from different solvents. In total, eight crystal structures of 1 were obtained, six of which are guest-free and two of which are co-crystals. When the guest was resorcinol or pyrogallol co-crystals did not form, but the presence of the guests directed formation of new crystalline phases that were not observed when the cage was crystallized alone. When the guest was hydroquinone or diaminobenzene, it was possible to isolate co-crystals where the guest hydrogen bonds to some of the nitrile groups of the cage.
Water Sorption Controls Extreme Single‐Crystal‐to‐Single‐Crystal Molecular Reorganization in Hydrogen Bonded Organic Frameworks
Publisher: Wiley
Date: 17-08-2022
Abstract: As hydrogen bonded frameworks are held together by relatively weak interactions, they often form several different frameworks under slightly different synthesis conditions and respond dynamically to stimuli such as heat and vacuum. However, these dynamic restructuring processes are often poorly understood. In this work, three isoreticular hydrogen bonded organic frameworks assembled through charge‐assisted amidinium⋅⋅⋅carboxylate hydrogen bonds ( 1 C/C , 1 Si/C and 1 Si/Si ) are studied. Three distinct phases for 1 C/C and four for 1 Si/C and 1 Si/Si are fully structurally characterized. The transitions between these phases involve extreme yet recoverable molecular‐level framework reorganization. It is demonstrated that these transformations are related to water content and can be controlled by humidity, and that the non‐porous anhydrous phase of 1 C/C shows reversible water sorption through single crystal to crystal restructuring. This mechanistic insight opens the way for the future use of the inherent dynamism present in hydrogen bonded frameworks.
Selective Removal of Sulfate from Water by Precipitation with a Rigid Bis‐amidinium Compound
Publisher: Wiley
Date: 14-02-2023
Abstract: A simple, readily prepared biphenyl bis‐amidinium compound ( 1⋅Cl 2 ) is able to selectively precipitate sulfate from water. The precipitant is effective at concentrations as low as 1 mM and shows complete selectivity against monovalent anions, and high selectivity even against CO 3 2− and HPO 4 2− . It is highly effective ( % sulfate removed) in both seawater and highly acidic conditions relevant to mining waste‐streams. X‐ray crystallography reveals that 1⋅SO 4 forms a tightly packed, anhydrous, structure where each sulfate anion receives eight hydrogen bonds from amidinium N−H hydrogen bond donors.
Robust organic cages prepared using hydrazone condensation display sulfate/hydrogenphosphate selectivity in water
Publisher: American Chemical Society (ACS)
Date: 16-12-2021
DOI: 10.26434/CHEMRXIV-2021-QQHS8
Abstract: Two robust hexacationic cages incorporating either urea or isophthalamide motifs were synthesized via a short and high-yielding synthetic pathway using hydrazone condensation reactions in water for the cage forming step. Stability testing revealed that the cages are stable to a range of stimuli in water and in organic solvents. The urea containing cage can bind anions in pure water, and displays strong and selective binding of SO42– over HPO42–. The isophthalamide containing cage binds SO42– only weakly in 1:1 D2O:d6-DMSO but displays strong and cooperative binding of two HPO42– anions. Combined quantum mechanical/annealed molecular dynamics simulations suggest that the remarkable differences in anion selectivity are largely a result of the differing flexibilities of the two cages.
Recent advances in self-assembled amidinium and guanidinium frameworks
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8DT05030A
Abstract: Recent advances in amidinium and guanidinium-containing hydrogen-bonded framework materials are highlighted.
Room-temperature spin crossover and Langmuir–Blodgett film formation of an iron(ii) triazole complex featuring a long alkyl chain substituent: the tail that wags the dog
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0CC01008A
Abstract: [Fe(II)(C(16)dpt)(2)(NCS)(2)].(2/3)H(2)O displays temperature-mediated spin crossover (SCO) with T((1/2)) = 290 K and the long alkyl chain substituent on the dipyridyltriazole ligand facilitates the formation of a stable Langmuir-Blodgett film at an air-water interface.
A three dimensional hydrogen bonded organic framework assembled through antielectrostatic hydrogen bonds
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC06707H
Abstract: A 3D hydrogen bonded organic framework was assembled in water from tetraamidinium cations and antielectrostatically hydrogen bonded bicarbonate dimers.
A rotaxane host system containing integrated triazole C-H hydrogen bond donors for anion recognition
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2OB27229F
Abstract: Two rotaxanes incorporating a 3,5-bis(triazole)-pyridinium axle component have been prepared using either an anion templated amide condensation or ring closing metathesis (RCM) clipping strategy. The respective yields of interlocked receptor were found to be significantly higher when the RCM clipping synthetic route was used. Proton NMR titration experiments in competitive 1 : 1 CDCl(3)-CD(3)OD solvent media reveal that the rotaxane prepared by the clipping procedure is selective for halide anions over larger, more basic oxoanions. Interestingly, the interlocked host displays an unusual preference for bromide over other halide anions.
Structural Study of Triazole and Amide Containing Anion-Templated Pseudorotaxanes
Publisher: American Chemical Society (ACS)
Date: 23-05-2014
DOI: 10.1021/CG500420U
Understanding the Forces That Govern Packing: A Density Functional Theory and Structural Investigation of Anion−π–Anion and Nonclassical C–H···Anion Interactions
Publisher: American Chemical Society (ACS)
Date: 13-09-2012
DOI: 10.1021/IC3014688
Abstract: The ability of Ni(II) coordinated 4-pyrrolyl-3,5-di(2-pyridyl)-1,2,4-triazole (pldpt) to establish multiple anion-π interactions is analyzed. Experimentally, such complexes were previously shown to form strong anion-π interactions, including "π-pocket" and "π-sandwiched" motifs, in the crystal lattice. In the latter, the triazole ring is "sandwiched" by two anions forming a ternary anion-π-anion assembly (π-sandwich) which, surprisingly, gave about 0.2 Å shorter anion-π distances than in binary assemblies (where only one side of the triazole participates in the anion binding), indicating the possibility of cooperativity. In depth analysis, using dispersion-corrected density functional theory (DFT, BP86-D/def2-TZVP level of theory), shows that this ternary anion-π-anion interaction is slightly less energetically favorable than the binary anion-π interactions in isolation. Hence, the sandwich interaction is not cooperative (E(coop) is positive), but, as E(coop) contributes less than 1.5% of the total interaction energy (which is dominated by the strong electrostatic attraction of the anions to the highly π-acidic Ni(II)-coordinated triazole ring), the presence of nonclassical C-H···anion hydrogen bonds can offset this, making the short anion-π sandwich interactions the most favorable solid state conformation.
Anion-templated hexagonal nanotubes
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5SC02577J
Abstract: O–H⋯Br − hydrogen bonding gives water-stable hexagonal nanotubes.
Anion Templated Crystal Engineering of Halogen Bonding Tripodal Tris(halopyridinium) Compounds
Publisher: American Chemical Society (ACS)
Date: 20-02-2020
DOI: 10.26434/CHEMRXIV.11862900.V1
Abstract: In this work four new tripodal tris(halopyridinium) receptors containing potentially halogenbonding groups were prepared. The ability of the receptors to bind anions in competitiveCD 3 CN/d 6 -DMSO was studied using 1 H NMR titration experiments, which revealed that thereceptors bind chloride anions more strongly than more basic acetate or other halide ions.The solid state self–assembly of the tripodal receptors with halide anions was investigated byX-ray crystallography. The nature of the structures was dependent on the choice of halideanion, as well as the crystallisation solvent. Halogen bond lengths as short as 80% of the sumof the van der Waals radii were observed, which is shorter than any halogen bonds involvinghalopyridinium receptors in the Cambridge Structural Database.
A Bis-Triazacyclononane Tris-Pyridyl N9 -Azacryptand “Beer Can” Receptor for Complexation of Alkali Metal and Lead(II) Cations
Publisher: Wiley
Date: 19-06-2018
Abstract: A new bis-triazacyclononane tris-pyridyl N
Protein-induced modifications in crystal morphology of a hydrogen-bonded organic framework
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3TA04707E
Use of modulators and light to control crystallisation of a hydrogen bonded framework
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1CC06164J
Abstract: Modulators, light and solvent are used to control the crystal size of a hydrogen bonded framework.
Tuneable reversible redox of cobalt(iii ) carbazole complexes
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7DT00295E
Abstract: Four structurally characterised [Co III L R/R′ 2 ]BF 4 complexes, of four acyclic bis(triazolyl)carbazole ligands L R/R′ , all show a pair of reversible one-electron redox processes which can be tuned by variation of the carbazole substituents R.
A Three Dimensional Hydrogen Bonded Organic Framework Assembled Through Antielectrostatic Hydrogen Bonds
Publisher: American Chemical Society (ACS)
Date: 30-08-2019
DOI: 10.26434/CHEMRXIV.9746195.V1
Abstract: Crystalline 3D hydrogen bonded frameworks are assembled in water from tetrahedral tetraamidinium cations and antielectrostatically hydrogen bonded bicarbonate dimers. The framework forms in water, and represents a clear demonstration of the potency of these anti-Coulombic hydrogen bonds. Gentle heating of the framework (50 °C) releases CO2 and water to give the neutral tetraamidine compound.
Anion and Cation Effects on Anion-Templated Assembly of Tetrahydroxytriptycene
Publisher: American Chemical Society (ACS)
Date: 20-10-2015
Hydrogen Bonding Guests Direct the Packing of a Small Organic Cage Molecule
Publisher: American Chemical Society (ACS)
Date: 18-06-2019
Metal organic frameworks from extended, conjugated pentiptycene-based ligands
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5CE00886G
Room temperature hydrolysis of benzamidines and benzamidiniums in weakly basic water
Publisher: American Chemical Society (ACS)
Date: 17-08-2021
DOI: 10.26434/CHEMRXIV-2021-RW953
Abstract: Benzamidinium compounds have found widespread use in both medicinal and supramolecular chemistry. In this work, we show that benzamidiniums hydrolyse at room temperature in aqueous base to give the corresponding primary amide. This reaction has a half-life of 300 days for unsubstituted benzamidinium at pH 9, but is relatively rapid at higher pHs (e.g. t1/2 = 6 days at pH 11 and 15 hours at pH 13). Quantum chemistry combined with first principles kinetic modelling can reproduce these trends and explain them in terms of the dominant pathway being initiated by attack of HO– on benzamidine. Incorporation of the amidinium motif into a hydrogen bonded framework offers a substantial protective effect against hydrolysis.
Antielectrostatically hydrogen bonded anion dimers: counter-intuitive, common and consistent
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CE01118H
Abstract: A Cambridge Structural Database survey reveals that antielectrostatically hydrogen bonded dimers occur frequently between a wide range of anions.
Related Organisations
University Of Oxford
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
Discovery Projects - Grant ID: DP230100190
Start Date: 03-2023
End Date: 02-2026
Amount: $379,997.00
Funder: Australian Research Council
View Funded ActivityARC Future Fellowships - Grant ID: FT210100495
Start Date: 2022
End Date: 12-2025
Amount: $975,331.00
Funder: Australian Research Council
View Funded ActivityDiscovery Early Career Researcher Award - Grant ID: DE170100200
Start Date: 2017
End Date: 12-2019
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP200100535
Start Date: 2020
End Date: 12-2022
Amount: $420,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE190100160
Start Date: 2019
End Date: 12-2019
Amount: $368,994.00
Funder: Australian Research Council
View Funded Activity