ORCID Profile
0000-0002-7832-5716
Current Organisation
Université de Fribourg
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Publisher: Wiley
Date: 05-10-2021
Abstract: Stimuli‐responsive crystals capable of energy conversion have emerged as promising materials for smart sensors, actuators, wearable devices, and robotics. Here, a novel ferrocene‐based organic molecule crystal (Fc‐Cz) that possesses anisotropic piezoelectric, optical, and mechanical properties is reported. It is demonstrated that the new crystal Fc‐Cz can be used as an ultrasensitive piezoelectric material in fabricating strain sensors. The flexible sensor made of crystal Fc‐Cz can detect small strains/deformations and motions with a fast response speed. Analysis based on density functional theory (DFT) indicates that an external pressure can affect the dipole moment by changing the molecular configuration of the asymmetric single crystal Fc‐Cz in the crystalline state, leading to a change of polarity, and thereby an enhanced dielectric constant. This work demonstrates a new artificial organic small molecule for high‐performance tactile sensors, indicating its great potential for developing low‐cost flexible wearable sensors.
Publisher: MDPI AG
Date: 31-12-2019
Abstract: In this report, we explore the use of supercritical CO2 (scCO2) in the synthesis of well-known metal-organic frameworks (MOFs) including Zn-MOF-74 and UiO-66, as well as on the preparation of [Cu24(OH-mBDC)24]n metal-organic polyhedra (MOPs) and two new MOF structures {[Zn2(L1)(DPE)]∙4H2O}n and {[Zn3(L1)3(4,4′-azopy)]∙7.5H2O}n, where BTC = benzene-1,3,5-tricarboxylate, BDC = benzene-1,4-dicarboxylate, L1 = 4-carboxy-phenylene-methyleneamino-4-benzoate, DPE = 1,2-di(4-pyridyl)ethylene, 4.4′-azopy = 4,4′- azopyridine, and compare the results versus traditional solvothermal preparations at low temperatures (i.e., 40 °C). The objective of the work was to see if the same or different products would result from the scCO2 route versus the solvothermal method. We were interested to see which method produced the highest yield, the cleanest product and what types of morphology resulted. While there was no evidence of additional meso- or macroporosity in these MOFs/MOPs nor any significant improvements in product yields through the addition of scCO2 to these systems, it was shown that the use of scCO2 can have an effect on crystallinity, crystal size and morphology.
Publisher: American Chemical Society (ACS)
Date: 25-05-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TC05547E
Abstract: Non-doped organic light-emitting diodes (OLEDs) using pyrene-based AIE luminogens as emitters displayed sky-blue light at 492 nm at a low turn-on voltage (3.1 V) with a maximum luminance of 15 750 cd m −2 and a current efficiency of 7.34 cd A −1 with a low efficiency roll-off.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TC03022A
Abstract: A series of pyrene-based AIEgens have been employed in the preparation of fluorescent inks with less colour migration for anti-counterfeiting applications over the ultra-low to high concentration range and avoids the ACQ effect.
Publisher: Wiley
Date: 13-07-2022
Abstract: The proposed concept of aggregation‐induced emission (AIE) has offered an efficient strategy to design high‐performance luminescent materials. Herein, three blue emitters containing a pyrene core decorated with either triphenylamine or tetraphenylethylene units are presented. The designed compounds Py‐TPA and Py‐2TPE are AIE or active materials with blue emission from 464 to 478 nm in the solid state, whereas Py‐2TPA is not. Moreover, the enhanced thermal stability of compounds Py‐TPA and Py‐2TPE allows for their utilization as emitter layers for the fabrication of blue organic light‐emitting diode (OLED) devices. The devices exhibit excellent electroluminescence emission with maximum λ max em in the range 456–482 nm with a maximum external quantum efficiency of 7.27%, high exciton utilization efficiency (77.3%), and low turn‐on voltage (≤3.1 V), as well as low‐efficiency roll‐off. Theoretical calculations reveal that the high exciton utilization efficiency ( ƞ r ) originates from the triplet excitons at T 2 to the lowest single excited (S 1 ) state via a reverse intersystem crossing process following the principle of the “hot exciton” mechanism. This article not only provides powerful evidence revealing the advantages of pyrene‐based AIEgens for OLED applications, but also offers a new approach for designing pyrene‐based “hot exciton” materials for next‐generation OLEDs.
Publisher: American Chemical Society (ACS)
Date: 21-06-2022
Abstract: Hydrogen bonds not only play a crucial role in the life sciences but also endow molecules with fantastic physical and chemical properties, which help in the realization of their high-tech applications. This work presents an efficient strategy for achieving highly efficient solid-state dual-emission blue emitters with mechanical force-induced enhanced emission properties via intermolecular hydrogen bonds via novel pyrene-based intermediates, namely, 1,3,6,8-tetrabromo-2,7-dihydroxypyrene (
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1DT01330K
Abstract: Unusual scandium calix[ n ]arenes ( n = 4, 6, 8) have been isolated, structurally characterized and screened for their toxicity and ability to catalyze ring opening polymerizations (ROP) of cyclohexene oxide.
Publisher: American Chemical Society (ACS)
Date: 26-05-2021
Publisher: Elsevier BV
Date: 02-2021
Publisher: American Chemical Society (ACS)
Date: 27-01-2020
DOI: 10.1021/ACS.INORGCHEM.9B03239
Abstract: Reaction of [ReOCl
Publisher: Wiley
Date: 09-09-2020
Abstract: Aggregation‐induced emission (AIE) luminogens are an important type of advanced functional materials with fantastic optical properties and have found potential applications in organic electronics, biochemistry, and molecular imaging. Herein, this article presents a novel application of AIE luminogens (AIEgens) for efficient exfoliation of layered transition metal dichalcogenides (TMDs, such as MoS 2 and WSe 2 ). From the 1 H NMR spectroscopic analysis, the designed AIEgens can insert into the space between layers of MoS 2 in ethanol solution and the dynamic molecular rotation against the weak interactions affords large‐scale few‐layer MoS 2 nanosheets (7–8 layers) with enhanced smoothness. The 3D AIEgens play a significant role in preserving the crystal lattice of MoS 2 even at high pressure ( GPa). More importantly, the new approach can also be used for exfoliation of WSe 2 to achieve large‐scale few‐layer nanosheets. The present work thus provides a facile and high yielding synthetic method for accessing on a large scale 2D layered materials with enhanced properties for high‐technology applications.
Publisher: American Chemical Society (ACS)
Date: 18-07-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3CS00251A
No related grants have been discovered for Timur Ashirov.