ORCID Profile
0000-0003-4945-7485
Current Organisations
Universidade de São Paulo
,
Universidade Federal de São Carlos
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Publisher: International Union of Crystallography (IUCr)
Date: 17-05-2019
DOI: 10.1107/S2056989019006765
Abstract: The title compound, C 15 H 13 BrO 2 S, comprises three different substituents bound to a central (and chiral) methine-C atom, i.e . (4-bromophenyl)sulfanyl, benzaldehyde and methoxy residues: crystal symmetry generates a racemic mixture. A twist in the molecule is evident about the methine-C—C(carbonyl) bond as evidenced by the O—C—C—O torsion angle of −20.8 (7)°. The dihedral angle between the bromobenzene and phenyl rings is 43.2 (2)°, with the former disposed to lie over the oxygen atoms. The most prominent feature of the packing is the formation of helical supramolecular chains as a result of methyl- and methine-C—H...O(carbonyl) interactions. The chains assemble into a three-dimensional architecture without directional interactions between them. The nature of the weak points of contacts has been probed by a combination of Hirshfeld surface analysis, non-covalent interaction plots and interaction energy calculations. These point to the importance of weaker H...H and C—H...C interactions in the consolidation of the structure.
Publisher: International Union of Crystallography (IUCr)
Date: 09-06-2020
DOI: 10.1107/S2056989020007380
Abstract: The title compound, C 20 H 20 N 4 O 3 , is constructed about a tri-substituted 1,2,3-triazole ring, with the substituent at one C atom flanked by the C and N atoms being a substituted amide group, and with the adjacent C and N atoms bearing phenyl and benzyl groups, respectively the dihedral angle between the pendant phenyl rings is 81.17 (12)°, indicative of an almost orthogonal disposition. In the crystal, pairwise amide-N—H...O(carbonyl) hydrogen bonds lead to a centrosymmetric dimer incorporating methylene-C—H...π(benzene) interactions. The dimers are linked into a supramolecular layer in the ab plane via methylene-C—H...N(azo) and benzene-C—H...O(amide) interactions the layers stack along the c -axis direction without directional interactions between them. The above-mentioned intermolecular contacts are apparent in the analysis of the calculated Hirshfeld surface, which also provides evidence for short inter-layer H...C contacts with a significant dispersion energy contribution.
Publisher: Walter de Gruyter GmbH
Date: 18-07-2020
Abstract: C 19 H 24 N 2 O 6 , monoclinic, P 2 1 (no. 4), a = 8.3611(7) Å, b = 9.0521(8) Å, c = 13.8988(8) Å, β = 106.710(5)°, V = 1007.52(14) Å 3 , Z = 2, R gt ( F ) = 0.0428, wR ref ( F 2 ) = 0.1174, T = 293(2) K.
Publisher: International Union of Crystallography (IUCr)
Date: 28-10-2020
DOI: 10.1107/S2414314620012286
Abstract: The title pyrrolidine compound, C 18 H 23 NO 7 , is a tetra-substituted species in which the five-membered ring has a twisted conformation with the twist occurring in the C—C bond bearing the adjacent acetyloxy substituents the C m —C a —C a —C p torsion angle is −40.76 (18)° [m = methylene, a = acetyloxy and p = phenyl]. The N atom, which is sp 2 -hybridized [sum of bond angles = 359.4°], bears an ethylcarboxylate substitutent and is connected to a methylene-C atom on one side and a carbon atom bearing a 4-methoxyphenyl group on the other side. Minor disorder is noted in the ethylcarboxylate substituent as well as in one of the acetyloxy groups the major components of the disorder have site occupancies of 0.729 (9) and 0.62 (3), respectively. The most notable feature of the molecular packing is the formation of helical, supramolecular chains aligned along the b -axis direction whereby the carbonyl-O atom not involved in a disordered residue accepts C—H...O interactions from methylene-H and two-C atom separated methine-H atoms to form a six-membered {...HCCCH...O} synthon.
Publisher: International Union of Crystallography (IUCr)
Date: 31-05-2017
DOI: 10.1107/S2056989017007605
Abstract: The title organoselenium compound, C 19 H 13 ClO 3 Se {systematic name: 2-[(4-chlorophenyl)selanyl]-2 H ,3 H ,4 H ,5 H ,6 H -naphtho[1,2- b ]pyran-5,6-dione}, has the substituted 2-pyranyl ring in a half-chair conformation with the methylene-C atom bound to the methine-C atom being the flap atom. The dihedral angle between the two aromatic regions of the molecule is 9.96 (9)° and indicates a step-like conformation. An intramolecular Se...O interaction of 2.8122 (13) Å is noted. In the crystal, π–π contacts between naphthyl rings [inter-centroid distance = 3.7213 (12) Å] and between naphthyl and chlorobenzene rings [inter-centroid distance = 3.7715 (13) Å], along with C—Cl...π(chlorobenzene) contacts, lead to supramolecular layers parallel to the ab plane, which are connected into a three-dimensional architecture via methylene-C—H...O(carbonyl) interactions. The contributions of these and other weak contacts to the Hirshfeld surface is described.
Publisher: International Union of Crystallography (IUCr)
Date: 16-06-2020
DOI: 10.1107/S2056989020007914
Abstract: The title compound, C 23 H 24 N 2 O 9 , is a tetra-substituted pyrrolidine derivative with a twisted conformation, with the twist evident in the C—C bond bearing the adjacent acetyloxy substituents. These are flanked on one side by a C-bound 4-methoxyphenyl group and on the other by a methylene group. The almost sp 2 -N atom [sum of angles = 357°] bears a 4-nitrobenzyloxycarbonyl substituent. In the crystal, ring-methylene-C—H...O(acetyloxy-carbonyl) and methylene-C—H...O(carbonyl) interactions lead to supramolecular layers lying parallel to (\\overline{1}01) the layers stack without directional interactions between them. The analysis of the calculated Hirshfeld surfaces indicates the combined importance of H...H (42.3%), H...O/O...H (37.3%) and H...C/C...H (14.9%) surface contacts. Further, the interaction energies, largely dominated by the dispersive term, point to the stabilizing influence of H...H and O...O contacts in the inter-layer region.
Publisher: International Union of Crystallography (IUCr)
Date: 24-03-2017
DOI: 10.1107/S2056989017003887
Abstract: Two independent molecules comprise the asymmetric unit in the title benzoxatellurole compound, C 12 H 17 ClOTe. The molecules, with the same chirality at the methine C atom, are connected into a loosely associated dimer by Te...O interactions, leading to a {...Te—O} 2 core. The resultant C 2 ClO 2 donor set approximates a square pyramid with the lone pair of electrons projected to occupy a position trans to the n -butyl substituent. Interestingly, the Te IV atoms exhibit opposite chirality. The major difference between the independent molecules relates to the conformation of the five-membered chelate rings, which is an envelope with the O atom being the flap, in one molecule and is twisted about the O—C(methine) bond in the other. No directional intermolecular interactions are noted in the molecular packing beyond the aforementioned Te...O secondary bonding. The analysis of the Hirshfeld surface reveals the dominance of H...H contacts, i.e . contributing about 70% to the overall surface, and clearly differentiates the immediate crystalline environments of the two independent molecules in terms of both H...H and H...Cl/Cl...H contacts.
Publisher: International Union of Crystallography (IUCr)
Date: 23-07-2019
DOI: 10.1107/S2056989019010284
Abstract: The di-substituted acetylene residue in the title compound, C 11 H 11 NO 3 , is capped at either end by di-methylhydroxy and 4-nitrobenzene groups the nitro substituent is close to co-planar with the ring to which it is attached [dihedral angle = 9.4 (3)°]. The most prominent feature of the molecular packing is the formation, via hydroxy-O—H...O(hydroxy) hydrogen bonds, of hexameric clusters about a site of symmetry \\overline{3}. The aggregates are sustained by 12-membered {...OH} 6 synthons and have the shape of a flattened chair. The clusters are connected into a three-dimensional architecture by benzene-C—H...O(nitro) interactions, involving both nitro-O atoms. The aforementioned interactions are readily identified in the calculated Hirshfeld surface. Computational chemistry indicates there is a significant energy, primarily electrostatic in nature, associated with the hydroxy-O—H...O(hydroxy) hydrogen bonds. Dispersion forces are more important in the other identified but, weaker intermolecular contacts.
Publisher: American Chemical Society (ACS)
Date: 21-02-2020
Publisher: International Union of Crystallography (IUCr)
Date: 27-04-2018
DOI: 10.1107/S2056989018006072
Abstract: The title compound, C 15 H 13 ClO 2 S, comprises (4-chlorophenyl)sulfanyl, benzaldehyde and methoxy residues linked at a chiral methine-C atom (the crystal is racemic). A twist in the methine-C—C(carbonyl) bond [O—C—C—O torsion angle = 19.3 (7)°] leads to a dihedral angle of 22.2 (5)° between the benzaldehyde and methine+methoxy residues. The chlorobenzene ring is folded to lie over the O atoms, with the dihedral angle between the benzene rings being 42.9 (2)°. In the crystal, the carbonyl-O atom accepts two C—H...O interactions with methyl- and methine-C—H atoms being the donors. The result is an helical supramolecular chain aligned along the c axis chains pack with no directional interactions between them. An analysis of the Hirshfeld surface points to the important contributions of weak H...H and C...C contacts to the molecular packing.
Publisher: International Union of Crystallography (IUCr)
Date: 29-05-2020
DOI: 10.1107/S205698902000701X
Abstract: The title compound, C 13 H 19 NO 8 , is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C—C bond the C m —C a —C a —C me torsion angle is 38.26 (15)° [m = methylcarboxylate, a = acetyloxy and me = methylene]. While the N-bound ethylcarboxylate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supramolecular double-layers are formed by weak methyl- and methylene-C—H...O(carbonyl) interactions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional interactions between them. The Hirshfeld surface is dominated by H...H (55.7%) and H...C/C...H (37.0%) contacts H...H contacts are noted in the inter-double-layer region. The interaction energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal.
Location: Brazil
No related grants have been discovered for Ignez Caracelli.