Browsing by Author "Wardell, James L."
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- Crystal structures and Hirshfeld surface analyses of (E)-N′-benzylidene-2-oxo-2H-chromene-3-carbohydrazide and the disordered hemi-DMSO solvate of (E)-2-oxo-N′-(3,4,5-trimethoxybenzylidene)-2H-chromene-3-carbohydrazide: lattice energy and intermolecular interaction energy calculations for the formerPublication . Gomes, Ligia R.; Low, John Nicolson; Wardell, James L.; Capelini, Camiola; Câmara, Vitoria R.F.; Silva, Edson F. da; Carvalho, Samir A.The crystal structures of the disordered hemi-DMSO solvate of (E)-2-oxo-N'-(3,4,5-tri-meth-oxy-benzyl-idene)-2H-chromene-3-carbohydrazide, C20H18N2O6·0.5C2H6OS, and (E)-N'-benzyl-idene-2-oxo-2H-chromene-3-carbohydrazide, C17H12N2O3 (4: R = C6H5), are discussed. The non-hydrogen atoms in compound [4: R = (3,4,5-MeO)3C6H2)] exhibit a distinct curvature, while those in compound, (4: R = C6H5), are essential coplanar. In (4: R = C6H5), C-H⋯O and π-π intra-molecular inter-actions combine to form a three-dimensional array. A three-dimensional array is also found for the hemi-DMSO solvate of [4: R = (3,4,5-MeO)3C6H2], in which the mol-ecules of coumarin are linked by C-H⋯O and C-H⋯π inter-actions, and form tubes into which the DMSO mol-ecules are cocooned. Hirshfeld surface analyses of both compounds are reported, as are the lattice energy and inter-molecular inter-action energy calculations of compound (4: R = C6H5).
- Crystal structures and Hirshfeld surfaces of four methoxybenzaldehyde oxime derivatives, 2-MeO-XC6H3C=NOH (X = H and 2-, 3- and 4-MeO): different conformations and hydrogen-bonding patternsPublication . Gomes, Ligia R.; Souza, Marcus V. N. de; Da Costa, Cristiane F.; Wardell, James L.; Low, John NicolsonThe crystal structures of four (E)-meth-oxy-benzaldehyde oxime derivatives, namely (2-meth-oxy-benzaldehyde oxime, 1, 2,3-di-meth-oxy-benzaldehyde oxime, 2, 4-di-meth-oxy-benzaldehyde oxime, 3, and 2,5-di-meth-oxy-benzaldehyde oxime, 4, are discussed. The arrangements of the 2-meth-oxy group and the H atom of the oxime unit are s-cis in compounds 1-3, but in both independent mol-ecules of compound 4, the arrangements are s-trans. There is also a difference in the conformation of the two mol-ecules in 4, involving the orientations of the 2- and 5-meth-oxy groups. The primary inter-molecular O-H(oxime)⋯O(hy-droxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O-H(oxime)⋯O(hy-droxy) hydrogen bonds generate symmetric R22(6) dimers. A more complex dimer is generated in 4 from the O-H(oxime)⋯O(hy-droxy) and C-H(2-meth-oxy)⋯O(hy-droxy) hydrogen bonds. In all cases, further inter-actions, C-H⋯O and C-H⋯π or π-π, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.
- Different classical hydrogen-bonding patterns in three salicylaldoxime derivatives, 2-HO-4-XC6H3C=NOH (X = Me, OH and MeO)Publication . Gomes, Ligia Rebelo; Souza, Marcus V. N. de; Da Costa, Cristiane F.; Wardell, James L.; Low, John NicolsonThe crystal structures of three salicyaldoxime compounds, namely 2-hy-droxy-4-methyl-benzaldehyde oxime, C8H9NO2, 1, 2,4-di-hydroxy-benzaldehyde oxime, C7H7NO3, 2, and 2-hy-droxy-4-meth-oxy-benzaldehyde oxime, C8H9NO3, 3, are discussed. In each compound, the hydroxyl groups are essentially coplanar with their attached phenyl group. The inter-planar angles between the C=N-O moieties of the oxime unit and their attached phenyl rings are 0.08 (9), 1.08 (15) and 6.65 (15)° in 1, 2 and 3, respectively. In all three mol-ecules, the 2-hy-droxy group forms an intra-molecular O-H⋯N(oxime) hydrogen bond. In compound (1), inter-molecular O-H(oxime)⋯O(hydrox-yl) hydrogen bonds generate R22(14) dimers, related by inversion centres. In compound 2, inter-molecular O-H(oxime)⋯O(4-hy-droxy) hydrogen bonds generate C9 chains along the b-axis direction, while O-H(4-hydrox-yl)⋯O(2-hydrox-yl) inter-actions form zigzag C6 spiral chains along the c-axis direction, generated by a screw axis at 1, y, 1/4: the combination of the two chains provides a bimolecular sheet running parallel to the b axis, which lies between 0-1/2 c and 1/2-1 c. In compound 3, similar C9 chains, along the b-axis direction are generated by O-H(oxime)⋯O(4-meth-oxy) hydrogen bonds. Further weaker, C-H⋯π (in 1), π-π (in 2) and both C-H⋯π and π-π inter-actions (in 3) further cement the three-dimensional structures. Hirshfeld surface and fingerprint analyses are discussed.
- Structural study of N-(1,3-Benzothiazol-2-yl)-4-Halobenzenesulfonylhydrazides: hirshfeld surface analysis and PIXEL calculationsPublication . Gomes, Lígia Rebelo; Low, John N.; Pinheiro, Alessandra C.; Wardell, James L.Hydrazonylsulfones such as Bt-NHNHSO2R and their iminotautomers have been studied as optical materials and for their biological potential. In this work, a structural study has been carried out on N-(1,3-benzothiazol-2-yl)-4-(halogenobenzenesulfonyl)-hydrazides (1: X = F, Cl, Br). For (1: X = F), single-crystal X-ray diffraction, Hirshfeld surface analysis, and PIXEL calculations were conducted, while in (1: X = Cl) and (1: X = Br), only single-crystal X-ray diffraction studies were successfully conducted due to the disordering of the solvent. Each compound crystallises with two independent but similar amino tautomers in the asymmetric units: compound (1: X = F) crystallises in the monoclinic P21/c, and the isostructural pair (X: 1 = Cl and Br) crystallises in the tetragonal P-421c space group. In the most stable motif of the supramolecular arrangement, the molecules of the asymmetric unit are connected by classical N–H(hydrazinyl)•••N(thiazoyl) hydrogen bonds and several face-to-face, offset π•••π interactions. This motif has a very powerful influence on the crystal structure due to its direct links with the other weaker motifs. Other significant intermolecular interactions found in the structure include N–H(hydrazonyl)•••O(sulfonate) bonds. Analogous intermolecular interactions were found in similar compounds, leading to the conclusion that those interactions are the most important instabilizing the solid state of hydrazonylsulfones.