Acta Crystallographica Section E: Crystallographic Communications最新文献

In the first title compound, C₁₆H₁₀FNO₃ (I), the dihedral angle between the 2-oxo-2H-chromene ring system and the 2-fluoro-phenyl ring is 0.73 (16)°. In the second title compound, C₁₇H₁₃NO₅S (II), the corresponding angle is 12.44 (2)°. Compound (I) features a bifurcated intra-molecular N-H⋯(O,F) hydrogen bond, whereas (II) displays an N-H⋯O hydrogen bond. In the crystal of (I), the mol-ecules are connected through pairwise C-H⋯O hydrogen bonds forming an inversion dimer generating an R ₂ ²(14) motif, whereas in (II), C-H⋯O hydrogen bonds generate an R ₂ ²(8) motif. The packing for (I) also features a C-H⋯F contact, generating an S(6) chain along [001]. The major contributions to the Hirshfeld surface of (I) are from H⋯H (30.0%), O⋯H/H⋯O (21.0%), C⋯H/H⋯C (15.9%), C⋯C (12.5%), F⋯H/H⋯F (10.8%) and O⋯C/C⋯O (5.0%) contacts while those in (II) are from H⋯H (28.0%), O⋯H/H⋯O (36.7%), C⋯H/H⋯C (19.8%), C⋯C (5.6%), and O⋯C/C⋯O (6.9%) contacts. Compound (II) demonstrated moderate to good anti-bacterial activity with MIC values of 25 µg ml^-1 against S. aureus and 15 µg ml^-1 against E. coli.

During the synthesis of the (oxalato)[5,10,15,20-tetra-kis-(4-chlor-ophen-yl)porphyrinato]magnesium(II) ([Mg(TClPP)(ox)]) complex [TClPP = 5,10,15,20-tetra-kis-(4-chloro-phen-yl)porphyrinate and ox = oxalate], the title compound, [Mg(C₄₄H₂₄ClMgN₄O₂)(H₂O)₂] ([Mg(TClPP)(H₂O)₂]), was obtained as a by-product. The di-aqua-Mg^II porphyrin complex crystallizes in the I4/m space group. In the asymmetric unit, except for two carbon atoms of the phenyl ring, all atoms lie on special positions. In the crystal, the [Mg(TClPP)(H₂O)₂] mol-ecules form layers parallel to the a axis. The crystal packing features C-H⋯π inter-actions involving the pyrrole rings and non-conventional O-H⋯Cl hydrogen bonds between the oxygen atom of the water axial ligands and the chloride of neighboring phenyl groups. Hirshfeld surface analysis indicates that inter-molecular contacts are dominated by H⋯H (50.2%), followed by H⋯Cl (21.6%) and H⋯C (21.2%) inter-actions, then by less chemically meaningful C⋯Cl (6.0%) contacts.

The title compound, C₂₁H₁₅N₃O₂, contains a nitro-aniline ring and an anthracene ring system bridged over the methyl-ene amino group. The anthracene ring system is essentially planar with an r.m.s. deviation of 0.03 (2) Å and it is oriented at a dihedral angle of 79.70 (5)° with respect to nitro-aniline ring. There is an intra-molecular N-H⋯N hydrogen bond between N atoms of nitro-aniline ring and amino group. In the crystal, N-H-O hydrogen bonds link the mol-ecules into infinite chains along the b-axis direction. π-π stacking inter-actions between the nitro-aniline rings of adjacent mol-ecules with centroid-to-centroid distance of 3.7682 (2) Å and C-H⋯π(ring) inter-actions may help to consolidate the three-dimensional architecture. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (35.5%), H⋯C/C⋯H (33.7%) and H⋯O/O⋯H (18.3%) inter-actions.

The second ortho-rhom-bic polymorph of the title compound, C₂₁H₂₁N₃O₂, (I), crystallizes in space group Pna2₁, compared to Pbca for the first ortho-rhom-bic polymorph (Iⁱ ) [Obasi et al. (2016 ▸). J. Mol. Struct. 1120, 180-186]. The difference in the structure of the two polymorphs resides in the orientation of the 4-meth-oxy moiety of the (4-meth-oxy-phen-yl)allyl-idene unit with respect to the phenyl ring to which it is attached. Compound (I) also exhibits rotational disorder of the phenyl ring of the 4-amino-anti-pyrine moiety. In the crystal of (I), the mol-ecules are linked by C-H⋯O and C-H⋯N hydrogen bonds, forming a three-dimensional network. The conformations, Hirshfeld surfaces, and two-dimensional fingerprint plots of the two polymorphs and closely related structures are compared.

The reaction of zinc iodide with 2,3-di-methyl-pyrazine (C₆H₈N₂) in ethanol leads to the formation of [ZnI₂(C₆H₈N₂)] _n (1), that according to powder X-ray diffraction was obtained as a pure phase. When the same reaction was performed in a mixture of ethanol and water as solvent, a few crystals of [ZnI₂(C₆H₈N₂)(H₂O)]·0.5C₆H₈N₂·0.5H₂O (2) were serendipitiously obtained in a mixture with compound 1 as the major phase. The asymmetric unit of 1 consists of one zinc cation, two crystallographically independent iodide anions and one 2,3-di-methyl-pyrazine ligand all of them located in general positions. In the extended structure, the Zn cations are tetra-hedrally coordinated by two iodide anions and two symmetry-related 2,3-di-methyl-pyrazine ligands and are linked by bridging 2,3-di-methyl-pyrazine ligands into helical chains that proceed along the c-axis direction in the uncommon space group P3₂. Within these chains, intra-chain C-H⋯I hydrogen bonding is observed. The asymmetric unit of 2 consists of two crystallographically independent [ZnI₂(C₆H₈N₂)(H₂O)] complexes as well as one water mol-ecule and one none-coordinating 2,3-di-methyl-pyrazine ligand. In the complexes, the Zn cations are tetra-hedrally coordinated by two iodide anions, one 2,3-di-methyl-pyrazine ligand and one water mol-ecule. These complexes are packed in such a way that cavities are formed, which are filled by water and 2,3-di-methyl-pyrazine solvate mol-ecules that are hydrogen bonded to each other.

Crystallographic workshops provide participants with a wide range of foundational knowledge and vital practical skills. They build technical and soft skills, bridge theory and practice, and provide avenues for mentorship and career growth. This short perspective article highlights the activities of recent Summer Crystallography Institutes held at Whitworth University and provides additional discussion of key workshop components, including philosophy, objectives, strategies, planning, timeline, schedule, and funding.