No abstract

The crystal structures of two azobenzene derivative Schiff base metal complexes (new C44H40CuN6O2 of P-1 and known C44H38MnN6O7 of P21/c abbreviated as Cu and Mn, respectively) were (re-)determined experimentally using conventional X-ray analysis to obtain electron density using a PLATON program. Cu affords a four-coordinated square planar geometry, while Mn affords a hexa-coordinated distorted octahedral geometry whose apical sites are occupied by an acetate ion and water ligands, which are associated with hydrogen bonds. The π-π or CH-π and hydrogen bonding intermolecular interactions were found in both crystals, which were also analyzed using a Hirshfeld surface analysis program. To compare these results with experimental results, a density functional theory (DFT) calculation was also carried out based on the crystal structures to obtain calculated electron density using a conventional Gaussian program. These results revealed that the axial Mn-O coordination bonds of Mn were relatively weaker than the in-plane M-N or M-O coordination bonds.

The molecular structure of the title compound, [Cu(C12H13N2O3)(H2O)2]·[Cu(C12H13N2O3)(H2O)], consists of two different molecules in the asymmetric unit. Both of the structures consist of a tridentate ligand synthesized from L-valine and salicylaldehyde, and one water molecule or two water molecules coordinating to CuII. They have a square-planar (molecule 1) or a square-pyramidal (molecule 2) coordination geometry. In the crystal, the molecules form intra- and intermolecular O—H...O hydrogen bonds involving the coordinated water molecules and other sites. A Hirshfeld surface analysis indicated that the most important contributions to the packing are from H...H [52.9% (molecule 1) and 51.1% (molecule 2)] and H...O/ O...H [21.2% (molecule 1) and 25.8% (molecule 2)] contacts. In addition, an electrostatic potential map was also obtained from DFT calculations to support the discussion of the intermolecular interactions.

In the title complex, [Sm(NO3)3(C30H28N2O4)], the Sm atom is surrounded by ten O atoms. The (S,S)-2,2′-{[(1,2-diphenylethane-1,2-diyl)bis[(azaniumylylidene)methanylylidene]}bis(6-methoxyphenolate) ligand, obtained from o-vanillin and (1S,2S)-(−)-1,2-diphenylethylenediamine, exhibits a slightly distorted planar arrangement of the four coordinated O atoms. In the crystal, the complex shows intramolecular N—H...O hydrogen bonds and weak intermolecular C—H...O hydrogen bonds. The Hirshfeld surface analysis indicates that the most important contributions to the packing are from H...H (33.5%), O...H (34.1%) and C...H (21.7%) contacts.