Unusual cocrystals made of a Schiff base metal complex and an organic molecule – Close-packing vs. hydrogen bond interactions

Six-coordinated nickel(II) complexes with benzothiadiazole Schiff-base ligands: synthesis, crystal structure, magnetic and HFEPR study

Two new nickel(II) complexes, namely Ni(L1)2 (1) and Ni(L2)2·CH2Cl2(2) were obtained by reacting nickel(II) acetate tetrahydrate with the benzothiadiazole Schiff base ligands HL1 = 2-[4-(2,1,3-benzothiadiazole)imino]methyl-phenol or HL2 = 2-[(2,1,3-benzothiadiazol-4-ylimino)methyl]-6-methoxyphenol in the presence of Et3N. The tridentate NNO chelate ligands induce a distorted octahedral environment around the nickel(II) ions. Single crystal X-ray diffraction analysis reveals elongated Ni-N bonds with the nitrogen atom of the benzothiadiazole ring in both complexes. Intermolecular hydrogen bonds and π-π stacking interactions create two-dimensional and three-dimensional supramolecular arrays, respectively, for complexes 1 and 2. Magnetic susceptibility and high-field electron paramagnetic resonance measurements show the presence of significant magnetic anisotropy, with an axial distortion parameter D of -8--10 cm-1.

3d transition metal complexes with a julolidine–quinoline based ligand: structures, spectroscopy and optical properties

Five new complexes of a julolidine–quinoline based ligand with 3d transition metals have been synthesised and structurally characterised.

Crystal structure of bis-(2-{[(pyridin-2-yl)methyl-idene]amino}-benzoato-κ(3) N,N',O)cobalt(II) N,N-di-methyl-formamide sesquisolvate

The coordination geometry around the central Co^II ion is unexpectedly different from that for the co-crystal of the title mol­ecule with anthranilic acid.

The title compound, [Co(C₁₃H₉N₂O₂)₂]·1.5C₃H₇NO, is formed as a neutral Co^II complex with di­methyl­formamide (DMF) solvent mol­ecules. The Co^II atom has a distorted O₂N₄ octa­hedral coordination sphere defined by two tridentate anionic Schiff base ligands with the O atoms being cis. The coordination sphere around the Co^II atom is geometrically different from that reported for the co-crystal [Co(C₁₃H₉N₂O₂)₂]·AA·H₂O (AA is anthranilic acid). One of the DMF solvent mol­ecules was modelled as being disordered about a crystallographic inversion centre with half-occupancy. The crystal structure is made up from alternating layers of complex mol­ecules and DMF mol­ecules parallel to (010). C—H⋯O hydrogen-bonding inter­actions between the complex mol­ecules and the solvent mol­ecules consolidate the crystal packing.