Preparation, properties and crystal structures of nickel(II) complexes with acyclic schiff bases derived from 2,6-diformyl-4-chlorophenol and 1,5-diamino-3-thiapentane or 3,3?-diamino-N-methyl-dipropylamine

Nickel(II) complexes with the compartmental Schiff bases derived from 2,6-diformyl-4-chlorophenol and 1,5-diamino-3-thiapentane (H2L1) or 3,3?-diamino-N-methyl-dipropylamine (H2L2) were synthesized, and the crystal structures of [Ni(L1)- (py)2] and [Ni(L2)(dmf)]·H20 were determined by X-ray crystallography. Ni(L1)(py)2 is monoclinic, space group C2/c, with a= 18.457(6), b = 11.116(7), c= 16.098(6) Å, and ? = 115.79(5)°; Dc = 1.49 g cm-3 for Z = 4. The structure was refined to the final R of 6.9%. The molecule has C2 symmetry. The nickel atom is six-coordinated octahedral. Selected bond lengths are: NiO 2.04(1) Å, NiN (L1) 2.08(1) Å, NiN(py) 2.17(1) Å. [Ni(L2)(dmf)]·H2O is monoclinic, space group P21/n, with a = 17.329(6), b = 13.322(7), c = 12.476(7) Å and ? = 95.43(5)°; Dc = 1.45 g cm-3 for Z = 4. The structure was refined to the final R of 5.1%. The nickel atom is bonded in the octahedral geometry to the bianionic pentadentate ligand L2 and to one molecule of dimethylformamide. Selected bond lengths are: NiO (charged) 2.063(3) Å (mean value), NiO (neutral) 2.120(3) Å, NiN (planar) 2.050(3) Å (mean value), NiN (tetrahedral) 2.177(3) Å.