The crystal and molecular structure of thiocyanatocopper(II) complexes with 3-methylpyridine and 3,4-dimethylpyridine

Abstract

Crystals of the complexes [Cu(3,4-diMepy)3(NCS)2] (I) and [Cu(3-Mepy)3(NCS)2] (II) (Me = methyl, py = pyridine) possess the monoclinic symmetry, Pc, with the unit cell parameters of I and II: a = 0.9825(7) and 0.9027(7) nm, b = 0.9740(7) and 0.9021(7) nm, c = 1.4130(60) and 1.4958(50) nm, β = 108.8(4)° and 114.08(4)°, Z = 2 in both cases, d0 = 1.32.103 and 1.37.103 kg m-3, and dc = 1.30.103 and 1.37.103 kg m-3, respectively. The central atom in the complexes exhibits tetragonal pyramidal coordination. The thiocyanate ligands are coordinated by the nitrogen atoms in the equatorial as well as axial positions of the coordination polyhedron. The three heterocyclic ligands are bonded in the equatorial plane. The arrangement of the ligands and the interatomic distances are the same in the two complexes. The crystals were prepared by reacting an ammoniacal solution of CuSO4 with an ethanolic solution of the heterocyclic ligand L and an aqueous solution of NH4NCS so that the c(Cu):c(NH3):c(L):c(NCS) ratio was 2:8:5:4.