Spectral properties and crystal structure of bis(μ-thiocyanato- N,S)bis-(thiocyanato- N)tetrakis(5,7-dimethyl[1,2,4]triazolo[1,5-α]pyrimidine- N3)dicopper(II) and of tetrakis(5,7-dimethyl[1,2,4]triazolo[1,5-α]pyrimidine- N3)platinum(II) hexa(thiocyanato- S)platinate(IV)

Abstract

The preparation, spectroscopic studies and the crystal structure of Cu(dmtp) 2(NCS) 2 ( I) and Pt(dmtp) 4Pt(SCN) 6 ( II) (dmtp stands for the 5,7-dimethyl[1,2,4]triazolo[1,5- a] pyrimidine ligand) are described. Crystals of I are monoclinic, space group C2/ c, with a = 19.088(7), b = 11.516(8), c = 20.118(7) Å, β = 104.51(4)°, Z = 28; crystals of II are monoclinic, space group P2 1/ n, with a = 16.914(8), b = 11.474(9), c = 11.893(7) Å, β = 91.52(4)°, Z = 2. The structures of I and II have been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.044 for I and 0.051 for II. The structure of I consists of centrosymmetric dimers [Cu(dmtp) 2(NCS) 2] 2, in which the copper atoms, bridged by two thiocyanate groups, are in a square pyramidal arrangement involving two isothiocyanate nitrogen atoms and two triazole nitrogen atoms from two dmtp ligands in the basal plane and a thiocyanate sulphur atom from the centrosymmetric complex in the apical position. The structure of II consists of square planar [Pt(dmtp) 2] 2+ cations, in which the platinum atom is bound to four triazole nitrogen atoms from dmtp ligands and of octahedral [Pt(SCN) 6] 2− anions with the metal bound to sulphur atoms of thiocyanate anions.