Preparation, spectroscopic and magnetic characterization of a new series of two-dimensional transition metal compounds. The x-ray structure of poly-bis(thiocyanato- N)-bis-μ- [1,2,4] triazolo [1,5- a] pyrimidine- N1, N3)iron(II)

Abstract

The synthesis of a series of polynuclear compounds of general formula [M(tp) 2(NCS) 2] n (M = Mn, Fe, Co, Ni and tp = [1,2,4]triazolo[1,5− a]pyrimidine, C 5H 4N 4) is described. The compounds are X-ray and IR isostructural and were further characterized by ligand field and magnetic susceptibility measurements. The structure of the iron compound was determined by X-ray diffraction methods. It crystallizes in the orthorhombic space group Aba2, with a=8.028(2), b=20.422(6), c=10.129(5) Å. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrtx least-squares to R = 0.040 for 706 observed reflections. The structure consists of octahedral iron complexes in which the metal atom is coordinated by two nitrogen atoms from two monodentate NCS groups and by four nitrogen atoms from four symmetry-related tp molecules; each organic ligand bridges two metal atoms through both non-bridgehead triazole nitrogen atoms, joining the octahedral complexes in a layered system where the Fe···Fe distance is 6.49 Å.