Crystal and molecular structure of CoCl2(L)(1/2 acetone) where L is =[8-methoxy-3-methyl-6-nitro-2H-1-benzopyran-2-spiro-2′-(3-methyl-benzothiazoline)

Abstract

The molecular structure of the title compound has been determined by X-ray analysis. The structure was solved by the multisolution technique and the atomic parameters refined by full-matrix, least-squares calculations, to an R value of 0.09 for 2 544 observed reflexions. There are two molecules in the asymmetric unit: one in the form of dimer (A) and the other in the form of monomeride (B). In both molecules the co-ordination sphere of the cobalt atom is composed of oxygen and chlorine atoms. The geometry of the co-ordination polyhedra is determined from the mean angular and dihedral angle deviation from idealized trigonal bipyramidal and tetragonal pyramidal models. It can be described as a more [in (A)] or less [in (B)] distorted trigonal bipyramid. The geometry of the ligand could be associated with that of the hypothetical intermediate of the spiropyran ⇆ merocyanine photoconversion process. In the crystal lattice, molecular stacks of monomeric (along b) and dimeric complexes (along a) are formed and cross-linked through short van der Waals contacts. I.r. and solid-state reflectance spectra are given.