Crystal and molecular structure of [SnLCl3]. The single-crystal electron paramagnetic resonance spectra of [MoE(L)Cl2] and [MoO(L)(NCS)2] diluted in [SnLCl3][E = O or S; L = tris(3,5-dimethylpyrazolyl)hydroborate

Abstract

The crystal structure of [SnLCl3] has been determined and shown to consist of discrete distorted fac-octahedral molecules [L = tris(3,5-dimethylpyrazolyl)hydroborate]. The single-crystal EPR spectra, at room temperature and Q-band frequencies, of [MoE(L)Cl2] and [MoO(L)(NCS)2], E = O or S, diluted in the structurally similar [SnLCl3] have been recorded. The data from the different possible diluent sites in [SnLCl3] are consistent with exact, or nearly exact, monoclinic EPR symmetry for each of the molybdenum compounds which involves a rotation of the g and A tensors about an axis perpendicular to the mirror plane in each molecule. The angles of rotation are in the range 30–38° and are in good agreement with those obtained via simulation of the frozen-solution X-band EPR spectra of the compounds. The relationships between the g and A tensors, the molecular geometries, and the electronic structures are discussed.