Single-crystal and molecular structure, and polarised single-crystal electronic-absorption and electronic spin resonance spectrum of trichloro-oxobis[tris(dimethylamino)phosphine oxide]molybdenum(V)

Abstract

The single-crystal structure of [MoOCl₃{P(NMe₂)₃O}₂] has been determined by X-ray crystallography. The monoclinic unit cell of space group P2₁/n with a= 8.584(2), b= 19.774(4), c= 15.125(2)Å, and β= 99.45(2)° contains four discrete molecules. These molecules have a distorted mer-octahedral geometry [Mo–O 1.686(5), MO–Cl (mean) 2.373(17), Mo–O tras and cis to the oxo-group 2.169(4) and 2.056(5)Å respectively]. The polarised single-crystal electronic-absorption spectrum has been recorded from 10 000 to 30 000 cm^–1 at room temperature and ca. 40 K. The single-crystal e.s.r. spectra of [MoOCl₃{P(NMe₂)₃O}₂] as a pure compound and diluted in the isomorphous niobium analogue have been recorded at room temperature. The electronic structure of this d¹ system is discussed with reference to these structural and spectroscopic data.