Crystal and molecular structure of trichloro-oxobis(triphenylphosphine oxide)tungsten(V), (1). Single-crystal electron spin resonance spectra of (1) and tetraphenylarsonium aquatetrachloro-oxotungstate(V) and electronic structures of these and some related molybdenum(V) compounds

Abstract

The crystal structure of (1) has been determined by X-ray crystallographic methods. The compound crystallises in the monoclinic space group C2/c with a= 14.002(6), b= 13.059(7), c= 19.158(8)Å, β= 96.00(3)°, and Z= 4. The [WOCl₃(PPh₃O)₂] molecule is disordered over two orientations in the crystal and possesses a crystallographically imposed C₂ axis passing through the W atom. The disordered atoms are Cl(2) and O(2). Molecular dimensions are W–Cl(1), 2.369(4); W–O(1), 2.088(11); W–Cl(2), 2.242(10); and W–O(2), 2.053(22)Å. Single-crystal e.s.r. spectra of (1) diluted in the niobium analogue gave g₁= 1.739 ± 0.002, g₂= 1.763 ± 0.002, and g₃= 1.770 ± 0.002, whilst a similar study on [AsPh₄][WOCl₄(OH₂)] gave g_∥= 1.806 ± 0.001 and g_⊥= 1.765 ± 0.001. The e.s.r. data for [WOCl₃(PPh₃O)₂], [MoOCl₃(PPh₃O)₂], and [MoOCl₃{P(NMe₂)₃O}₂] are discussed in terms of an angular-overlap model for their electronic structures.