Synthesis of dioxomolybdenum(VI) complexes with disubstituted salicylidene-2-furfurylimines: The crystal structure of binuclear complex [{MoO2(L5)}2(μ-O)], where L5 = 3-methoxy-5-bromosalicylidene-2-furfurylimine

Abstract

Three mononuclear and one binuclear dioxomolybdenum(VI) complexes with disubstituted Z-salicylidene-2-furfurylimines (HLⁿ) have been prepared and characterized by IR spectroscopy, namely, MoO₂Cl₂ · 2HLⁿ [Z = 3-MeO-5-Br (n = 5); 3,5-Cl₂ (n = 7); 3,5-Br₂ (n = 8)] and [{MoO₂(L⁵)}₂(μ-O)] (I). The structure of complex I has been determined by X-ray diffraction. Each of the atoms Мо1 and Мо2 has coordination number 5, which is unusual for binuclear complexes of [{MoO₂(L)}₂(μ-O)]. The coordination polyhedron of each of the atoms Мо(1) or Мо(2) may be described either as a heavily distorted trigonal bipyramid (TBP) with two oxo ligands and the atom О(L⁵) in the equatorial plane and the atoms О_br, N(L⁵) in the axial sites, or as an intermediate between a TBP and a square pyramid (SP) (τ = 0.375 for Мо(1) and 0.470 for Мо(2)).