Molecular and Inner Complex Compounds of Dioxomolybdenum(VI) with Disubstituted Salicydenealcoholimines: Crystal Structure of 1 : 1 Dioxo(3,5-Dibromosalicylidenemonoethanoliminato)molybdenum(VI) Solvate with Methanol [MoO2(L1) · MeOH] (L1 = C9H7Br2NO2)

Abstract

Complexes of dioxomolybdenum(VI) of the molecular (МоО₂Сl₂ · 2H₂L) and inner complex ([MoO₂L · Solv]) types are synthesized (H₂L are azomethines, derivatives of disubstituted R¹,R²-salicylaldehydes (R¹, R² = 3.5-Вr₂; R¹ = 3-МеО, R² = 5-Вr) and monoethanolamine; Solv is a methanol, dimethylformamide, pyridine, or α-picoline molecule). The cis-octahedral structure of the complexes is concluded on the basis of the IR spectroscopic data. In the molecular compounds, the ligands are coordinated via the O atom of the carbonyl group of the H₂L tautomeric form. In the inner complex compounds, the ligands are coordinated in the deprotonated benzoid form. The structure of [MoO₂(L¹) · МеОН] (I) (where L¹ is C₉H₇Br₂NO₂) is determined by X-ray diffraction analysis (СIF file CCDC no. 1898088). In the mononuclear molecule of compound I, the Mo atom has the octahedral coordination by two oxo ligands, two oxygen atoms, the nitrogen atom of the tridentate bis(chelate) two-charge ligand (L¹)^2–, and the O atom of the methanol molecule. The neutral N(1) and O(1) atoms of the L¹ and МеОН ligands, respectively, are arranged in the trans positions to the O(oxo) ligands. The Mo–N(1) (2.265 Å) and Мо–О(1) (2.372 Å) bonds are substantially elongated due to the structural manifestation of the trans effect of the multiply bonded oxo ligands. The intermolecular hydrogen bonds (МеОН)О–Н···О(oxo) join the molecules into supramolecular 1D chains.