Spectroscopic studies on matrix-isolated molybdenum pentachloride

Abstract

Matrix-isolation studies have been carried out on molybdenum pentachloride. In a nitrogen-matrix, prominent i.r. bands are observed at ca. 473 and 408 cm^–1, which on the basis of isotope studies are assigned as the A₁(axial) and E Mo–Cl stretching modes of monomeric MoCl₅(C_4v). Argon matrices yielded essentially the same spectroscopic features. Corresponding u.v.-visible spectra were obtained and assigned on the basis of a square-pyramidal geometry. Attempts to prepare and characterise MoCl₆ were unsuccessful.