tert-Butyl-substituted vanadocene, (C5H4CMe3)2V: a precursor for MOCVD of pure vanadium carbide

Abstract

tert-Butyl-substituted vanadocene, (C₅H₄CMe₃)₂V (1), is used as a precursor in the CVD preparation (740 °C under hydrogen at atmospheric pressure on steel substrates) of crystalline VC_0.88 thin films, characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis with wavelength dispersive spectroscopy (EPMA–WDS), which are not contaminated by graphitic carbon or oxygen. 1 was obtained by reaction of (C₅H₄CMe₃)Na with [(V₂Cl₃)(THF)₆]₂(Zn₂Cl₆) and characterized by X-ray crystal structure analysis [monoclinic, P2₁/n; a= 6.164(1), b= 11.263(2), c= 11.842(2)Å, β= 96.31(2)°; V= 817.2(7)ų; Z= 2]. A possible mechanism for the deposition of VC films from 1 is proposed.