Transition metals and oxide(s) esp. rhenium and osmium - obtd. by thermal, photochemical or plasma-induced decomposition of corresp. organo-metal oxide(s) e.g. methyl-rhenium tri:oxide

摘要

Prodn. of transition metals of Gps. VIIB and VIIIB (except Fe, Co, and Ni) and oxides comprises decomspn. of the corresp. volatile organo-transition metal oxides of formula RaMebOc (I); (where R = opt. substd. or unsatd. 1-12C alkyl, 3-12C mono or poly-cyclic hydrocarbyl, opt. substd. 6-10C aryl or an aromatic pi-bonded ligand with 5-8C atoms in the ring; Me = transition metal; O = oxygen; a = 1-12; b = 1-3; c = 1-8). The process pref. comprises gas-phase thermal decompsn. at 30-1500 (pref. 60-600) deg.C photochemical decompsn. with light of wavelength of 100-1000 (pref. 150-600) nm at -50 to 150 (pref. 0-50) deg.C or plasma-chemical decompsn. Decompsn. is carried out in vacuo (down to 10 power -5 Torr), pref. in the presence of an inert carrier gas, esp. argon, under reducing or oxidising conditions, pref. obtd. by addn. of hydrogen or oxygen respectively. The prods. are obtd. as layers and/or films by performing the reaction in the presence of substrates. (I) is used in polymeric form and pref. decomposed photochemically in the presence of water. Pref. (I) are Re and Os cpds. (e.g. methyl-rhenium trioxide), prepd. e.g. as described in J. Organometal Chem. 272, 351 (1989), Angew. Chem. 103, 100 (1991) Polyhedron 6, 1165 (1987), Angew. CHem, 102, 1460, (1990). Suitable substrates for coating are glass, metal, ceramic, PE, PTFE, etc. USE/ADVANTAGE - Simple process is for the prodn. of transition metals and oxides as above, in high yield and high purity, from relatively stable precursors (II). Deposition (thermal, photo or plasma decompsn). can be varied depending on the properties of (II), under process conditions which can be varied considerably by the nature of R and which can be altered to obtain prods. with the required physical properties and oxygen content. The prods. are obtd. in the form of thin layers if required (contrast other processes), e.g. for electrically conductive coatings, corrosion-proof coatings etc.