BARIUM AND TITANIUM ARYL OXIDES AS PRECURSORS FOR THE PREPARATION OF THIN-FILM OXIDES - THE EFFECT OF BOMBARDMENT BY O-2(+)

A set of barium aryl oxides of composition [Ba(OC(6)H(2)Bu(2)(t)-2,6-X -4)(2)(thf)(n)] (X = H 1, Me 2, OMe 3 or Bu(t) 4; thf = tetrahydrofura n) has been prepared together with the related adducts [Ba(OC(6)H(2)Bu (2)(t) - 2.6-X-4)(2){P(NMe(2))(3)O}(2)] (X = H 5 or Me 6), which can b e obtained by treating compounds 1 and 2 with neat P(NMe(2))(3)O respe ctively. X-Ray studies showed that 6 has a distorted-tetrahedral struc ture, with the two Ba-O bonds to the aryl oxide ligands somewhat short er than those to the P(NMe(2))(3)O groups [2.414(8) vs. 2.579(8) Angst rom]. Samples of complex 4 and [Ti(OC6H3Pr2i-2,6)(4)], respectively, a nd a third homogeneous sample obtained by mixing equimolar amounts of these have been subjected to bombardment by Ar+ and O-2(+) ions of rel atively low energy (3.5 keV) and the ensuing transformation investigat ed by X-ray photoelectron spectroscopy. No significant variation of th e C/M ratio was observed when employing Ar+ ions, but O-2(+) produced a remarkable decrease in the carbon content which leads eventually to the formation of inorganic compounds, BaCO3, TiO2 and BaTiO3, respecti vely, for the three samples. Action of oxygen plasma on the titanium a ryl oxide did not result in a marked decrease in the C/M ratio, but it produced instead high concentrations of carbon- and oxygen-containing species.