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The atomic layer deposition of copper metal thin films was achieved using a three precursor sequence entailing Cu(OCHMeCH2NMe2)2, formic acid, and hydrazine. A constant growth rate of 0.47−0.50 Å/cycle was observed at growth temperatures between 100 and 170 °C. The resulting films are high purity and have low resistivities.

The reaction of dichloro(pentamethylcyclopentadienyl)ruthenium(III) oligomer with alkali metal salts of a variety of cyclopentadienyl derivatives provided a convenient synthetic approach to unsymmetrical ruthenocenes. In addition, reaction of dichloro(pentamethylcyclopentadienyl)ruthenium(III) oligomer with diazotetrachlorocyclopentadiene gave ($-pentamethylcyclopentadienyl)(q5-pentachlor~yclo~ntadienyl)ruthenium(II). With use of the general approaches outlined, ruthenocenes were prepared where one-half of the sandwich was the pentamethylcyclopentadienyl group and the other was (a) cyclopentadienyl, (b) indenyl, (c) fluorenyl, (d) acetylcyclopentadienyl, or (e) pentachlorocyclopentadienyl. Electrochemical studies and XPS studies were carried out on all five unsymmetrical ruthenocenes and on decamethylruthenocene and ruthenocene in order to determine the electronic effects of the various ligands. These studies showed that the order of decreasing electron-donating power was fluorenyl, pentamethylcyclopentadienyl, indenyl, cyclopentadienyl, acetylcyclopentadienyl, and pentachlorocyclopentadienyl. Single-crystal X-ray analyses were carried out on (~5-pentamethylcyclopentadienyl)(~5-pentachlorocyclopentadienyl)ruthenium(II), (~5-pentamethylcyclopentadienyl)(~5-indenyl)ruthenium(II), and ($-pentamethylcyclo- pentadienyl)(~5-fluorenyl)ruthenium(II). (.tl5-Pentamethylcyclopentadienyl)(~5-pentachlorocyclopentadienyl)ruthenium(II)crystallized in the orthorhombic space group Pnma with a = 8.531 (2) A, 6 = 14.208 (4) A, c = 14.541 (2) A. The calculated density was 1.785 g/cm3 for four molecules in the unit cell at room temperature. The unweighted R factor for the structure was 0.041, and data were collected with use of a variable-rate 0-20 scan technique and graphite monochromatized Mo K a radiation. After Lorentz-polarization corrections, 1206 reflections with 20 = 0-52' were observed for [FO2 t 2u(F,Z)]. (q5-Pentamethylcyclopentadienyl)(~5-indenyl)ruthenium(II) crystallized in the monoclinic space group P2,/n with a = 13.029 (16) A, 6 = 12.789 (13) A, c = 9.546 (7) A, fl = 95.31 (8)'. The calculated density was 1.473 g/cm3 for four molecules in the unit cell at room temperature. The unweighted R factor for the structure was 0.037, and the data were collected by using a variable-rate w 2 0 scan technique and graphite monochromatized Mo K a radiation. After Lorentz-polarization corrections, 1861 reflections with 20 = ( 3-52' were observed for [ F z 2 2u(F:)]. (~s-Pentamethylcyclopentadienyl)(~5-fluorenyl)ruthenium(II) crystallized in the monoclinic space group P 2 , / a with a = 22.923 ( 8 ) A, 6 = 8.813 ( 5 ) A, c = 19.149 (8) A, fl = 107.40(3)'. The calculated density was 1.445 g/cm3 for eight molecules in the unit cell at room temperature. The unweighted R factor for the structure was 0.060, and the data were collected by using a variable-rate w-20 scan technique and graphite monochromatized Mo K a radiation. After Lorentz-polarization corrections, 58 1 1 reflections with 20 = 0-5 1 ' were observed for [F,2 2 2 u (~, 2 ) ...