Effect of isocyanide ligand on the interaction of triosmium isocyanide complexes with amines
作者:Kuang Lieh Lu、Chi Jen Chen、Yen Wen Lin、Han Mou Gau、Fung E. Hong、Yuh Sheng Wen
DOI:10.1021/om00030a031
日期:1993.6
The interaction of the osmium isocyanide complexes Os3(CO)11(CNR) (1) with primary amines leads initially to the formation of the carboxamido complexes Os3(CO)10(mu2-CONHR')(mu2-C=NHR) (2) with a bridging aminocarbyne. The latter react with excess corresponding amines to yield Os3(CO)9(NH2R')(mu2-CONHR')(mu2-C=NHR) (3). Bubbling CO through the solution of 3 regenerates 2. Treatment of complex 2 with PPh3 affords Os3(CO)9(PPh3)(mu2-CONHR')(mu2-C=NHR) (5). Complex 3, when passed through silica gel, results in structure transformation to the hydrido complexes (mu-H)Os3(CO)9(mu2-CONHR')(CNR) (4) with the regeneration of the isocyanide ligand. Treatment of 3 with CH3CO2H or CF3CO2H also results in the formation of 4. In contrast, complex 2 or complex 5 remains unchanged when passed through silica gel. The transformation of the isocyanide ligand with the cleavage and formation of an Os-Os bond may play an important role in mediating the reactivity of the osmium cluster. The structures of Os3(CO)10(mu2-CONHPr(i))(mu2-C=NHCH2Ph) (2c), Os3(CO)9(NH2Pr(i))(mu2-CONHPr(i))(mu2-C=NBPh) (3a), and (mu-H)Os3(CO)9(mu2-CONHPr(i))(CNCH2Ph) (4c) have been determined by X-ray crystallography. Crystal data are as follows. 2c: Pbca; a = 11.9975(14) angstrom, b = 17.797(4) angstrom, c = 25.819(3) angstrom; V = 5512.9(14) angstrom3, Z = 8; R = 5.6%, R(w) = 5.9%. 3a: P1BAR; a = 8.7042(13) angstrom, b = 13.1002(20) angstrom, c = 13.546(4) angstrom, alpha = 93.456(17)-degrees; beta = 89.905(16)-degrees, gamma = 106.393(13)-degrees; V = 1478.9(5) angstrom3, z = 2; R = 3.8%, R(w) = 4.5%. 4c: P2(1)/n; a = 9.3811(15) angstrom, b = 10.0523(14) angstrom, c 28.265(17) angstrom; beta = 91.81(3)-degrees; V = 2664.1(17) angstrom3, z = 4; R = 3.6%, R(w) = 4.2%.