Reactions of perfluoroalkyl-substituted phosphines with osmium carbonyl clusters: Crystal structures of bridged, linked and substituted derivatives

Abstract

The secondary phosphine (CF3)2C(OH)PH(CF3) has been shown from 1H and 19F NMR and single-crystal X-ray diffraction studies to undergo P-C bond cleavage upon reaction with [Os3(CO)11(MeCN)] to afford the phosphido-bridged cluster [Os3(μ-H)(CO)10{μ-PH(CF3)}] 1 and the linked cluster [{Os3(μ-H)(CO)11}{μ-PH(CF3)}{Os 3(CO)11}] 2. However, its reaction with [Os3(CO)10(MeCN)2] afforded the novel molecule [Os3(μ-H)(CO)9{μ-HN=C(Me)P(CF3)}] 3 the molecular structure of which has also been established. Compound 1 was also obtained from the reaction of (CF3)2C(OH)PH(CF3) or PH(CF3)2 with the anionic cluster [Os3H(CO)11]-. Furthermore the primary phosphines (CF3)2C(OH)PH2 and PH2(CF3) display similar P-C bond cleavage upon reactions with [Os3H(CO)11]- to afford the phosphido-bridged cluster [Os3(μ-H)(CO)10(μ-PH2)]. On the other hand, (CF3)2C(OH)PH2 gave simple substitution products upon reactions with [Os3(CO)10(MeCN)2] and [Os3(CO)11(MeCN)], as has been found for the tertiary phosphine P(CF3)3. Compound 2 represents the first example of two triosmium triangles linked by a terminally co-ordinated PR2 group.