REACTIONS OF PERFLUOROALKYL-SUBSTITUTED PHOSPHINES WITH OSMIUM CARBONYL CLUSTERS - CRYSTAL-STRUCTURES OF BRIDGED, LINKED AND SUBSTITUTED DERIVATIVES

The secondary phosphine (CF3)2C(OH)PH(CF3) has been shown from H-1 and F-19 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(mu-H)(CO)10{mu-PH(CF3)}] 1 and the linked cluster [{Os3(mu-H)(CO)11}{mu-PH(CF3)}{Os3(CO)11}] 2. However, its reaction with [Os3(CO)10(MeCN)2] afforded the novel molecule [Os3(mu-H)(CO)9{mu-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), 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(mu-H)(CO)10(mu-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.