STRUCTURAL AND 2-DIMENSIONAL P-31 NUCLEAR-MAGNETIC-RESONANCE STUDIES OF DERIVATIVES FROM (RP)(5) (R=ET OR PH) AND ACTIVATED TRIOSMIUM CLUSTERS [OS-3(CO)(10)X(2)] (X=MU-H OR NCME)

The reaction of the cyclophosphane (EtP)(5) with the activated triosmi um cluster [Os-3(mu-H)(2)(CO)(10)] at 80 degrees C gave [Os-3(mu-H)(CO )(8)(mu-eta(3)-P(5)Et(5)H)] 1 and [Os-3(CO)(10){1,3-(PEt)(5)}] 2. The compound (PhP)(5) reacted with [Os-3(mu-H)(2)(CO)(10)] at room tempera ture to give [Os-3(mu-H)(CO)(8)(mu-eta(3)-P(5)Ph(5)H)] 3. Treatment of (EtP)(5) with [Os-3(CO)(10)(NCMe)(2)] at room temperature afforded [O s-3(CO)(10){1,2-(PEt)(5)}] 4, while the reaction at 80 degrees C yield ed only 2. All the reaction products have been characterized by elemen tal analysis and IR, H-1 and P-31 NMR spectroscopy. The solid-state st ructures of compounds 1, 2 and 4 established by single-crystal X-ray d iffraction showed that the phosphorus ring in ! has undergone one P-P bond cleavage while those in 2 and 3 are intact. The solution structur e of 3 has been fully characterized by two-dimensional P-31 NMR spectr oscopy.