Fluorous triosmium clusters. Preparation, properties, and reactivity of Os 3(CO) 11{P(CH 2CH 2(CF 2) 5CF 3) 3} and Os 3(CO) 10{P(CH 2CH 2(CF 2) 5CF 3) 3} 2. Crystal structure of Os 3(CO) 9(PPh 3) 2{P(CH 2CH 2(CF 2) 5CF 3) 3}. Ring opening metathesis polymerization of norbornene by (μ-H) 2Os 3(CO) 9{P(C 6H 4-4-CH 2CH 2(CF 2) 7CF 3)

Abstract

Several fluorous phosphine ligand triosmium carbonyl cluster derivatives, e.g., Os 3(CO) 11{P(CH 2CH 2(CF 2) 5CF 3) 3} ( 1) and Os 3(CO) 10{P(CH 2CH 2(CF 2) 5CF 3) 3} 2 ( 2) have been synthesized in order to assess their properties in fluorocarbon, or fluorous, phases. Cluster 1 reacts with PPh 3 above 100 °C to substitute one or two carbonyl ligands and provide the mixed ligand derivatives Os 3(CO) 10(PPh 3){P(CH 2CH 2(CF 2) 5CF 3) 3}, ( 3) and Os 3(CO) 9(PPh 3) 2{P(CH 2CH 2(CF 2) 5CF 3) 3}, ( 4). The crystal structure of 4 has been determined by single crystal X-ray diffraction. At circa 102 °C and 1 atm H 2, 1 will form the unsaturated compound (μ-H) 2Os 3(CO) 9{P(CH 2CH 2(CF 2) 5CF 3) 3} ( 5) in modest yield. Compound 5 and the related compound (μ-H) 2Os 3(CO) 9{P(C 6H 4-4-CH 2CH 2(CF 2) 7CF 3) 3} ( 6) are obtained more cleanly by treating (μ-H) 2Os 3(CO) 10 with the corresponding fluorous phosphine ligand at room temperature followed by decarbonylation in refluxing hexane. Compounds 1– 6 have been characterized by employment of IR and 1H NMR and 31P NMR spectroscopy. Partition coefficients between fluorous and non-fluorous solvents have been determined. The use of 6 as a ROMP catalyst with norbornene in a variety of organic and universal solvents is described.