OsHCl(CO)(PiPr3)2 as catalyst for ring-opening metathesis polymerization (ROMP) and tandem ROMP-hydrogenation of norbornene and 2,5-norbornadiene

Complex OsHCl(CO)(PiPr3)2 catalyzes the ring-opening metathesis polymerization (ROMP) of norbornene and 2,5-norbornadiene to give poly(norbornene) and poly(norbornadiene), respectively. In both cases the resulting polymers have a high cis (74-95%) content. The stereoregularity or tacticity of the cyclopentane and cyclopentene ring sequences in poly(norbornene) and poly(norbornadiene) estimated from the 13C{1H} NMR spectra of the hydrogenated derivatives was found to be syndiotactic. Complex OsHCl(CO)(PiPr3) 2 is also active in tandem ROMP-hydrogenation of norbornene and 2,5-norbornadiene. At 40°C and 3 atm of H2, poly(norbornene) is fully hydrogenated in 48 h, while poly(norbornadiene) is fully hydrogenated in 48 h at 75°C and 3 atm of H2. The complex RuHCl(CO)(P iPr3)2 is also active in ROMP and tandem ROMP-hydrogenation of norbornene, obtaining trans-poly(norbornene) and hydrogenated poly(norbornene), respectively. © 2004 Elsevier Inc. All rights reserved.We acknowledge financial support from the Spanish “Ministerio de Ciencia y Tecnología” (Projects PPQ2000- 0488-P4-02 and BQU2002-00606). M.O. acknowledges the Spanish MCYT for funding through the “Ramón y Cajal” Program.Peer Reviewe