Several new arene-phosphine ligands were synthesized and used to prepare the following series of tethered dialkylruthenium(II) complexes: (η 6 :η 1 -C 6 H 5 CH 2 CH 2 PR 2 )Ru(CH 3 ) 2 , where R ) Cy (1), Ph (2), Et (3). The structures of complexes 1 and 2 were determined by X-ray diffraction. While complexes 1 and 2 were found to be more thermally stable than analogous nontethered analogues, complex 3 was found to decompose at room temperature. In preliminary studies, the use of complexes 1 and 2 as catalyst precursors for the polymerization of ethylene was examined.
Ruthenium−hydride olefin complexes having the formula [(η6-C6H5CH2CH2PR2)RuH(CH2CH2)][PF6], where R = Cy (1) and Ph (2), were prepared via the reaction of triphenylcarbenium hexafluorophosphate (Ph3CPF6) with the corresponding (η6-C6H5CH2CH2PR2)Ru(CH3)2
complexes. Reversible olefin−hydride insertion reactions were directly observed for both 1
and 2 by 2D EXSY magnetic resonance experiments. The structure of complex 1 was
determined by X-ray crystallography.
The reactions of (η 6 :η 1 -C 6 H 5 CH 2 CH 2 PR 2 )Ru(CH 3 ) 2 , where R ) Cy (1), Ph (2), with boron activators in the presence of CO, acetylene, ethylene, and norbornene were explored. The reaction of 1 and 2 with H( and 4, respectively). The reaction of 1 and 2 with H + Bin the presence of acetylene afforded polyacetylene and [(η 6 -C 6 H 5 -CH 2 CH 2 PR 2 )Ru(η 3 -CH 3 CHC 5 H 5 )][B(3,5-C 6 H 3 (CF 3 ) 2 ) 4 ] (5 and 6, respectively). The latter reactions were proposed to proceed via coordinative insertion of acetylene into Ru-alkyl bonds. In contrast, the reaction of 2 with H + Bin the presence of ethylene initially afforded the precursor complex [(η 6 :η 7). Finally, the reaction of 1 and 2 with H + Bin the presence of excess norbornene afforded ring-opened polynorbornene, presumably via Ru-catalyzed ring-opening metathesis polymerization (ROMP). The reaction products were characterized by IR and NMR spectroscopy. Single-crystal X-ray structural analyses of complexes 3, 5, 6, and 7 were also performed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.