Carbon-rich ruthenium complexes containing Bis(allenylidene) and mixed alkynyl-allenylidene bridges
Résumé
Complexes cis-[RuCl(dppe)(2)][X] (2a X=PF6, 2b X = CF3SO3) react with a variety of bis(propargylic) alcohols to selectively lead to mono-trans-[Cl(dppe)(2)Ru=C=C=C(R)-T-C(R) (OH)(CdropC-H)][X] (4) [R = H, Ph; T = m,p-(C6H4), 2,5-(thiophene), 5,5'-(2,2'-bithiophene), 5,5”-(2,2':5'2”-terthiophene), -CdropC-] or bis(allenylidene) trans-[Cl(dppe)(2)Ru=C=C=C(R)-T-(R)C= C=C=RuCl(dppe)(2)][X](2) (5) complexes. New dimetallic and trimetallic complexes containing mixed alkynyl-allenylidene bridges, trans-[Cl(dppe)(2)Ru-CdropC-p-(C6H4)-(Ph)C=C=C=RuCl(dppe)(2)][CF3SO3 ](12) and trans-[\Cl(dppe)(2)Ru-CdropC-p(C6H4)\(2)C=C=C=RuCl(dppe)(2)][CF3SO 3] (17), were prepared by modification of the carbon-rich ligand of acetylide precursors. UV/Vis and cyclic voltammetry studies show the influence of the unsaturated conjugated bridge on the electronic interaction between the redox centers, and the fine tuning of this property. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).