摘要:
Photolysis of the doubly bridged dicyclopentadienyl dimethyl dinuclear complexes [(eta(5)-C5H2R)(2)(SiMe2)(2)]-M-2(CO)(4)Me-2 (M = Ru, R = H (2a), Bu-t (2b); M = Fe, R = H (2c)) in benzene yields the corresponding methylene-bridged complexes [(eta(5)-C5H2R)(2)(SiMe2)(2)]M-2(CO)(2)(mu-CO)(mu-CH2) (3a-c) and the M-M-bonded complexes [(eta(5)-C5H2R)(2)(SiMe2)(2)]M-2(CO)(4) (1a-c). Irradiation of the analogous diethyl complex [(eta(5)-C5H2R)(2)(SiMe2)(2)]Ru-2(CO)(4)Et-2 (4) affords only 1a. Unlike the case for the doubly bridged complexes, photolysis of the singly bridged dicyclopentadienyl dimethyl diruthenium complexes [(eta(5)-C5H4)(2)(EMe2)]Ru-2(CO)(4)Me-2 (E = C (5a); E = Si (5b)) in benzene yields the corresponding "twisted" ruthenium methyl complexes with a cyclopentadienyl Ru sigma bond (eta(5),eta(5):eta(1)-C5H4(EMe2)C5H3)[Ru(CO)(2)][Ru(CO)(2)Me] (6a,b) and the similar phenyl complexes (eta(5),eta(5):eta(1)-C5H4(EMe2)C5H3)[Ru(CO)(2)][Ru(CO)(2)Ph] (7a,b), from reaction with the benzene solvent. Plausible mechanisms for the formation of the different types of products are proposed involving intramolecular C H bond activation. The molecular structures of 2a,c, 3a,c, 4, 5a, 6a, and 7h, determined by X-ray diffraction, are also presented.