Syntheses and Reactivity of Functionalized (η5-Tetramethylcyclopentadienyl) Rhenium Complexes: Molecular Structures of (η5:η2-C5Me4CH2CH2CHCH2)Re(CO)2 and (η5-C5Me4CH2-2-C4H3S)Re(CO)2(PMe3)

The fulvene complexes (η6-C5Me4CH2)Re(CO)2R (1, R = C6F5; 2, R = I) react at the exocyclic methylene carbon with allylmagnesium chloride or 2-thienyllithium to yield the anionic species [(η5-C5Me4CH2L)Re(CO)2R]- (L = −CH2CHCH2, −2-C4H3S). Further reaction with CH3I at room temperature affords the methyl complexes (η5-C5Me4CH2L)Re(CO)2(R)(Me) (3, R = C6F5; 4, R = I). Protonation of the anionic species with HCl at low temperature gives the hydride complexes trans-(η5-C5Me4CH2L)Re(CO)2(R)(H) (5, R = C6F5; 6, R = I). Thermolysis of hexane solutions of 6, under CO atmosphere, produces the tricarbonyl complexes (η5-C5Me4CH2L)Re(CO)3 (7) in moderate yields; if the reaction is carried out in the presence of PMe3, the analogous dicarbonyl phosphine derivatives (η5-C5Me4CH2L)Re(CO)2(PMe3) (9) are obtained, but no coordination of the lateral functionality is observed. In clear contrast, thermolysis of hexane solutions of the pentafluorophenyl hydride complexes trans-(η5-C5Me4CH2L)Re(CO)2(C6F5)(H), even under CO atmo...