ISSN:
0009-2940
Keywords:
Titanocenes
;
Alkynyl ligands
;
Titanium complexes
;
Nickel complexes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Synthesis and Reactivity of {(η5-C5H4SiMe3)2Ti(C≡CPh)2}Ni(CO)The synthesis and reactivity of {(η5-C5H4SiMe3)2Ti(C≡CPh)2}Ni(CO) (6) is described. (η5-C5H4SiMe3)2Ti(C≡CPh)2 (1a) reacts with equimolar amounts of Ni(CO)4 (5) to afford the dinuclear complex {(η5-C5H4SiMe3)2Ti(C≡CPh)2}Ni(CO) (6) in 95% yield. In 6 both phenylethynyl units are η2-side-on-coordinated to the Ni(CO) moiety. When 6 is treated with HX or X2 (X = Cl, Br) the Ti-C(alkynyl) σ bond is cleaved, and the corresponding titanocene dihalides (η5-C5H4SiMe3)2TiX2 (7) are formed. With PRR′2 [8a: R = R′ = OMe; 8b: R = C = CPh, R′ = Ph; 8c: R = Ph, R′ = C≡CPh] 6 reacts by substitution of the nickel-bonded carbonyl ligand to form {(η5-C5H4SiMe3)2Ti(C≡CPh2}Ni(PRR'2) (9). The reactivity of 9b, which contains a noncoordinated phenylethynyl unit, has been investigated by using Co2(CO)8 (10) and Fe2-(CO)9 (13). With 10 the compounds {η5-C5H4SiMe3)2Ti(C≡CPh)2}Ni(CO) (6), [μ-(η2-Ph2PC≡CPh)]Co2(CO)6 (11) and {[μ-(η2-Ph2PC≡CPh)]Co2(CO)5}2 (12) can be obtained. Complex 11 yields upon heating by decarbonylation and dimerization the six-membered cyclic compound 12. Whereas, the reaction of 9b with 13 affords {(η5-C5H4SiMe3)2Ti(C≡CPh)2}Ni(CO) (6) next to the dinuclear complex Fe2(CO)6-(μ-PPh2)[μ-(η1:η2-C≡CPh)] (14).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250602
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