A Novel Route to Cationic Four-Coordinate Rhodium(I) Complexes with Rh=C Bonds

Autor: Justin Wolf, Oliver Nürnberg, Helmut Werner, Bettina Windmüller
Rok vydání: 1999
Předmět:
Zdroj: European Journal of Inorganic Chemistry. 1999:613-619
ISSN: 1099-0682
1434-1948
DOI: 10.1002/(sici)1099-0682(199904)1999:4<613::aid-ejic613>3.0.co;2-l
Popis: The complex [Rh(acetone)2(C8H14)2]PF6 (2), which is prepared from [RhCl(C8H14)2]2 and AgPF6 in acetone, reacts with PiPr3 to afford the PF6 salt 3 of the cation [Rh(acetone)2(PiPr3)2]+ containing the ketone and phosphane ligands in cis dispositions. Treatment of 3 with MeC≡CPh leads to the displacement of one acetone ligand and the formation of the corresponding π-alkyne complex 4. In contrast, from 3 and terminal alkynes such as HC≡CC6H4–4-Me or HC≡CCPh2OH the cationic vinylidenerhodium(I) compounds 5 and 6 are obtained. The latter, with C=CHCPh2OH as the ligand, is rather labile and even at room temperature eliminates water to give the cationic four-coordinate rhodium allenylidene 7. The molecular structure of this compound has been determined by X-ray crystallography. In the presence of pyridine or ammonia, the acetone ligand of 5 and 7 is readily displaced and the substitution products 8–10 are formed almost quantitatively. Anions such as acetate or hydroxide also displace the ketone unit of 7 and yield the neutral allenylidenerhodium(I) complexes trans-[RhX(=C=C=CPh2)(PiPr3)2] with × = OAc (11) and OH (12).
Databáze: OpenAIRE
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