Protonation versus oxidation in the reactions of trifluoroacetic acid with dinuclear osmium(I ) complexes: molecular structure of [Os2(MeCo2)2(µ-H)(CO)4(PMe2Ph)2][PF6]
| Autor: | Neil P. Randle, Paul A. Bates, Antony J. Deeming, Michael B. Hursthouse |
|---|---|
| Rok vydání: | 1988 |
| Předmět: | |
| Zdroj: | J. Chem. Soc., Dalton Trans.. :2753-2757 |
| ISSN: | 1364-5447 0300-9246 |
| Popis: | The room temperature reaction between trifluoroacetic acid and the osmium(I) dimer [Os2(MeCO2)2(CO)6] gives the osmium(II) compound [Os(CF3CO2)2(CO)3] as a single osmium product, which is also very easily prepared by the direction reaction of CF3CO2H with [Os3(CO)12] at above 160 °C. However, this acid protonates the more basic derivatives [Os2(MeCO2)2(CO)4L2](L = PMe2Ph, PMePh2, PPh3, or pyridine), to give the hydrido complexes [Os2(MeCO2)2(µ-H)(CO)4L2]+, isolated as the [(CF3CO2)2H]– or [PF6]– salts, which are stable to an excess of CF3CO2H. The X-ray structure of [Os2(MeCO2)2(µ-H)(CO)4(PMe2Ph)2][PF6] indicates that the overall geometry of the molecule is preserved on protonation although the Os ⋯ Os distance is increased to 3.075(1)A. Protonation of [Os2(MeCO2)2(CO)4(PMe2Ph)(PPh3)] leads to only a small reduction of the phosphorus–phosphorus nuclear spin–spin coupling constant from 3J= 59.3 to 4J= 46.0 Hz. The direct Os–Os bond is replaced by an interaction via a bridging hydride which substantially preseves the P–P coupling. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|