| 3 | Alternative synthetic route for the heterometallic CO-releasing [Sb@Rh_(12)(CO)_(27)]^(3-) icosahedral carbonyl cluster and synthesis of its new unsaturated [Sb@Rh_(12)(CO)_(24)]^(4-) and dimeric [{Sb@Rh_(12)Sb(CO)_(25)}_2Rh(CO)_2PPh_3]^(7-) derivatives显示文摘The hetero-metallic [Sb@Rh_(12)(CO)_(27)]^(3-)cluster has been known as for over three decades thanks to Vidal and co-workers, and represents the first example of an E-centered(E=heteroatom) icosahedral rhodium carbonyl cluster. However, its synthesis required high temperature(140–160 °C) and elevated CO pressure(400 atm).Applying the redox condensation method for cluster preparation, we herein report a new synthetic, high-yield route for preparing [Sb@Rh_(12)(CO)_(27)]^(3-)under much milder conditions of temperature and pressure. Notably,when the same synthesis was carried out under N_2 instead of CO atmosphere, the new isostructural but unsaturated derivative [Sb@Rh_(12)(CO)_(24)]^(4-)was obtained, for which we report the full X-ray structural characterization. This species represents one of the few examples of an icosahedral cluster disobeying the electron-counting Wade-Mingos rules, possessing less than the expected 170 cluster valence electrons(CVEs).Judging from IR monitoring, the two species can be obtained one from the other by switching between N_2 and CO atmosphere, making [Sb@Rh_(12)(CO)_(27)]^(3-)a spontaneous CO-releasing molecule. Finally, the study of the chemical reactivity of [Sb@Rh_(12)(CO)_(27)]^(3-)with PPh_3 allowed us to obtain the new [{Sb@Rh_(12)Sb(CO)_(25)}_2Rh(CO)_2PPh_3]^(7-)dimeric compound, for which we herein report the full X-ray structural and ^(31)P NMR analyses. | Cristina Femoni Iacopo Ciabatti Maria Carmela Iapalucci Silvia Ruggieri Stefano Zacchini | 2016 | Progress in Natural Science:Materials International2016，26，5： | 0 |
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