Rational Synthesis of Molybdenum(V) Tetramers Consisting of [Mo2O4]2+ Dimers Held Together by Bridging Phosphinate Ligands and the Tungsten(VI) Dimer [(CH3O)2(O)W(μ-O)(μ-O2PPh2)2W(O)(CH3O)2]: Structural and Theoretical Considerations
Autor: | Linsheng Feng, Ampa Jimtaisong, Rudy L. Luck, Craig A. Bayse, Soumya Sreehari |
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Rok vydání: | 2007 |
Předmět: | |
Zdroj: | Journal of Cluster Science. 19:181-195 |
ISSN: | 1572-8862 1040-7278 |
DOI: | 10.1007/s10876-007-0170-5 |
Popis: | Reacting MoO2(acac)2 with Ph2POOH or Me2POOH in EtOH results in the formation of the tetranuclear molybdenum (V) clusters Mo4(μ 3-O)4(μ-O2PR2)4O4, PR2 = PPh2, 1, or PMe2, 2, in functional yields (>90% and 55% respectively). The reaction of WO2(acac)2 with Ph2POOH in MeOH affords the tungsten dimer [(CH3O)2(O)W(μ-O)(μ-O2PPh2)2W(O)(CH3O)2], 3. The single crystal X-ray determined structures of complexes 1–3 are reported. In 1 and 2, the four Mo=O units are interconnected by four triply bridging oxygen atoms, resulting in a distorted cubic-like structure for the Mo4(μ 3-O)4O4 units. Each molybdenum atom forms two additional Mo–O bonds with two oxygen atoms from different adjacent phosphinato ligands. Complex 3, a tungsten dimer, contains packing disorder and consists of bridging oxo and diphenylphosphinato ligands. The bonding of 1 and 2 assessed by density-functional methods showed that bonding between the Mo(V) centers occurs through σ overlap of the d xy orbitals. |
Databáze: | OpenAIRE |
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