Substituted Metal Carbonyls. 26.1 One-Step Synthesis, Structures, NMR, and Dynamic Laser-Light Scattering of Re2(
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- 作者：Pauline M. N. Low ; Yuk Lin Yong ; Yaw Kai Yan ; T. S. Andy Hor ; Sik-Lok Lam ; Kam Kwong Chan ; Chi Wu ; Steve C. F. Au-Yeung ; Yuh-Sheng Wen ; and Ling-Kang Liu
- 刊名：Organometallics
- 出版年：1996
- 出版时间：March 5, 1996
- 年：1996
- 卷：15
- 期：5
- 页码：1369 - 1375
- 全文大小：255K
- 年卷期：v.15,no.5(March 5, 1996)
- ISSN：1520-6041
文摘
Oxidative decarbonylation of Re2(CO)10 byMe3NO in a mixture of THF and MeOHfollowedby addition of alkyl-chained diphosphinePh2P(CH2)nPPh2(PP) (n = 1-4) givesRe2(
-OMe)2(-PP)(CO)6 in 34, 29, 28, and 10% yields,respectively. This methanolytic oxidation acrossthe Re-Re bond provides a general and one-step route for thesynthesis of these dirheniumhexacarbonyl complexes with diphosphine and methoxo bridges. Themolecular structureofRe2(-OMe)2(-Ph2PCH2PPh2)(CO)6was determined by single-crystal X-ray diffractionanalysis. It contains twofac-[Re(CO)3] moieties bridged by dppmand two methoxo ligands.The {Re2O2} core is significantly moreplanar than that in theFe(C5H4PPh2)2analogue.That such a dinuclear core is maintained in spite of the differentsteric demands of thedifferent bridging diphosphines illustrates the great geometrictolerance of the bridgingmethoxo groups. The fluxionality of the dppm, dppe, and dpppcomplexes has been studiedand compared by molecular modeling and solution 1H NMRspectroscopy. Dynamic laser-light scattering (DLS) shows that the dppe complex aggregates inCH2Cl2 to form smallclusters with an average radius of ~370 nm. The use of acombination of DLS and NMR inorganometallic chemistry is unprecedented.
-OMe)2(-PP)(CO)6 in 34, 29, 28, and 10% yields,respectively. This methanolytic oxidation acrossthe Re-Re bond provides a general and one-step route for thesynthesis of these dirheniumhexacarbonyl complexes with diphosphine and methoxo bridges. Themolecular structureofRe2(-OMe)2(-Ph2PCH2PPh2)(CO)6was determined by single-crystal X-ray diffractionanalysis. It contains twofac-[Re(CO)3] moieties bridged by dppmand two methoxo ligands.The {Re2O2} core is significantly moreplanar than that in theFe(C5H4PPh2)2analogue.That such a dinuclear core is maintained in spite of the differentsteric demands of thedifferent bridging diphosphines illustrates the great geometrictolerance of the bridgingmethoxo groups. The fluxionality of the dppm, dppe, and dpppcomplexes has been studiedand compared by molecular modeling and solution 1H NMRspectroscopy. Dynamic laser-light scattering (DLS) shows that the dppe complex aggregates inCH2Cl2 to form smallclusters with an average radius of ~370 nm. The use of acombination of DLS and NMR inorganometallic chemistry is unprecedented.