Interconversion between the Enantiomers of Chiral Five-Coordinate Me3Pt(IV) Complexes

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• 作者：Runyu Tan ; Datong Song
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：November 7, 2011
• 年：2011
• 卷：50
• 期：21
• 页码：10614-10622
• 全文大小：1017K
• 年卷期：v.50,no.21(November 7, 2011)
• ISSN：1520-510X

文摘

The dinuclear Me₂Pt(II) complexes of 3,4-bis(quinolin-8-yl)thiophene (1a), 3,4-bis(6 trifluoromethoxyquinolin-8-yl)thiophene (1b), and 3,4-bis(2-methylquinolin-8-yl)thiophene (1c) react with MeOTf (OTf = trifluoromethanesulfonate) to afford the corresponding chiral mononuclear five-coordinate Me₃Pt(IV) complexes [PtMe₃(1a)]OTf (3a), [PtMe₃(1b)]OTf (3b), and [PtMe₃(1c)]OTf (3c), respectively. [PtMe₃(1c)]BAr^F₄ (3d) (where BAr^F₄ = [B{C₆H₃-3,5-(CF₃)₂}₄]) has also been synthesized for structural study. While 3a appears to be symmetric in solution and asymmetric in solid state, 3c and 3d are asymmetric in both solution and solid state. The chirality originates from interligand repulsion, rather than any unsymmetrical ligand. Variable-temperature NMR and computational studies suggest a ligand-twisting isomerization pathway for the interconversion of the enantiomers, rather than the rotational exchange of three CH₃ ligands on the metal center.