화학공학소재연구정보센터
Inorganic Chemistry, Vol.50, No.21, 10614-10622, 2011
Interconversion between the Enantiomers of Chiral Five-Coordinate Me3Pt(IV) Complexes
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)]3Ar(4)(F) (3d) (where BAr4F = [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.