A Novel Cationic Optically Active Complex of Platinum(II) Containing 2-Methyl-2-butene and o-Benzenediamine. The Circular Dichroism Spectrum and Kinetics of Olefin Exchange

Article abstract of DOI:10.1246/bcsj.54.2309

An optically active cationic olefin complex, B(C6H5)4 was obtained for the first time as crystal stable in air at room temperature.It deteriorates slightly in solution, but is still stable enough to be characterized.Comparison of its CD spectrum with that of related complexes disclosed that the coordinating atoms at the cis sites to the olefin have a dominant influence upon the CD pattern in the region 20000-35000 cm^-1, as compared with those at the trans site.Substitution of cis-1,2-dichloroethylene for the coordinated (S)-2-methyl-2-butene (S-mbn) proceeds in accordance with the second order rate law; there is no contribution of the solvent path.The second order rate constant is smaller than that of trans-.The steric effect of the o-benzenediamine at the transition state seems responsible for the small rate rather than the basicity of the ligand at the trans site to mbn.