RACEMIZATION AND PROTON EXCHANGE AT ASYMMETRIC NITROGEN CENTERS IN PLATINUM(II) COMPLEXES

The platinum complexes Pt(Meen)Cl2, [Pt(Meen)(NH3)2)Cl2, [Pt(Meen)(NH3)2](BCS)2, [Pt(Meen)(phen)]Cl2·2H2O, and [Pt(Meen)(phen)](BCS)2·H2O have been prepared.2 The complex ions Pt(Meen)(NH3)2+2 and Pt(Meen)(phen)2+ have been resolved by fractional crystallization of the BCS salts from methanol and water, respectively. In these square-planar complexes the CH3NH nitrogen atom is the sole center of asymmetry. Racemization rates for these complexes are specific hydroxide ion catalyzed. Rates of exchange of the proton on the N-methyl nitrogen atom were followed by nmr by observing the growth of the methyl singlet on deuteration. These rates, also hydroxide ion catalyzed, were 100 and 2500 times greater than the racemization rates, respectively, for the diammine and phen complexes, indicating mainly a retention of configuration about the nitrogen for the deuteration process. © 1969, American Chemical Society. All rights reserved.