A proton nuclear magnetic resonance investigation of the protonation of bis(ethylenediamine)glycinatocobalt(III) in strongly acidic media
Abstract
The protonation equilibrium [Co(en)2(glyO)]2++ D+⇌[Co(en)2(glyOD)]3+ in strongly acidic solution has been investigated by 1H n.m.r. spectroscopy (en = ethylenediamine, glyO = glycinate). Similar pKBD+ values (ca. –1.2) are observed in D2SO4 and DCl solutions. Plots of log10([BD+]/[B])versus D0 are linear but with a slope between 0.4 and 0.5 indicating that the protonated complex has a much larger solvation requirement than its conjugate base.