Fig. 17. Variation in the 1H NMR chemical shift of ethyl CH3 protons of aqua diastereomers 2Aw (RRu*RN*) and 2Bw (SRu*RN*) of [(h6-Bip)Ru(H2O)(Et-en)]2+ (6 mM Ru in 10% D2O/90%H2O) as a function of pH. The curves are computer-fits giving pKa (H2O) of 7.57 (± 0.01) for 2Aw and 7.35 (± 0.01) for 2Bw.