Table 1.

Apparent pK_a values determined for 1–5 and their [Ru(η⁶-C₆H₅CH₂CH₂NHR)(C₂O₄)(H₂O)] analogues.

Complex	Apparent pKa	Apparent pKa for the Analogous [Ru(η6-C6H5CH2CH2NHR)(C2O4)(H2O)] Complex
1	7.32	6.65 ‡
2	6.41	5.75
3	4.50	4.05 ‡
4	4.82	-
5	8.00	-

^‡ Values for [Ru(η⁶-C₆H₅CH₂CH₂NHR)(C₂O₄)(H₂O)] (R = Ms, Tf) have been reported previously [15].