Palladium(II) Complexes Containing Mixed Nitrogen-Sulphur Donor Ligands: Interaction of [Pd(Methionine Methyl Ester)(H₂O)₂]²⁺ with Biorelevant Ligands

Table 3

Formation constants for complexes of [Pd(MME)(H₂O)₂]²⁺ with dibasic acids at 25°C and 0.1 M ionic strength.

System	M	L	H^a
Cyclobutane-1,1-dicarboxylic acid	0	1	1	5.42 (0.00)	5.42
	0	1	2	8.06 (0.01)	2.64
	1	1	0	7.13 (0.01)
	1	1	1	8.95 (0.07)	1.82
Malonic acid	0	1	1	5.30 (0.00)	5.30
	0	1	2	7.86 (0.01)	2.56
	1	1	0	6.84 (0.06)
	1	1	1	10.29 (0.08)	3.45
Oxalic acid	0	1	1	3.83 (0.00)	3.83
	0	1	2	5.66 (0.01)	1.83
	1	1	0	7.16 (0.04)
	1	1	1	10.3 (0.05)	3.14
Succinic acid	0	1	1	5.21 (0.00)	5.21
	0	1	2	9.26 (0.00)	4.05
	1	1	0	4.27 (0.03)
	1	1	1	8.45 (0.08)	4.18
Adipic acid	0	1	1	5.11 (0.03)	5.11
	0	1	2	9.35 (0.04)	5.24
	1	1	0	4.11 (0.02)
	1	1	1	0.494 (0.04)	3.62

^aM, L, and H are the stoichiometric coefficients corresponding to Pd(MME), dibasic acids, and H⁺, respectively. ^b of Pd(MME)-dibasic acid complexes; standard deviations are given in parentheses; sum of square of residuals is less than . ^cThe p of ligands or the protonated complexes.