Calculations for the metal complexes using NBO analysis.

	EC of M(ii), N10, O12, and O17	E (2) energy (kcal mol−1)
		LP(N10) → LP*(M)	LP(O12) → LP*(M)	LP(O17) → LP*(M)
Cu(ii) complex	Cu33[core]4S(0.26)3d(9.28)4p(0.20)	21.29	16.63	11.84
	N10[core]2S(1.38)2p(4.23)3p(0.02)
	O12[core]2S(1.64)2p(5.00)3p(0.01)
	O17[core]2S(1.68)2p(5.14)3p(0.01)
Zn(ii) complex	Zn33[core]4S(0.24)3d(9.98)4p(0.20)	16.61	16.11	2.34
	N10[core]2S(1.40)2p(4.29)3p(0.02)
	O12[core]2S(1.64)2p(5.01)3p(0.01)
	O17[core]2S(1.69)2p(5.18)3p(0.01)
Cd(ii) complex	Cd33[core]5S(0.22)4d(9.99)5p(0.12)	5.05	6.03	0.28
	N10[core]2S(1.41)2p(4.27)3p(0.02)
	O12[core]2S(1.65)2p(4.99)3p(0.01)
	O17[core]2S(1.70)2p(5.18)3p(0.01)
Pb(ii) complex	Pb33[core]6S(1.95)6p(0.32)	18.20	4.67	1.16
	N10[core]2S(1.41)2p(4.23)3p(0.02)
	O12[core]2S(1.67)2p(4.99)3p(0.01)
	O17[core]2S(1.71)2p(5.17)3p(0.01)