A QSPR Study for the Prediction of the pKa of N-Base Ligands and Formation Constant Kc of Bis(2,2′-bipyridine)Platinum(II)-N-Base Adducts Using Quantum Mechanically Derived Descriptors

Table 2

QSPR models of pKa for N-base ligands.

Models	Descriptors involved	𝐶^a	t-test	Statistical parameters
				Training set (N = 17)			Test set (N = 5)
				𝑅^2	𝑅^2cv	𝐹	𝑆^2	𝑅^2ext.	RMSE
Model I pKa	Intercept	−68.69	−12.73	0.95	0.89	61.79	0.311	0.97	0.51
	HNMVF	0.0216	13.60
	FNSA3	244.02	10.22
	FPSA1	13.96	6.33
	MNRI-C	−89.88	−3.92
Model II pKa	Intercept	16.23	16.43	0.94	0.89	56.62	0.33	0.85	1.11
	MERI-C	−328.98	−10.45
	HDSA1/TMSA	26.94	11.58
	WPSA2	−0.0163	−6.51
	Q max	−48.37	−6.38
Model III pKa	Intercept	8.55	10.30	0.76	0.61	23.37	1.32	0.91	0.93
	HDCA1/TMSA	73.89	6.43
	FNSA3	312.25	6.29

^aC: indicates the coefficients of the descriptors involved in the models, 𝑅²: the square of the regression correlation coefficient, 𝑅²_cv: the cross-validated square of the regression correlation coefficient, 𝐹: the 𝐹-value for the regression, 𝑆²: the standard deviation of the regression, 𝑅²_pred.: the predicted square of the regression correlation coefficient, RMSE: the root mean square error.