Table 1: Molecular descriptors values involved in the QSPR models for N-bases and predicted pKa values.

Comp.
no.
HNMVFFNSA3FPSA1MNRI-CMERI-CHDSA1/TMSAWPSA2 ESP-HDCA1/TMSA Exp.
pKa
Model I
pKa
Model II
pKa
Model
III pKa

13.2116E + 03−0.01210.69710.02360.02550.000067.28030.03060.00005.17005.33015.27674.7608
2a3.2085E + 03−0.01260.72200.02680.02980.092794.98030.03100.01755.68005.21185.89555.9027
33.2070E + 03−0.01060.75660.02380.02540.0996146.44190.03080.01766.00006.42866.68586.5446
43.2163E + 03−0.01770.86050.02480.02830.0962148.56830.03300.01976.47006.26355.50304.4868
5a3.2047E + 03−0.02280.57360.02460.03130.000045.50350.03390.00001.45000.77973.57301.4487
63.2032E + 03−0.02080.60120.02270.03290.000084.26440.03250.00001.90001.78582.45572.0669
73.2167E + 03−0.02840.79320.02700.02980.082599.79730.08660.02283.23002.51172.85261.3664
8a3.2087E + 03−0.01090.60390.02360.02220.0000117.20820.03110.00004.80004.27315.50815.1457
93.2038E + 03−0.01110.63040.01810.02010.0000133.02260.03190.00005.40004.99225.90225.0948
103.2124E + 03−0.01860.60390.02830.03590.000027.65130.03560.00002.33002.04762.24862.7407
113.1506E + 03−0.01840.72040.03670.03530.000064.10770.04260.00001.30001.64661.51612.8224
123.2027E + 03−0.01460.70570.01450.01800.0000244.62930.03110.00004.82005.49334.80154.0070
133.5371E + 03−0.02580.69140.01970.02460.2577143.87800.05640.10239.75009.29879.99448.0521
143.4841E + 03−0.03860.66670.02570.03590.3736419.70910.08400.10633.30004.14323.57484.3398
15a3.4711E + 03−0.04420.57110.03830.04740.180759.16540.08080.05380.60000.01910.6357−1.2911
163.5160E + 03−0.03300.65130.04390.03730.2588139.83770.08420.09764.58004.34334.57395.4486
173.2125E + 03−0.01000.71680.02540.03140.0972129.97130.03070.01995.96005.97604.91716.8860
183.2150E + 03−0.02560.68690.02820.03380.078883.51740.09030.02091.25001.55571.51272.0909
19a3.2055E + 03−0.02720.65450.02260.02520.0905158.31180.08900.01642.21002.37041.70222.9931
203.1934E + 03−0.02550.69640.02260.02260.0874163.00470.08330.01683.26002.45032.75452.7138
213.2156E + 03−0.01950.72630.02740.03340.0962127.23440.04610.01913.06003.68483.54263.8711
223.2076E + 03−0.00810.72580.02450.02460.0895186.80040.02330.01626.71006.53866.37807.1975

aCompounds in the test set.