Comparison of the substituent effects in tetrazole systems and benzene. A computational study

Natural Population Analysis of two tautomeric forms of 16 tetrazole derivatives substituted at carbon atom (AlH2, BeH, BH2, CCH, CF3, CHO, Cl, CN, F, Me, NH2, NO, NO2, OH, SH, SiH3) was carried out at B3LYP/6-31G(d,p) level of theory and compared with data for monosubstituted benzene derivatives. The individual occupancies of 2pz orbitals at all atoms of the tetrazole and benzene derivatives were correlated with the sum of occupation overall 2pz orbitals, named pEDA(A) or pEDA(B), respectively. These characteristics correlate well with the Hammett-like substituent constants. Acceptable correlations between the individual atom occupancies at the 2pz orbital and pEDA were found for all atoms except N4.