Quantum-chemical study of nitrosonium complexes of monocyclic aromatic compounds

With the use of Hartree-Fock and DFT methods we demonstrated that for the benzene derivatives with the substituents Me, Et, Pr, i-Pr, t-Bu, CF3, F, and Cl pi-complexes are more favorable by energy, whereas with the substituents CHO, MeCO, PhCO, CN, NO, and NO2 n-complexes are more feasible. The affi nity of aromatic compounds to the nitrosonium-cation (A(NO)+) at the formation of the pi-complexes grows with the growing donor character of the substituents in the ring and with their number. The best agreement between the calculated and experimental A(NO)+ values for benzene was obtained with the use of RI-MP2/L1 method.