Characteristic Effects of 4,5-Disubstituted Pyridazin-3-one Derivatives with Various Functional Groups: Ab initio Study

Abstract

The geometrical structures of pyridazin-3-one derivatives (4,5-dihalopyridazin-3-one and 4-halo-5-alkoxypyridazin-3-one) with various functional and substituent groups were fully optimized using the ab initio Hartree-Fock (HF) and second order Möller-Plesset perturbation (MP2) methods. At the N2-, C4-, and C5-positions on the pyridazin-3-one rings, the structural and electronic features pertaining to the variations of the functional and substituent groups were analyzed, respectively. The trends in the variation of the bond lengths, atomic charges, and energetics (relative energy, binding energy) of the derivatives induced by changing the electron donating functional groups (X1 = OMe, OEt) to electron withdrawing groups (X1 = Cl, NO 2 ) were examined. The variations of the bond lengths, atomic charges, and binding energies with the electron withdrawing strength of the substituent groups (Y = Me → F) were also investigated.