Theoretical study of several O-nitrosyl carboxylate compounds have been performed using quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods with 6-31G^(**) basis set.Geometries obtained...Theoretical study of several O-nitrosyl carboxylate compounds have been performed using quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods with 6-31G^(**) basis set.Geometries obtained from DFT calculations were used to perform the natural bond orbital(NBO)analysis.It is noted that weakness in the O_(3)-N_(2) bond is due to nO_(1)→σO_(3)-N_(2) delocalization and is responsible for the longer O_(3)-N_(2) bond lengths in O-nitrosyl carboxylate compounds.It is also noted that decreased occupancy of the localized σO_(3)-N_(2) orbital in the idealized Lewis structure,or increased occupancy of σO_(3)-N_(2) of the non-Lewis orbital,and their subsequent impact on molecular stability and geometry(bond lengths)are related with the resulting p character of the corresponding sulfur natural hybrid orbital(NHO)of σ_(O_(3)-N_(2)) bond orbital.In addition,the charge transfer energy decreases with the increase of the Hammett constants of subsitutent groups.展开更多
基金We gratefully thank the National Natural Science Foundation of China(Grant No.10774039)the grant from Development Program in Science and Technology of Henan Province(Grant No.102300410114)Foundation for University Key Teacher by the Ministry of Education of Henan Province,and Henan University of Science and Technology for Young Scholars(Grant No.2009QN0032)for their support of this work.
文摘Theoretical study of several O-nitrosyl carboxylate compounds have been performed using quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods with 6-31G^(**) basis set.Geometries obtained from DFT calculations were used to perform the natural bond orbital(NBO)analysis.It is noted that weakness in the O_(3)-N_(2) bond is due to nO_(1)→σO_(3)-N_(2) delocalization and is responsible for the longer O_(3)-N_(2) bond lengths in O-nitrosyl carboxylate compounds.It is also noted that decreased occupancy of the localized σO_(3)-N_(2) orbital in the idealized Lewis structure,or increased occupancy of σO_(3)-N_(2) of the non-Lewis orbital,and their subsequent impact on molecular stability and geometry(bond lengths)are related with the resulting p character of the corresponding sulfur natural hybrid orbital(NHO)of σ_(O_(3)-N_(2)) bond orbital.In addition,the charge transfer energy decreases with the increase of the Hammett constants of subsitutent groups.
