title: Theoretical studies on electron delocalization in diaminoguanidine.
abstract: Ab initio MO and density functional methods have been employed to understand the electronic structure and second-order delocalizations in diaminoguanidine. The potential energy surfaces of the three different positional isomers of diaminoguanidine (DAG1, DAG2, and DAG3) have been studied in detail, which suggest greater stability for DAG1 over the other isomers. Natural Population Analysis (NPA) has been employed to understand the primary and the secondary electron delocalizations in diaminoguanidine. The absolute proton affinity of diaminoguanidine is greater than both guanidine as well as aminoguanidine due to the extra stability from the intramolecular interactions in protonated diaminoguanidine. The increase in the electron delocalization upon protonation in diaminoguanidine is similar to that of guanidine and aminoguanidine.
authors.affiliation: Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar (Mohali), 160 062 Punjab, India. pvbharatam@niper.ac.in
authors.forename: Prasad V
authors.initials: PV
authors.lastname: Bharatam
authors.forename: Pansy
authors.initials: P
authors.lastname: Iqbal