P Mohammadzadeh Jahani - Department of medicine, Bam university of medical science, Bam, Iran
H Hamidian - Department of Chemistry, Payam Noor University. P.O. Box 19359-4697, Tehran, Iran
E Naroie - Department of Chemistry, Payam Noor University. P.O. Box 19359-4697, Tehran, Iran

Investigation of O-H…O intramolecular hydrogen bond (IMHB) in N-formal formamidicacid(NFF) and its derivatives were performed and their IMHB energies were obtained usingthe shuster and Spinosa methods.[1,2] Also the topological properties of electron densitydistribution and charge transfer energy associated with IMHB were gained by quantumtheory of atoms in molecules and natural bond orbital theory, respectively.