title: Ab initio/DFT and AIM studies on dual hydrogen-bonded complexes of 2-hydroxypyridine/2-pyridone tautomerism.
abstract: The second-order Møller-Plesset (MP2) and density functional theory (DFT) calculations have been carried out to investigate the structures and stabilities of hydrogen (H-) bonded 2-hydroxypyridine (2HP)/2-pyridone (2PY) dimeric forms as well as 2HP-2PY complexes. The results on single-point counterpoise (CP) correction of these complexes were compared against CP-optimized correction. The nature of the intermolecular contacts in the sense of normal H-bond or blue-shifting H-bond was determined on the basis of harmonic vibrational, atom-in-molecule (AIM), and natural bond orbital (NBO) analysis. A blue-shifting C-H...N H-bond was found and NBO analysis revealed a slight decrease in the population of the contacting sigmaC-H* antibonding orbital as the primary reason of the C-H contraction. Good correlations have been established between the interaction energies and the H-bond distances versus other characteristic H-bond parameters.
authors.affiliation: Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, People's Republic of China.
authors.forename: Dong-ling
authors.initials: DL
authors.lastname: Wu
authors.forename: Lang
authors.initials: L
authors.lastname: Liu
authors.forename: Guang-fei
authors.initials: GF
authors.lastname: Liu
authors.forename: Dian-zeng
authors.initials: DZ
authors.lastname: Jia