Effects of hydrogen bond on 2-aminopyridine and its derivatives complexes in methanol solvent.
In the present work, the time-dependent density functional theory (TD-DFT) method was adopted to investigate the excited state hydrogen-bond dynamics of 2-aminopyridine monomer (2AP) and its derivatives in hydrogen donating methanol solvent. The calculated steady-state absorption and fluorescence spectra agree well with the experimental results. Theoretical results state that the bond lengths of both O-H and N-H bands are lengthened, while the intermolecular hydrogen bond lengths are shortened in the excited state. Further, the intermolecular hydrogen bonds are proved to be strengthened according to the calculated binding energy. As a reasonable explanation, the hydrogen bonds binding energy increases with multiple hydrogen-bonding interactions in the electronically excited state. In addition, the hydrogen bonding dynamics in the excited state were visualized by the spectral shifts of vibrational modes. The calculated infrared spectra of both O-H and N-H stretching vibrational regions revealed that the O-H and N-H stretching bands red-shift.
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China; State Key Lab of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
Jinfeng
J
Zhao
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China. Electronic address: songpeng@lnu.edu.cn.
Peng
P
Song
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China.
Yanling
Y
Cui
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China.
Xuemei
X
Liu
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China.
Shaowu
S
Sun
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China.
Siyao
S
Hou
Department of Physics and Chemistry, Liaoning University, Shenyang 110036, PR China. Electronic address: fcma@lnu.edu.cn.
Fengcai
F
Ma
D000631:Aminopyridines / Q000737:chemistry*; D006860:Hydrogen Bonding; D000432:Methanol / Q000737:chemistry*; D008958:Models, Molecular; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared
D000631:Aminopyridines; D012997:Solvents; C032439:alpha-aminopyridine; D000432:Methanol
Electronically excited state; Fluorescence spectrum; Frontier molecular orbitals; Infrared spectra; Intermolecular hydrogen bond