TY - JOUR
T1 - IR-dip and IR-UV hole-burning spectra of jet-cooled 4-aminobenzonitrile-(H2O)1. Observation of π-type and σ-type hydrogen-bonded conformers in the CN site
AU - Sakota, Kenji
AU - Yamamoto, Norifumi
AU - Ohashi, Kazuhiko
AU - Saeki, Morihisa
AU - Ishiuchi, Shunichi
AU - Sakai, Makoto
AU - Fujii, Masaaki
AU - Sekiya, Hiroshi
N1 - Funding Information:
The authors thank Prof. H. J. Neusser for valuable discussions. This work was supported by the Joint Studies Program (2000 and 2001) of the Institute for Molecular Science and Grant-in-Aid for Scientific Research No.1440177 from the Ministry of Education, Science, Sports and Culture.
PY - 2002/10/1
Y1 - 2002/10/1
N2 - The IR-dip spectra and IR-UV hole-burning spectra of jet-cooled 4-aminobenzonitrile-water 1: 1 complex have been measured to investigate the effects of the introduction of two substituents into the aromatic ring on the hydrogen-bonding interaction and stable structures of the complex. We have obtained a clear evidence for the observation of three structural isomers by comparing the experimental IR spectra with the theoretical ones. The water molecule is bonded to the NH2 site in isomer I, where the amino group can act as a proton donor and the amino hydrogen is bonded to the oxygen atom of water. Water is bonded to the CN site in isomers II and III. The structure of isomer II is very similar to benzonitrile-(H2O)1, where the water hydrogen is bonded to the cyano nitrogen and the oxygen atom of water is bonded to the ortho hydrogen atom. The water hydrogen is linearly hydrogen-bonded to the cyano nitrogen in isomer III. The intermolecular hydrogen bond in isomer II is σ-type, whereas that in isomer III is π-type. The proton-donor conformer in the NH2 site and the σ-type linear conformer in the CN site have not been observed in the aniline-(H2O)1 and benzonitrile-(H2O)1 complexes, respectively. The observation of three stable structures has been successfully explained by atomic charges on the constituent atoms obtained by natural population analysis.
AB - The IR-dip spectra and IR-UV hole-burning spectra of jet-cooled 4-aminobenzonitrile-water 1: 1 complex have been measured to investigate the effects of the introduction of two substituents into the aromatic ring on the hydrogen-bonding interaction and stable structures of the complex. We have obtained a clear evidence for the observation of three structural isomers by comparing the experimental IR spectra with the theoretical ones. The water molecule is bonded to the NH2 site in isomer I, where the amino group can act as a proton donor and the amino hydrogen is bonded to the oxygen atom of water. Water is bonded to the CN site in isomers II and III. The structure of isomer II is very similar to benzonitrile-(H2O)1, where the water hydrogen is bonded to the cyano nitrogen and the oxygen atom of water is bonded to the ortho hydrogen atom. The water hydrogen is linearly hydrogen-bonded to the cyano nitrogen in isomer III. The intermolecular hydrogen bond in isomer II is σ-type, whereas that in isomer III is π-type. The proton-donor conformer in the NH2 site and the σ-type linear conformer in the CN site have not been observed in the aniline-(H2O)1 and benzonitrile-(H2O)1 complexes, respectively. The observation of three stable structures has been successfully explained by atomic charges on the constituent atoms obtained by natural population analysis.
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U2 - 10.1016/S0301-0104(02)00501-3
DO - 10.1016/S0301-0104(02)00501-3
M3 - Article
AN - SCOPUS:0036784589
SN - 0301-0104
VL - 283
SP - 209
EP - 219
JO - Chemical Physics
JF - Chemical Physics
IS - 1-2
ER -