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Titolo:
S-0 and S-1 states of monochlorophenols: Ab initio CASSCF MO study
Autore:
Hirokawa, S; Imasaka, T; Imasaka, T;
Indirizzi:
Kyushu Inst Design, Dept Environm Design, Chem Lab, Minami Ku, Fukuoka 8158540, Japan Kyushu Inst Design Fukuoka Japan 8158540 nami Ku, Fukuoka 8158540, Japan Kyushu Univ, Grad Sch Engn, Dept Chem Syst & Engn, Funct Mat Chem Grp, Fukuoka 81281, Japan Kyushu Univ Fukuoka Japan 81281 Funct Mat Chem Grp, Fukuoka 81281, Japan
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY A
fascicolo: 40, volume: 105, anno: 2001,
pagine: 9252 - 9257
SICI:
1089-5639(20011011)105:40<9252:SASSOM>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
SUPERSONIC JET SPECTROSCOPY; SET MODEL CHEMISTRY; ROTATIONAL ISOMERS; CONFIGURATION-INTERACTION; 1ST-ROW ELEMENTS; TOTAL ENERGIES; DIPOLE-MOMENT; HARTREE-FOCK; PHENOL; HYDROGEN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
52
Recensione:
Indirizzi per estratti:
Indirizzo: Hirokawa, S Kyushu Inst Design, Dept Environm Design, Chem Lab, Minami Ku,Fukuoka 8158540, Japan Kyushu Inst Design Fukuoka Japan 8158540 uoka 8158540, Japan
Citazione:
S. Hirokawa et al., "S-0 and S-1 states of monochlorophenols: Ab initio CASSCF MO study", J PHYS CH A, 105(40), 2001, pp. 9252-9257

Abstract

Optimized geometries and total energies for the So and S, states of five monochlorophenols and phenol were calculated using a 10-electron, 8-orbital CASSCF/6-31G(d). We investigated the effects of a substituent chlorine atomand the S-1 <-- S-0 excitation on the geometries and charge distributions. It is common to all monochlorophenols that the substituent chlorine atom makes the C-O bond shorten and that an empirical rule with respect to the internal ring angle concerned with the substituent chlorine atom holds true. The S-1 <-- S-0 excitation enlarges the carbon ring and reduces the C-H, C-O, and C-CI bond lengths. The O-H bond length and the C-O-H bond angle are almost invariant upon excitation. A structural approach based on van der Waals radii has clarified that cis-o-chlorophenol has a hydrogen bond in the S-1 state and that the interaction between the chlorine and oxygen atoms ina trans-o-chlorophenol affects its geometries for the S-0 and S-1 states. As to the origin energies of the S-1 <-- S-0 transitions, the present method can compete in terms of accuracy with a 8-electron, 7-orbital CASSCF/6-31G(d,p). The increasing order of the calculated origin transition energies of monochlorophenols and phenol is in qualitative agreement with experimental results. Zero-point corrections are important in identifying the electronic spectra of monochlorophenols. The relative stabilities of rotational isomers, and dipole moments as well, have been also studied in relation to experimental results.

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Documento generato il 05/04/20 alle ore 03:56:30