title: Stability analysis of the two rotational isomers of meta-fluorobenzaldehyde in the S0, S1, and S2 electronic states.
abstract: For a determination of the stabilization energy between the two rotational isomers of m-fluorobenzaldehyde, the S(1,2)<--S0 absorption spectra were observed in fluid n-hexane solutions at 293 and 198 K. After employing a simulation method for the spectra, we succeeded in determining the stabilization energies in the ground and the relevant excited state at the same time. The energy was estimated to be 1.7 +/- 0.5 kJ mol(-1) for S0 and also for S1 while it was 2.9 +/- 0.5 kJ mol(-1) for S2. Ab initio calculations at MP2/6-311G** computational level predicted that the O-cis form in the S0 state is more stable by 1.9 +/- 0.5 kJ mol(-1) than the counterpart rotamer, O-trans form. In summary, a schematic energy level diagram of the two rotational isomers will be illustrated for the S0, S1, and S2 states in the fluid system.
authors.affiliation: Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Uejoh
authors.forename: Mariko
authors.initials: M
authors.lastname: Habu-Nishigori
authors.forename: Motohiko
authors.initials: M
authors.lastname: Koyanagi
mesh_terms: D001547:Benzaldehydes / Q000737:chemistry*; D004355:Drug Stability; D004563:Electrochemistry; D006586:Hexanes; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D001547:Benzaldehydes; D006586:Hexanes; D012996:Solutions; C026385:n-hexane