Lowest excited triplet state of 2,5-dimethyl-1,3,5-hexatriene: Resonance Raman spectra and quantum chemical calculations

Journal Article · Thu Sep 05 00:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100171a029· OSTI ID:5260132

Negri, F; Orlandi, G ^[1]; Brouwer, A M ^[2]; Langkilde, F W ^[3]; Moeller, S; Wilbrandt, R ^[4]

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1. Univ. of Bologna (Italy)
2. Univ. of Amsterdam (Netherlands)
3. Royal Danish School of Pharmacy, Copenhagen (Denmark)
4. Risoe National Lab., Roskilde (Denmark)

Theoretical and Raman spectroscopic studies are presented of the ground and lowest triplet states of (E)- and (Z)-2,5-dimethyl-1,3,5-hexatriene and their 3,4-dideuterio and 3-deuterio isotopomers. The T{sub 1} and S{sub 0} states. Energies of higher triplet levels are computed and oscillator strengths for the T{sub 1} {yields} T{sub n} transitions are determined. The displacements in equilibrium geometries between the T{sub 1} and the T{sub n} level corresponding to the strongest T{sub 1} {yields} T{sub n} transition are calculated and are used to estimate the intensities of the resonance Raman spectra of the T{sub 1} state under the assumption of a predominant Franck-Condon scattering mechanism. The influence of the ground-state conformation around C-C single bonds on T{sub 1} resonance Raman spectra is considered in detail for the two isomers. It is found that for the E isomers the tEt and for the Z isomers the tEc forms are the predominant ones in the T{sub 1} state. The Z forms are at considerable higher energy than the E forms in the E forms in the T{sub 1} state due to nonbonded interaction. A good agreement is found between theoretically calculated and experimental spectra. The results are compared with previously published data for 1,3,5-hexatriene.

• OSTI ID: 5260132
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:18; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
ALKENES
CONFIGURATION INTERACTION
DATA
DEUTERIUM
ELECTRONIC STRUCTURE
ENERGY
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FRANCK-CONDON PRINCIPLE
GROUND STATES
HEXENES
HYDROCARBONS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPES
LABELLED COMPOUNDS
LASER SPECTROSCOPY
LIGHT NUCLEI
MATHEMATICAL MODELS
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OSCILLATION MODES
POTENTIAL ENERGY
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SCATTERING
SELF-CONSISTENT FIELD
SPECTRA
SPECTROSCOPY
STABLE ISOTOPES
THEORETICAL DATA