Structures, dipole moments and excited state lifetime of isolated 4-cyanoindole in its ground and lowest electronically excited singlet states

The electric dipole moments of the B1Σ+, C1Σ+, and A1Π states of the CO molecule have been determined by observing Stark effects on the Ångstrom and Herzberg bands. We find the excited B and C states to have dipole moments of (1.60 ± 0.15) and (4.52 ± 0.35) D respectively. The upper limit for the dipole moment of the A1Π state is (0.15 ± 0.05) D.

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Valence-shell expansion of phosphorus and arsenic in the ground and lowest electronically excited singlet states of phenylphosphonic and phenylarsonic acids

Analytica Chimica Acta ◽

10.1016/s0003-2670(01)82188-7 ◽

1973 ◽

Vol 63 (1) ◽

pp. 197-200 ◽

Cited By ~ 3

Author(s):

Stephen G. Schulman ◽

Pamela Liedke

Keyword(s):

Valence Shell ◽

Excited Singlet ◽

Singlet States ◽

Electronically Excited ◽

Excited Singlet States

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The Electric Dipole Moments of Methine Dyes – Comparison of Experimental Results with Theoretical Predictions

Zeitschrift für Naturforschung A ◽

10.1515/zna-1982-0907 ◽

1982 ◽

Vol 37 (9) ◽

pp. 1024-1026

Author(s):

Z. Salamon ◽

A. Skibiński ◽

K. Celnik

Keyword(s):

Dipole Moments ◽

Stokes Shift ◽

Emission Spectra ◽

Solvent Polarity ◽

Electronic Charge ◽

Excited Singlet ◽

Nonpolar Solvents ◽

Singlet States ◽

Theoretical Predictions ◽

Excited Singlet States

Abstract Absorption and emission spectra of methine dyes in polar and nonpolar solvents were measured. From the Stokes shift as a function of solvent polarity the dipole moments of excited singlet states have been estimated and compared with the quantum chemical predictions. Also the π-electronic charge distribution in the ground and first excited singlet electronic states and bond orders of the dyes were calculated. All investigated methines showed an increase in dipole moment upon excitation to the first excited emitting state.

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The photochemistry of indenyl alcohols and esters: Substituent effects on the competition between ion- and radical-derived products

Canadian Journal of Chemistry ◽

10.1139/v03-131 ◽

2003 ◽

Vol 81 (10) ◽

pp. 1083-1095 ◽

Cited By ~ 8

Author(s):

J A Pincock ◽

I S Young

Keyword(s):

Excited State ◽

Ground State ◽

Fluorescence Emission ◽

Substituent Effects ◽

Sharp Contrast ◽

Carboxylate Anion ◽

Excited Singlet ◽

Heterolytic Cleavage ◽

Singlet States ◽

Excited Singlet States

The photochemistry of the indenyl acetates 1 and pivalates 2, substituted with X = H, 5-CH3O, and 6-CH3O, have been examined in both methanol and cyclohexane. The precursor alcohols 3 were also found to be photoreactive. Although only radical-derived products were obtained in cyclohexane, both ion- and radical-derived products were formed in methanol. The absence of significant fluorescence emission from any of the substrates 1, 2, and 3 indicates that the excited singlet states are highly reactive. A mechanism is proposed for the ion-derived products that proceeds through direct heterolytic cleavage to give an indenyl cation carboxylate anion pair. The indenyl cations generated are anti-aromatic in the ground state and their efficient generation by this photochemical solvolysis is in sharp contrast to the very low reactivity of related ground-state substrates. For the pivalate esters 2, an excited-state migratory decarboxylation is proposed for the formation of tert-butyl derived products.Key words: ester photochemistry, indenyl cations, indenyl radicals.

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