Twisted internal charge transfer molecules: already twisted in the ground state

Abstract

frans-octatetraene and have reassigned it using ab initio SCF frequencies scaled by our technique. Although they do not correct for electron correlation as we do here, their scaled results are in good agreement with ours. Their proposed final assignment of the light molecule is essentially identical with ours. It is particularly pleasing that our prediction of a medium infrared band near 1580 cm'1 has been borne out by the new experiment. Several other weak bands that were predicted by theory have also been found. Another, very recent paper on this subject has been published by Zerbetto et al. [J. Chem. Phys. 1988, 89, 3681].Acknowledgment. Acknowledgment is made to the donors of the Petroleum Research Fund, administered by the American Chemistry Society, for support of this research. The calculations were performed with a Celerity 1200 minicomputer, purchased with support of the National Science Foundation, under Grant No. CH-8500487.

Direct Observation of a Hydrogen‐Bonded Charge‐Transfer State of 4‐Dimethylaminobenzonitrile in Methanol by Time‐Resolved IR Spectroscopy

“…Neglect of this major factor is considered to account for much of the difficulty in interpreting the fluorescence results. [2,8,[11][12][13] A mechanism of this kind has not to our knowledge been proposed before. We believe this interpretation is applicable to other molecules with solvent-dependent dual fluorescence.…”

“…[2] Hydrogen bonding in protic solvents can lead to complicated interactions [10] but although specific solute-solvent and solute-solute interactions have been discussed, [8,[11][12][13][14] there is no generally accepted explanation. There are similar problems in other cases of dual fluorescence.…”

Dual Fluorescence of 2-(4′-N,N-dimethylaminophenyl)pyrido [3,4-d]imidazole in a TritonX-100/n-Hexanol/Water Reverse Micelle in Cyclohexane: Effect of pH and Trifluoroacetic Acid

“…In most of these studies (7)(8)(9)(10)(11)(12), the formation and stabilization of the TICT state is attributed to viscosity and mainly to the polarity of the medium, suggesting that the energy barrier for the TICT state process decreases with the increase in the polarity of the medium. However, some authors (13)(14)(15), on one hand, have suggested that the specific hydrogen bonding between the electron donor group and the solvent molecules also plays a role in stabilizing the twisted conformer to facilitate the formation of the TICT state. On the other hand, Kim et al have shown that the hydrogen bonding of the electron acceptor group with the solvent molecules has played a major role in the stabilization of the TICT state and in the enhancement of the TICT emission in p-dimethylamino- (16) and p-diethylaminoaminobenzoic acid (17).…”

Fotoquímica de sistemas Areno/Olefina

“…La introducción de un grupo amino en el ciclo aromático, permite la aparición de interacciones entre el compuesto y el disolvente en el estado fundamental y en el estado excitado. [84][85][86][87][88][89][90] La influencia del disolvente sobre las aminas aromáticas se traduce no sólo en los efectos causados por la polarización electrónica, sino también en los efectos particulares generados por las interacciones locales como enlaces de hidrógeno y transferencias de protón. 85,86 La fotoquímica de las arilaminas no ha sido estudiada en profundidad, posiblemente porque estas moléculas presentan una alta luminiscencia y no son muy reactivas en procesos unimoleculares.…”

“…[84][85][86][87][88][89][90] La influencia del disolvente sobre las aminas aromáticas se traduce no sólo en los efectos causados por la polarización electrónica, sino también en los efectos particulares generados por las interacciones locales como enlaces de hidrógeno y transferencias de protón. 85,86 La fotoquímica de las arilaminas no ha sido estudiada en profundidad, posiblemente porque estas moléculas presentan una alta luminiscencia y no son muy reactivas en procesos unimoleculares. 84 Köhler, G. Los procesos que tienen lugar al excitar el cromóforo anilínico, son la eyección de un electrón del orbital p, generando el catión radical, o la ruptura homolítica del enlace N-H del grupo amino y que conduce a la formación del radical anilinio.…”