Mechanistic and theoretical studies of the photochemistry of 5,6-dihydro-2-cyanobenzobarrelene

1979 ◽  
Vol 57 (21) ◽  
pp. 2804-2811 ◽  
Author(s):  
Christopher Owen Bender ◽  
Seamus F. O'Shea
Keyword(s):  
Excited States ◽  
Theoretical Studies ◽  
Interaction Energies ◽  
Deuterium Labelling ◽  
Atom Interaction ◽  
Ci Calculations

The direct (Φ6 = 0.04) or acetone sensitized (Φ6 = 0.51) photolysis of 2-cyano-1,4-dihydro-1,4-ethanonaphthalene (5) yields 1-cyanobenzotricyclo[3.3.0.02,8]octa-3-ene (6). Deuterium labelling studies suggest that 6 derives from a Zimmerman di-π-methane rearrangement and not from the McCullough 1-cyanocyclohexene rearrangement. The observed rearrangement and regioselectivity are in accord with predictions based upon CNDO-CI calculations of changes in atom–atom interaction energies on excitation to the S1 and T1 excited states of 5.

Polar substituents in barrelene photochemistry: mechanistic aspects of the photochemistry of 2-cyanobenzobarrelene

1978 ◽  
Vol 56 (23) ◽  
pp. 3027-3037 ◽  
Author(s):  
Christopher Owen Bender ◽  
Dee W. Brooks ◽  
William Cheng ◽  
Douglas Dolman ◽  
Seamus F. O'Shea ◽  
...  
Keyword(s):  
Excited States ◽  
Interaction Energies ◽  
Direct Photolysis ◽  
Deuterium Labelling ◽  
Atom Interaction ◽  
Polar Substituents ◽  
Triplet Excited States ◽  
Ci Calculations

The direct photolysis of 2-cyanobenzobarrelene (4) yields 5- and 7-cyanobenzocyclooctatetraene [Formula: see text] and 1-cyanobenzosemibullvalene [Formula: see text], whereas the acetophenone sensitized irradiation of 4 yields only 8 [Formula: see text]. Deuterium labelling studies suggest that 7 derives from an initial 2Π + 2Π cycloaddition between the vinyl and vinylcyano bridges of 4, whereas 8, resulting from direct or sensitized irradiations of 4, derives from di-Π-methane rearrangement involving initial vinyl–vinylcyano bridging. The observed initial bonding preferences of the 2Π + 2Π cycloadditions and di-Π-methane rearrangement of 4 are in accord with predictions based upon CNDO-CI calculations of changes in atom–atom interaction energies between possible bridging sites in singlet and triplet excited states of 4.

Substituent effects in arosemibullvalene photochemistry: the methylcyclopropane rearrangement of 1,8-dimethylbenzosemibullvalene

1982 ◽  
Vol 60 (15) ◽  
pp. 1942-1952 ◽  
Author(s):  
Christopher Owen Bender ◽  
Donald Laverne Bengtson ◽  
Douglas Dolman ◽  
Carolyn Elaine L. Herle ◽  
Seamus Francis O'Shea
Keyword(s):  
Gas Phase ◽  
Excited States ◽  
Substituent Effects ◽  
Interaction Energies ◽  
Direct Irradiation ◽  
Atom Interaction ◽  
Ci Calculations

1,6- and 1,8-Dimethylbenzotricyclo[3.3.0.02,8]octa-3,6-diene (16 and 14) are the major semibullvalene products formed from acetophenone sensitized irradiations of the barrelenes 2,6- and 2,3-dimethyl-1,4-dihydro-1,4-ethenonaphthalene (37 and 22), respectively (Φ37→16 = 0.65; Φ22→14=0.57). The direct (Φ14 = 0.017) or chlorobenzene sensitized (Φ14 = 0.12) irradiation of 14 yields 2,3-benzo-5-methyl-6-methylenebicyclo[3.3.0]octa-2,7-diene (17), a transformation typical of methylcyclopropanes. Gas phase thermolysis (420 °C/6 Torr) of 14 gives 6,7-dimethylbenzocyclooctatetraene (15). The direct irradiation (Φ39 = 0.003) or the gas phase thermolysis (395 °C/6 Torr) of 16 gives 6,9-dimethylbenzocyclooctatetraene (39). The rearrangement 14 → 17 is in accord with predictions based upon CNDO-CI calculations of changes in atom–atom interaction energies on excitation to the S1 or T1 excited states of 14.

Excited states of all-trans and 11-cis retinal: All valence-electron SCF-MO-CI calculations

2009 ◽  
Vol 9 (S2) ◽  
pp. 9-24
Author(s):  
Ludwik J. Weimann ◽  
Gerald M. Maggiora ◽  
Paul E. Blatz
Keyword(s):  
Excited States ◽  
Valence Electron ◽  
Ci Calculations

Theoretical Studies of Collision-induced Energy Transfer in Electronically Excited States

1990 ◽  
Vol 94 (11) ◽  
pp. 1253-1262 ◽  
Author(s):  
M. H. Alexander ◽  
A. Berning ◽  
A. Degli Esposti ◽  
A. Joerg ◽  
A. Kliesch ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited States ◽  
Theoretical Studies ◽  
Electronically Excited States ◽  
Electronically Excited

MRD CI calculations on the asymmetric stretch potentials of H2O in the ground and the first seven singlet excited states

1985 ◽  
Vol 96 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Giannoula Theodorakopoulos ◽  
Ioannis D. Petsalakis ◽  
Robert J. Buenker
Keyword(s):  
Excited States ◽  
Asymmetric Stretch ◽  
Ci Calculations

Theoretical Studies of the Excited States and Intra-ionic Charge Transfer of O-3

1996 ◽  
Vol 12 (02) ◽  
pp. 97-101
Author(s):  
Cao Ze-Xing ◽  
◽  
Huang Hong-Xin ◽  
Tian An-Min
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Theoretical Studies ◽  
Ionic Charge
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