Charge-transfer character of the intermolecular hydrogen bond in singlet and triplet excited electronic states of the adenine-thymine base pair

1982 ◽  
Vol 22 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Julio Marañón ◽  
Horacio Grinberg ◽  
Norma Sbarbati Nudelman
1989 ◽  
Vol 44 (11) ◽  
pp. 1057-1062
Author(s):  
U. Riedl ◽  
G. Gliemann

The polarized optical absorption and emission (spectra, decay times) of single-crystal [lr(CO)2mnt] TBA at temperatures 2 K≦T≤295 K and homogeneous magnetic fields O≦H≦6T are reported. The highly resolved spectra show 0-0 transitions with vibrational satellites and phonon side bands. Applied magnetic fields yield no effect on the emission. The lowest excited electronic states can be assigned to the spin-orbit components A′1 B′1 and B′1 of the charge transfer triplet 3A2 (symmetry C2v)


2021 ◽  
Vol 34 (1) ◽  
pp. 169-182
Author(s):  
Ruchi Kohli ◽  
Rupinder Preet Kaur

In the present study, a theoretical analysis of hydrogen bond formation of ethylene glycol, thioglycol, dithioglycol with single water molecule has been performed based on structural parameters of optimized geometries, interaction energies, deformation energies, orbital analysis and charge transfer. ab initio molecular orbital theory (MP2) method in conjunction with 6-31+G* basis set has been employed. Twelve aggregates of the selected molecules with water have been optimized at MP2/6-31+G* level and analyzed for intramolecular and intermolecular hydrogen bond interactions. The evaluated interaction energies suggest aggregates have hydrogen bonds of weak to moderate strength. Although the aggregates are primarily stabilized by conventional hydrogen bond donors and acceptors, yet C-H···O, S-H···O, O-H···S, etc. untraditional hydrogen bonds also contribute to stabilize many aggregates. The hydrogen bonding involving sulfur in the aggregates of thioglycol and dithioglycol is disfavoured electrostatically but favoured by charge transfer. Natural bond orbital (NBO) analysis has been employed to understand the role of electron delocalizations, bond polarizations, charge transfer, etc. as contributors to stabilization energy.


2000 ◽  
Vol 73 (8) ◽  
pp. 1783-1789 ◽  
Author(s):  
Satoshi Watanabe ◽  
Ken-ichi Kumagai ◽  
Miki Hasegawa ◽  
Michio Kobayashi ◽  
Jun Okubo ◽  
...  

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