TY - JOUR
T1 - Vibronic interactions in {6} and {18}hetero(A,B)annulenes
AU - Tachibana, Masamitsu
AU - Yoshizawa, Kazunari
N1 - Funding Information:
This work was supported by a grant-in-aid for Scientific Research on the Priority Area “Molecular Physical Chemistry” from the Ministry of Education, Science, Sports and Culture of Japan. Computations were partly carried out at the Supercomputer Laboratory of Kyoto University and at the Computer Center of the Institute for Molecular Science.
PY - 2000/10/15
Y1 - 2000/10/15
N2 - The vibronic (vibrational-electronic) interactions and the Jahn-Teller effects in the monoanions and trianions of (6)hetero(B,N), (C,N), and (B,O)annulenes and (18)hetero(B,N), (C,N), and (B,O)annulenes are discussed. All the heteroannulenes have threefold axis of symmetry and the twofold degenerate lowest unoccupied molecular orbital (LUMOs), and the E' or E vibrational modes can cause Jahn-Teller distortions in their monoanions and trianions. State vibronic coupling constants of the monoanions and trianions and orbital vibronic coupling constants concerning the LUMOs are calculated for each Jahn-Teller active vibrational mode at the B3LYP/6-31G* level of theory. Vibrational modes near 1500 cm-1 of the {6}hetero(A,B)annulenes and low-frequency modes (<500 cm-1) of the {18}hetero(A,B)annulenes give large coupling constants, and therefore, these modes are essential in the Jahn-Teller distortions and the vibronic interactions. The coupling constants are qualitatively analyzed by looking at the nuclear motions of the Jahn-Teller active modes and the shapes of the LUMOs on the basis of one-electron approximation. (C) 2000 Published by Elsevier Science B.V.
AB - The vibronic (vibrational-electronic) interactions and the Jahn-Teller effects in the monoanions and trianions of (6)hetero(B,N), (C,N), and (B,O)annulenes and (18)hetero(B,N), (C,N), and (B,O)annulenes are discussed. All the heteroannulenes have threefold axis of symmetry and the twofold degenerate lowest unoccupied molecular orbital (LUMOs), and the E' or E vibrational modes can cause Jahn-Teller distortions in their monoanions and trianions. State vibronic coupling constants of the monoanions and trianions and orbital vibronic coupling constants concerning the LUMOs are calculated for each Jahn-Teller active vibrational mode at the B3LYP/6-31G* level of theory. Vibrational modes near 1500 cm-1 of the {6}hetero(A,B)annulenes and low-frequency modes (<500 cm-1) of the {18}hetero(A,B)annulenes give large coupling constants, and therefore, these modes are essential in the Jahn-Teller distortions and the vibronic interactions. The coupling constants are qualitatively analyzed by looking at the nuclear motions of the Jahn-Teller active modes and the shapes of the LUMOs on the basis of one-electron approximation. (C) 2000 Published by Elsevier Science B.V.
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U2 - 10.1016/S0301-0104(00)00282-2
DO - 10.1016/S0301-0104(00)00282-2
M3 - Article
AN - SCOPUS:0034668161
VL - 260
SP - 303
EP - 315
JO - Chemical Physics
JF - Chemical Physics
SN - 0301-0104
IS - 3
ER -