Radiationless decay of vibronically coupled electronic states

Radiationless transitions from an optically prepared state to the ground state are studied on a model consisting of three electronic states and two harmonic modes of vibration. The effect of the upper excited state on the nonradiative decay properties of the lower excited state is investigated for systems in which these states are coupled through the same non‐totally‐symmetric mode that couples the lower excited state to the ground state. If only this mode is considered, the model is exactly solvable and allows one to test the assumption that the initially prepared state is an adiabatic Born–Oppenheimer state. This assumption is found to be accurate unless the zeroth‐order adiabatic vibrancy state from which the transition originates is very close to, e.g., within one vibrational quantum of, a zeroth‐order state of the upper excited state manifold. Strong nonadiabatic mixing occurs when a vibrationally excited level of the lower excited state is in resonance with a level of the upper state. In general, th...

[1]  William H. Miller.  Dynamics of Molecular Collisions , 1976 .

[2]  W. Siebrand.  Scaled and unscaled crude-adiabatic born-oppenheimer wavefunctions☆ , 1977 .

[3]  A. C. Albrecht.  ``Forbidden'' Character in Allowed Electronic Transitions , 1960 .

[4]  B. Hudson,et al.  Polyene spectroscopy: The lowest energy excited singlet state of diphenyloctatetraene and other linear polyenes , 1973 .

[5]  E. Feenberg.  A Note on Perturbation Theory , 1948 .

[6]  G. Orlandi,et al.  Vibronic coupling and line broadening in polyatomic molecules , 1971 .

[7]  O. Atabek,et al.  On the crude adiabatic molecular vibronic states and their use in the interpretation of radiationless processes in molecules , 1973 .

[8]  W. Siebrand,et al.  Vibrational progressions in vibronically induced transitions , 1976 .

[9]  W. A. Wassam,et al.  ’’Proximity effect’’ in radiationless transitions , 1978 .

[10]  M. Zgierski,et al.  Comparison of two linear approximations to vibronic coupling , 1977 .

[11]  F. Smith,et al.  DIABATIC AND ADIABATIC REPRESENTATIONS FOR ATOMIC COLLISION PROBLEMS. , 1969 .

[12]  Hajime Tanaka.  Adiabatic Process and the Stationary State , 1955 .

[13]  W. Siebrand,et al.  Exact solution of a vibronic coupling model and its implications for the herzberg—teller expansion method , 1975 .

[14]  W. Siebrand,et al.  A new perturbation approach to coupling between adiabatic states , 1974 .

[15]  W. Siebrand,et al.  Matrix elements for internal conversion , 1978 .

[16]  R. Silbey,et al.  Near resonance interactions in the B-O scheme. The vibronic mechanism pertinent to radiationless transitions and inhomogeneous line broadening , 1971 .

[17]  W. Siebrand,et al.  Nature of an optically prepared state undergoing radiationless decay , 1977 .

[18]  G. Orlandi.  The evaluation of vibronic coupling matrix elements , 1976 .

[19]  K. Watson,et al.  ENERGY OF A MANY-PARTICLE SYSTEM , 1956 .

[20]  W. Gelbart,et al.  Nonradiative electronic relaxation under collision-free conditions , 1977 .

[21]  W. H. Henneker,et al.  Exactly solvable models for vibronic coupling in molecular spectroscopy. II. Totally symmetric harmonic mode , 1976 .

[22]  R. L. Christensen,et al.  Vibronic coupling in polyenes: High resolution optical spectroscopy of 2,10‐dimethylundecapentaene , 1975 .

[23]  A. Nitzan,et al.  Intramolecular Nonradiative Transitions in the ``Non‐Condon'' Scheme , 1972 .