Theoretical investigations on the vibronic coupling between the electronic states S-0 and S-1 of formic acid including the photodissociation at 248 nm

Borges I; Rocha AB; Martinez-Nunez E; Vazquez S

Chemical Physics Letters, Vol.407, No.1-3, 166-170, 2005

DOI10.1016/j.cplett.2005.03.077 Export Citation

Theoretical investigations on the vibronic coupling between the electronic states S-0 and S-1 of formic acid including the photodissociation at 248 nm

Borges I, Rocha AB, Martinez-Nunez E, Vazquez S

We studied the vibronic coupling of the S-1 &LARR; S-0 transition in HCOOH and obtained partial and total optical oscillator strengths (OOS). Vibronic coupling is responsible for an increase of the total OOS of almost 50%. We confirmed theoretically that this diffuse absorption band corresponding to a n &RARR; π* transition has the major portion of the vibronic transition intensity associated with the C=O stretching and CH bendings normal modes. We also discussed the implications of the vibronic coupling results for internal conversion process between the two states followed by molecular photodissociation due to photon absorption at 248 nm. © 2005 Elsevier B.V. All rights reserved.