RESUMO
The effects of ligand substitution and conformational flexibility on the ultrafast luminescent decay of [Re(CO)3(phen)(L)]+ (L = imidazole, pyridine) complexes are investigated by means of density functional theory (DFT/time-dependent DFT (TD-DFT)) electronic structure calculations and non-adiabatic quantum dynamics based on the linear vibronic coupling (LVC) approach including spin-orbit coupling (SOC) applied to the Cs conformers. The optical, luminescent and structural properties are not drastically affected either by the ligand substitution, or by the ligand rotation. However, the occurrence of two conformers, as investigated in detail for the pyridine substituted complex, significantly modifies the early time dynamics below 100 fs and the associated spin-vibronic mechanism.
RESUMO
We present a detailed study for the short-time dynamics through conical intersections in molecular systems related to the quadratic vibronic coupling (QVC) Hamiltonian [Müller, H.; Köppel, H.; Cederbaum, L. S. New J. Chem. 1993, 17, 7-29] and the effective-mode formalism [Cederbaum, L. S.; Gindensperger, E.; Burghardt, I. Phys. Rev. Lett. 2005, 94, 113003]. Our approach is based on splitting the nuclear degrees of freedom of the whole system into system modes and environment modes. It was found that only three-effective environmental modes together with the system's modes are needed to describe the short-time dynamics of the complex system correctly. In addition, a detailed mathematical proof is given in the appendix to demonstrate that the exact cumulants are recovered up to the second order within the cumulant expansion of the autocorrelation function. The butatriene molecule is studied as an explicit showcase example to stress the viability of our proposed scheme and to compare with other systems.
