Sterically Induced Conformational Relaxation and Structure of <i>meso</i>-Diaryloctaalkyl
Porphyrins in the Excited Triplet State: Experimental and DFT Studies
Alexander Kyrychenko
Joakim Andréasson
Jerker Mårtensson
Bo Albinsson
10.1021/jp021432u.s001
https://acs.figshare.com/articles/journal_contribution/Sterically_Induced_Conformational_Relaxation_and_Structure_of_i_meso_i_-Diaryloctaalkyl_Porphyrins_in_the_Excited_Triplet_State_Experimental_and_DFT_Studies/3723702
The excited triplet state conformations of zinc and free base 5,15-diaryloctaalkylporhyrins are studied by
experimental and computational (density functional theory, DFT) methods. From the observations of an unusual
triplet state dynamics, i.e., fast nonradiative and biexponential decay, it has been suggested that these porphyrins
exist in two distinguishable conformers in the lowest excited triplet state. X-ray crystallography and DFT
(B3LYP/6-31G(d)) optimization of the ground state show that the porphyrins are planar prior to excitation.
However, in the excited triplet state, the planar structure relaxes to an out-of-plane distorted saddle-shaped
conformer. This distorted conformer and the lowest triplet potential energy surface are characterized by DFT
calculations. It is suggested that the conformational relaxation explains the unusual triplet dynamics of this
class of porphyrins.
2002-11-07 00:00:00
triplet state dynamics
Sterically Induced Conformational Relaxation
triplet state
ground state show
conformer
triplet state conformations
DFT
porphyrin
B 3LYP optimization