Autor según el artículo: De Graaf, C. ; Saure, S.

Departamento: Química Física i Inorgànica

Autor/es de la URV: DE GRAAF , CORNELIS; Saure, S.

Palabras clave: TD-DFT Fe(III) Complexes Light induced spin cross over

Resumen: Two light-induced spin-crossover Fe(III) compounds have been studied with time-dependent density functional theory (TD-DFT) to investigate the deactivation mechanism and the role of the ligand-eld states as intermediates in this process. The B3LYP* functional has previously shown its ability to accurately describe (light-induced) spin-crossover inFe(II) complexes. Here, we establish its performance for Fe(III) systems using [Fe(qsal)2]+(Hqsal=2-[(8-quinolinylimino)methyl] phenol) and [Fe(pap)2]+ (Hpap=2-(2-pyridylmethyleneamino)phenol) as test cases comparing the B3LYP* results to experimental information and to multicongurational wave function results. In addition to rather accurate high spin (HS) and low spin (LS) state geometries, B3LYP* also predicts ligand-to-metal charge transfer (LMCT) states with large oscillator strength in the energy range where the UV-VIS spectrum shows an intense absorption band, whereas optically allowed - excitations on the ligands were calculated at higher energy. Subsequently, we have generated a two-dimensional potential energy surface of the HS and LS states varying the Fe-N and Fe-O distances. LMCT and metal centered (MC) excited states were followed along the approximate minimal energy path that connects the minima of the HS and LS on this surface. The 2LMCT state has a minimum in the same region as the initial LS state, where we also observe a crossing with the intermediate spin (IS) state. Upon the expansion of the coordination sphere of the Fe(III) ion, the IS state crosses with the HS state and further expansion of the coordination sphere leads to the excited spin state trapping as observed in experiment. The calculation of the intersystem crossing rates reveals that the deactivation from 2LMCT!IS!HS competes with the 2LMCT!IS!LS pathway, in line with the low eciency encountered in experiments.

Grupo de investigación: Química Quàntica

Áreas temáticas: Química Química Chemistry

Acceso a la licencia de uso: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 1463-9076

Identificador del autor: 0000-0001-8114-6658;

Fecha de alta del registro: 2018-02-28

Página final: 1244

Versión del articulo depositado: info:eu-repo/semantics/submittedVersion

Enlace a la fuente original: http://pubs.rsc.org/en/content/articlelanding/2016/cp/c5cp06620d#!divAbstract

Programa de financiación: plan; Excelencia; CTQ2014-51938-P altres; Grupos Consolidados; 2014SGR199 altres; Xarxa d'R+D+I en Qumica Teorica i Computacional; XRQTC european; COST Action ECOSTBio; CM1305

DOI del artículo: 10.1039/C5CP06620D

Entidad: Universitat Rovira i Virgili

Año de publicación de la revista: 2016

Página inicial: 1233

Tipo de publicación: Article Artículo Article