title: Photoisomerization Mechanism of Ruthenium Sulfoxide Complexes: Role of the Metal-Centered Excited State in the Bond Rupture and Bond Construction Processes.
abstract: Phototriggered intramolecular isomerization in a series of ruthenium sulfoxide complexes, [Ru(L)(tpy)(DMSO)](n+) (where tpy=2,2':6',2''-terpyridine; DMSO=dimethyl sulfoxide; L=2,2'-bipyridine (bpy), n=2; N,N,N',N'-tetramethylethylenediamine (tmen) n=2; picolinate (pic), n=1; acetylacetonate (acac), n=1; oxalate (ox), n=0; malonate (mal), n=0), was investigated theoretically. It is observed that the metal-centered ligand field ((3) MC) state plays an important role in the excited state S→O isomerization of the coordinated DMSO ligand. If the population of (3) MCS state is thermally accessible and no (3) MCO can be populated from this state, photoisomerization will be turned off because the (3) MCS excited state is expected to lead to fast radiationless decay back to the original (1) GSS ground state or photodecomposition along the Ru(2+) -S stretching coordinate. On the contrary, if the population of (3) MCS (or (3) MCO ) state is inaccessible, photoinduced S→O isomerization can proceed adiabatically on the potential energy surface of the metal-to-ligand charge transfer excited states ((3) MLCTS →(3) MLCTO ). It is hoped that these results can provide valuable information for the excited state isomerization in photochromic d(6) transition-metal complexes, which is both experimentally and intellectually challenging as a field of study.
authors.affiliation: Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou, 341000, P. R. China. huifang0801@gmail.com.
authors.forename: Huifang
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou, 341000, P. R. China.
authors.forename: Lisheng
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou, 341000, P. R. China.
authors.forename: Lvyin
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou, 341000, P. R. China.
authors.forename: Xun
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou, 341000, P. R. China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, 361005, P. R. China. yizhao@xmu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhao
keywords: density functional calculations; organometallic chemistry; photochemistry; photochromic mechanisms; ruthenium