Excited state isomerization in photochromic ruthenium complexes

Abstract

Photochromic ruthenium polypyridyl complexes whose action is based on an excited state linkage isomerization are discussed. Picosecond transient absoption spectroscopic data indicate that isomerization occurs along the charge-transfer manifold. These studies indicate that rotation about the Ru-S bond is an important vibration along this coordinate. These complexes are of interest in photonic molecular devices, specifically molecular information storage applications.

Ultrafast reversible ligand isomerisation in Na2[Fe(CN)5NO]·2H2O single crystals

“…The targeted manipulation of molecules with light is of interest for potential applications such as light-induced NO-release for photodynamic therapy, 1 photochromic and photorefractive molecular compounds for optical devices, 2 or photoinduced chemical reactions. 3 The reversible photogeneration of metastable linkage isomers of ambidentate ligands such as N 2 , NO, NO 2 , SO [4][5][6][7][8][9] is an especially exciting case where the fundamental underlying principles of chemical bonding and light-driven molecular dynamics can be studied in detail. A large group of such photosensitive materials are transitionmetal complexes with the photoswitchable ligand NO.…”

Necessary conditions for the photogeneration of nitrosyl linkage isomers

“….). [1][2][3][4][5][6][7][8][9][10] Thereby the ligand Z can adopt different geometrical configurations that are stable at low enough temperatures, which allows for their determination by photocrystallographic methods. 11,12 Biatomic ligands, e.g.…”

Reversible photoswitching between nitrito-N and nitrito-O isomers in trans-[Ru(py)4(NO2)2]

“…6,7 Linkage isomers of various ligands Z have been generated in [ML y L t Z] n complexes by direct chemical reactions, 8 by variation of temperature and through redox-reactions in solutions, [9][10][11][12] through electrochemical oxidation, [13][14][15][16] by pH, 17 and especially through light-irradiation. 3,[18][19][20] Here M is the central atom, usually a transition metal, L y are equatorial ligands with coordination number y, and L t is the ligand trans to the photoswitchable ligand Z (e.g. Z = N 2 , NO, SO, SO 2 , NO 2 ).…”