Photochemical linkage isomerization in coordinated sulfur dioxide

Photocrystallographic structure determination of a new geometric isomer of [Ru(NH3)4(H2O)(η1-OSO)][MeC6H4SO3]2

“…The resulting coordinates were then used to represent the ground state component of the model as a fixed rigid-body in the refinement of the photoactivated data. As suggested by Johnson and Dew, 9 and confirmed by our further photocrystallographic experiments at elevated temperatures, the MS1 state can be generated with lower efficiency at up to 120 K, and decomposes rapidly with almost complete conversion into the MS2 state above 160 K. The MS2 state, when cooled below 120 K and further irradiated, similarly converts into the MS1 state. Fig.…”

“…20%, the remaining 80% comprising the unchanged ground state structure. 9 The photochemically activated interconversion modes between the two metastable species, MS1 and MS2, proposed as a result of the spectroscopic studies, carried out at 25 K, are illustrated in Scheme 1. 7,8 This isomer had previously been reported as metastable state 2, MS2, by Johnson and Dew 9 from spectroscopic studies, in which a second metastable isomer, MS1, was also identified at a temperature of 25 K. For MS1 the bonding mode was not identified unambiguously but it was proposed that it might involve an g 1 -OSO coordination.…”

Isomerization in Photochromic Ruthenium Sulfoxide Complexes

“…[77][78][79] The first report of a photogenerated SO 2 metastable state was from Johnson and Dew. [80] On the basis of infrared spectroscopy, they found that irradiation of [Ru(NH 3 ) 4 Cl(SO 2 )]Cl in the solid state at low temperature produced ultimately two isomers. The first isomer was confidently ascribed to an η 2 -SO 2 isomer based on differences between symmetric and asymmetric ν(S=O) stretches and 18 O isotopic studies.…”

Effects of the reaction cavity on metastable optical excitation in ruthenium-sulfur dioxide complexes

“…For example, the general class of compounds ͓Ru͑SO 2 ͒͑NH 3 ͒ 4 X͔Y also exhibits a side-bound and an endbound metastable state ͑Fig. 1͒, studied initially in IR spectra 10 and later via x-ray diffraction and DFT calculations. [11][12][13] If these or related compounds are to be useful in optical data storage, then controlled, ideally complete, conversion to their photoisomers is important for ease of reading.…”