An amorphous co‐polymer formed from norbornene and a photochromic ruthenium sulfoxide complex shows reversible macroscopic deformations when irradiated. Charge‐transfer excitation of the sulfur‐bonded isomer leads to isomerization and a macroscopic bending of the film. Charge‐transfer excitation of the oxygen‐bonded isomer reverses the bending. The macroscopic bending is ascribed to the molecular isomerization.

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Ruthenium(II) complexes of the primary phosphines PH2Fc and PH2CH2Fc and the secondary phosphine PH(CH2Fc)2, including [(p-cymene)RuCl(L)2](PF6) (p-cymene = p-iPrC6H4Me, L = PH2CH2Fc and PH(CH2Fc)2, 2b and 2c, respectively) and trans-[RuCl2(L)4] (L = PH2Fc, PH2CH2Fc, and PH(CH2Fc)2, 3a-c, respectively) were prepared and characterized by IR, 1H NMR, and 31P NMR spectroscopy. 3b was additionally characterized by X-ray crystallography. The spectroscopic effects of phosphine ligation were determined. Characteristic downfield shifts of the 31P NMR resonances and increases in energy of the nu(P-H) modes were observed in all cases. Iterative fitting of coupling constants to second-order NMR spectra also resulted in a complete elucidation of 31P-1H and 31P-31P couplings. This analysis provides a basis for considering the influence of coordinate bonding on the observed 1J(PH) and 2J(PP) constants.

We report the preparation and spectroscopic properties of [Os(bpy) 2 (pySO)] 2+ and [Os(bpy) 2 (pySOCF 3 )] 2+ , where bpy is 2,2Ј-bipyridine, pySO is 2-(propane-2-sulfinylmethyl)pyridine, and pySOCF 3 is 2-[(trifluoroethylsulfinyl)methyl]pyridine. The charge-transfer absorption spectra of [Os(bpy) 2 -(pySO)] 2+ and [Os(bpy) 2 (pySOCF 3 )] 2+ are 378 and 367 nm, respectively. Charge-transfer excitation of [Os(bpy) 2 -(pySOCF 3 )] 2+ shows substantial changes in the UV/Vis spectrum with a shift in the lowest energy absorption maximum from 367 to 415 nm, which is consistent with phototriggered SǞO isomerization. Irradiation of [Os(bpy) 2 (pySO)] 2+ shows no evidence of isomerization. Cyclic voltammograms of [Os(bpy) 2 (pySO)] 2+ and [Os(bpy) 2 (pySOCF 3 )] 2+ feature reversible one-electron couples that are ascribed to Os 3+/2+ reduction potentials (E°Ј) at 1.01 V (vs Ag/AgCl; ν = 0.1 V/s; CH 3 CN; 0.1 M TBAPF 6 ) and 1.17 V, respectively. Femto-

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