The exact mechanisms regulating conformational changes in the platelet-specific integrin alphaIIbbeta3 are not fully understood. However, a role exists for thiol/disulfide exchange in integrin conformational changes leading to altered disulfide bonding patterns, via its endogenous thiol isomerase activity. Nitric oxide (NO) accelerates this intrinsic enzymatic activity and, in doing so, reverses the activational state of the integrin on the platelet surface toward a more unactivated one.
View Article and Find Full Text PDFVoltammetric, photo-physical and photo-electrochemical properties of the Dawson polyoxometalate anions alpha-[S(2)M(18)O(62)](4-) (M = Mo, W) are presented, both in the presence and absence of a series of [Ru(II)L(n)](+/2+) cations [L(n) = (bpy)(3), (bpy)(2)(Im)(2), (bpy)(2)(dpq), (bpy)(2)(box) and (biq)(2)(box)]. Electrochemical processes for both the anion and Ru(II/III) couples were detected in solutions of the salts [Ru(II)L(n)](2)[S(2)M(18)O(62)] in dimethylformamide (0.1 M Bu(4)NPF(6)) by both cyclic and hydrodynamic voltammetries.
View Article and Find Full Text PDFThe synthesis and a detailed investigation into the electronic properties of mononuclear and dinuclear Ru(II) complexes of the ligand bis(2-hydroxyphenyl)-2,5-dihydropyrazine (H(2)BHD) is described. In these complexes the Ru(II) moieties are bound through O,N coordination to an anionic phenolate and the pyrazine bridge. Relatively few reports are available on the dinuclear complexes bridged across a phenolate and this study provides an opportunity to examine the impact of reduced oxygen donor ligands on metal-metal communication.
View Article and Find Full Text PDFA detailed spectroscopic and electrochemical study of a series of novel phenolate bound complexes, of general formulas [M(L-L)(2)(box)](PF(6)), where M is Os and Ru, L-L is 2,2-bipyridine or 2,2-biquinoline, and box is 2-(2-hydroxyphenyl)benzoxazole, is presented. The objectives of this study were to probe the origin of the LUMOs and HOMOs in these complexes, to elucidate the impact of metal and counter ligand on the electronic properties of the complex, and to identify the extent of orbital mixing in comparison with considerably more frequently studied quinoid complexes. [M(L-L)(2)(box)](PF(6)) complexes exhibit a rich electronic spectroscopy extending into the near infrared region and good photostability, making them potentially useful as solar sensitizers.
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