Soluble redox-active polymetallic chains [{Ru0(CO)(L)(bpy)}m](n) (bpy = 2,2'-bipyridine, L = PrCN, Cl-; m = 0, -1): electrosynthesis and characterization.

Electrochemical and spectroelectrochemical techniques were employed to study in detail the formation and so far unreported spectroscopic properties of soluble electroactive molecular chains with nonbridged metal-metal backbones, namely, [{Ru(0)(CO)(PrCN)(bpy)}(m)](n) (m = 0, -1) and [{Ru(0)(CO)(bpy)Cl}(m)](n) (m = -1, -2; bpy = 2,2'-bipyridine). The precursors cis-(Cl)-[Ru(II)(CO)(MeCN)(bpy)Cl(2)] (in PrCN) and mer-[Ru(II)(CO)(bpy)Cl(3)](-) (in tetrahydrofuran (THF) and PrCN) undergo one-electron reductions to reactive radicals [Ru(II)(CO)(MeCN)(bpy(*-))Cl(2)](-) and [Ru(II)(CO)(bpy(*-))Cl(3)](2-), respectively. Both [bpy(*-)]-containing species readily electropolymerize on concomitant dissociation of two chloride ligands and consumption of a second electron.

Syntheses, X-ray structures, photochemistry, redox properties, and DFT calculations of interconvertible fac- and mer-[Mn(SPS)(CO)3] isomers containing a flexible SPS-based pincer ligand.

The lithium salt of the anionic SPS pincer ligand composed of a central hypervalent lambda4-phosphinine ring bearing two ortho-positioned diphenylphosphine sulfide side arms reacts with [Mn(CO)5Br] to give fac-[Mn(SPS)(CO)3]. This isomer can be converted photochemically to mer-[Mn(SPS)(CO)3], with a very high quantum yield (0.80+/-0.

Redox-active polymers based on nonbridged metal-metal bonds. Electrochemical formation of [Os(bpy)(CO)(L)](n) (bpy = 2,2'-bipyridine; L = CO, MeCN) and of their reduced forms: a spectroelectrochemical study.

IR, UV-vis, and EPR spectroelectrochemistry at variable temperatures and in different solvents were applied to investigate in situ the formation of electroactive molecular chains with a nonbridged Os-Os backbone, in particular, the polymer [Os(0)(bpy)(CO)(2)](n) (bpy = 2,2'-bipyridine), from a mononuclear Os(II) carbonyl precursor, [Os(II)(bpy)(CO)(2)Cl(2)]. The one-electron-reduced form, [Os(II)(bpy(.)(-))(CO)(2)Cl(2)](-), has been characterized spectroscopically at low temperatures.

Electronic properties of 4,4',5,5'-tetramethyl-2,2'-biphosphinine (tmbp) in the redox series fac-[Mn(Br)(CO)3(tmbp)], [Mn(CO)3(tmbp)]2, and [Mn(CO)3(tmbp)](-): crystallographic, spectroelectrochemical, and DFT computational study.

Stepwise electrochemical reduction of the complex fac-[Mn(Br)(CO)(3)(tmbp)] (tmbp = 4,4',5,5'-tetramethyl-2,2'-biphosphinine) produces the dimer [Mn(CO)(3)(tmbp)](2) and the five-coordinate anion [Mn(CO)(3)(tmbp)](-). All three members of the redox series have been characterized by single-crystal X-ray diffraction. The crystallographic data provide valuable insight into the localization of the added electrons on the (carbonyl)manganese and tmbp centers.