Rhenium redox reactions

Ligand induced redox reactions of low oxidation state rhenium halides and related systems in non-aqueous solvents. R. A. Walton, Prog. Inorg. Chem., 1976, 21, 105-127 181). 

Although these complicated features of the redox reactions of technetium are important topics, the present article is limited to the susbtitution kinetics of technetium complexes. Some redox kinetics of technetium complexes have been discussed by Koltunov and Gomonova [6], The redox potentials for analogous technetium and rhenium complexes, based on their differences, have been compiled by Deutsch et al. [7],... 

Rearrangements of clusters, i.e. changes of cluster shape and increase and decrease of the number of cluster metal atoms, have already been mentioned with pyrolysis reactions and heterometallic cluster synthesis in chapter 2.4. Furthermore, cluster rearrangements can occur under conditions which are similar to those used to form simple clusters, e.g. simple redox reactions interconvert four to fifteen atom rhodium clusters (12,14, 280). Hard-base-induced disproportionation reactions lead to many atom clusters of rhenium (17), ruthenium and osmium (233), iron (108), rhodium (22, 88, 277), and iridium (28). And the interaction of metal carbonyl anions and clusters produces bigger clusters of iron (102, 367), ruthenium, and osmium (249). 

The decacarbonyls of manganese, technetium, and rhenium, of formula M2(CO)io, have terminal carbonyl groups and a metal-metal bond. The molecular symmetry is D d with the two M(CO)s fragments in a staggered conformation. The heterodinuclear decacarbonyl MnRe(CO)io is also known as obtained by the redox reaction of a rhenium pentacarbonyl halide with the pentacarbonylmanganate(-I) anion at room temperature (at 160 °C or higher, the heterodinuclear carbonyl tends to form the homodinuclear compounds with an equilibrium constant close to the statistical value ). The X-ray diffraction stndy of MnRe(CO)io has shown the Mn-Re distance of 2.909 A to be shorter than the sum of the covalent radii obtained from the homodinuclear compounds (Table 3). 

The objective of this work was to compare the catalytic properties of Pt-Re/Al203-Cl catalysts prepared either by the surface redox reaction or by classical coimpregnation. According to Augustine and Sachtler [15-16], the interactions between platinum and rhenium were probed by using hydrogenolysis of cyclopentane as a test reaction. 

Bimetallic platinum-rhenium catalysts were prepared either by coimpregnation or by catalytic reduction (redox reaction). 

Bimetallic platinum-rhenium catalysts can be prepared in aqueous acid medium, under hydrogen flow, by a redox reaction between hydrogen activated on a parent platinum-alumina catalyst and the perrhenate ion ReO4. ... 

Introduction.—The organometallic chemistry of technetium and rhenium reported during 1974 has been surveyed. The ligand-induced redox reactions of rhenium halides have been reviewed, and the chemistry of cyanide complexes of Group Vila metals has received attention. The electrochemistry of technetium and rhenium has been the subject of two reviews, and a general monograph on the production, uses, and disposal of technetium has appeared. Recently published crystal structures of complexes of technetium and rhenium have been collated. ... 

Reported rhenium complexes possess one [70-74], two [75], and three [75] dithiocarboxylato ligands coordinated to the one rhenium atom to form a high coordination state, as in the case of the technetium complex [76]. One of these complexes 29 is synthesized from Re(VII)S4 and (PhCSS)2 (Fig. 10) [72]. An internal redox reaction occurs and Re( VII) is reduced to Re(III) in the synthetic process. Addition of sulfur-abstracting reagents, Ph3P or Et4NCN, produces the heptacoordinate complex 30 with the neutral capped octahedron structure or... 

Numerous studies were devoted to the use of bimetallic catalysts, promoted either by an active metal such as rhenium or iridium, or an inactive one such as tin or germanium. These different catalysts were generally prepared by co-impregnation or successive impregnations. Moreover, most of the catalysts prepared by redox reactions were only evaluated in model reactions. For example, Corro et al. [87] prepared Pt-Sn/Al203-Cl catalysts by catalytic reduction or co-impregnation and compared their resistance to coking under cyclopentane feed. Thus, catalysts prepared by the surface redox reaction were less sensitive than the others to deactivation. This result was explained in terms of a more effective interaction between... 

Walton, R. A., Ligand-Induced Redox Reactions of Low Oxidation State Rhenium Halides and Related System in Nonaqueous dvents. m.m. 21 105... 

PANI composites with the oxides of technetium and rhenium are scarcely reported. The formation of PANl/Ca-sihcate/rhenium oxide composite upon the uptake of pollutant ReO from aqueous solution by the nanostructured PANI/Ca-silicate composite via the redox reaction between PANI leucoemeraldine/emeraldine salt (reductant) and ReO (oxidant) was reported by Cairns [185] and Borrmann et al. [186]. 

Some platinum metals, especially ruthenium but also rhenium, osmium, and iridium, form luminescent complexes with nitrogen-containing ligands, e.g., 2,2 -bipyridine (bpy). These complexes may participate in redox reactions with concomitant chemiluminescence in three different ways. 

The reactions of perfluoro-(l-methylpropenyl)silver with chromium-(p. 292), manganese- and rhenium- (p. 298), iron- (p. 303), and cobalt-halogen compounds (p. 318), and its redox reactions with the decacarbonyl-dimetallate ions [Ma(CO)i ] (M = Cr, Mo, or W) (p. 292), have already been described. With di(7r-Qrclopentadienyl)-titanium and -zirconium dichlorides, however, only the corresponding difluorides (w-C5H )aMFa (M = Ti or 7jl) are obtained. ... 

The main goals of this research are (1) to characterize polynuclear rhenium complexes which are capable of multielectron transfer reactions (2) to come up with appropriate conclusions on the redox-initiated transformations of this synthetic analog through the use of a new design of spectroelectrochemical cell and (3) propose possible systems or investigations where infrared spectroelectrochemi-stiy can be very useful. 

Rhenium(III) tris-chelates are formed by the reaction of 2-(diphenylphosphinomethyl)-4-methylphenol, PpOH (258a), or 2-diphenylphosphinophenol, P2-OH (258b) with [ReCl3(PPh3)2(CH3CN)] in a 1 3 ratio. [Re(Pi-0)3] is stable as solid and in solutions while [Re(P2-0)3] is easily oxidized in air giving the rhenium(V) 0x0 complex [Re0(P2-0)2(0P2-0]. This behavior is also reflected in the electrochemical behavior of the compounds, where each one well-defined redox couple for one-electron oxidation and reduction steps are observed for both compounds. A second oxidative wave (Re /Re ) is only reversible for [Re(Pi-0)3]. 

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