Rhenium redox properties

A novel HZSM-5-supported N-interstitial Reio cluster catalyst has now exhibited the highest phenol selectivity (93.9%) using O2 as the sole oxidant at a good benzene conversion of 9.9% [107]. Although rhenium with various valences possesses oxophilic and redox properties similar to molybdenum and vanadium, it has not been widely used as catalyst for selective oxidation because of the easy sublimation of Re207. However, rhenium acts as a good component of oxidation catalysts under reductive atmosphere, for example, coexisting with methanol [108-110] and ammonia [111-114]. 

Raman spectroscopy metal in water complexes, 309 Rare earth complexes acetylacetone synthesis, 377 guanidinium, 282 hydroxamic acids, 506 Redox properties bipyridyl metal complexes, 90 Reductive coupling nitrile metal complexes, 265 Resorcinol, 2,4-dinitro-metal complexes, 273 Rhenium complexes acetylacetone, 376 synthesis, 375, 378... 

Complex 4 and TpRe( = 0)Br2 (27) have been prepared by reaction of 3 with PPhs in the presence of Me3SiCl or Me3SiBr (Scheme 19). The reduction of 4 requires more forcing conditions relative to the technetium analog, consistent with the fact that reduction of rhenium complexes is typically less facile than corresponding technetium complexes. Replacement of chloride ligands with bromide does not significantly alter the redox properties of TpRe( = 0)X2 (X = Cl or Br). 

Tris(l,2-bis(dimethylphosphino)ethane)rhenium(I), [Re(DMPE)3]+ is a simple, symmetrical cation which contains three identical bidentate phosphine ligands. This complex provides a Re(II/I) redox couple with properties that are very convenient for the study of outer-sphere electron transfer reactions.1 Specifically, this couple is stable in both alkaline and acidic media and it exhibits a reversible, one-equivalent redox potential in an accessible region [ °,(II/I) = 565 mV vs. NHE]. Moreover, this complex has been used to obtain information about the biological mechanism of action of 186Re and l88Re radiopharmaceuticals.2,3... 

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. 

Other work has demonstrated that it is possible to switch ON and OFF luminescence by reduction/oxidation, and it has been demonstrated that such switching is possible inside an OTTLE cell. Many alkynyl complexes, especially those of rhenium, platinum,copper, silver or gold " are highly luminescent from their excited MLCT or metal perturbed 71 states. This opens up the possibility to significantly influence their emissive properties by redox processes. An interesting example is found in recent work of Wong et Unlike other rhenium(I)-alkynyl complexes, heterobimetallic... 

Interestingly, the electron reservoir properties of redox active ligands are also found to be useful to impose one-electron transformation on late transition metals. Rhenium complexes are known to be powerful oxo-transfer reagents [27]. However, closed-shell... 

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