Mixed rhenium

Fig. 5.. Mixed rhenium-platinum clu.ster synlhese.s utilizing (PK/t-COitiCO) ,...

Rhenium(VI) complexes, 4,194 alkoxides, 4,196 amides, 4,194 amines, 4,199 carboxylates, 4,199 dimethylformamide, 4,199 dioxane, 4,198 halides, 4,195,199 2-hydroxypyridine, 4,199 imides, 4,194 magnetic behavior, 1,271 mixed sulfur-nitrogen compounds, 4,196 N heterocycles, 4,199 nitrides, 4,194 oxide halides, 4, 195 oxoanions,4,196 pyridine, 4,199 sulfates, 4,198 sulfur compounds, 4,196 tellurates, 4,198... 

Platinum-bound phosphine and rhenium-ligated carbonyl irreversibly exchange on w arming a solution of Re2Pt(/r-H)2(CO)j (PPh3)2l above 213 a mix-... 

Schiff bases provide useful mixed donor sets. The carbonyl function of the most frequently used ligands is derived from either 1,3-dicarbonyl compounds or salicylaldehyde. Favourable combinations involve O-, N- and S-donor atoms. A range of technetium and rhenium complexes exist with bi-, tri-, tetra- and pentadentate ligands. The geometry of these complexes depends on the number and type of coordinating atoms as well as on the chain length between the donor atoms in the SchifF-base ligands. 

Another type of mixed ligand technetium or rhenium complexes in the above sense contains two or more monodentate ligands (Fig. 26b). The six-coordinated polypyridyl-thiolato complexes of rhenium(V) [ReO(terpy)(SR)2] + [186] are an example. Further representatives are a variety of mixed-ligand complexes, combining tetramethylthiourea with dimethyldithiocarbamate [TcO(tu)2-((CH3)2NCSS)]2+ [194],... 

Scheme 17. Synthesis of mixed oxo-alkyi complexes of high valency technetium and rhenium...

A platinum-rhenium composite catalyst supported on the granular activated carbon (Pt-Re/C, 5 wt-Pt%, mixed molar ratio of Pt/Re = 2) [10] was prepared by a "dry-migration method" [33,34] as follows (1) The Pt/C catalyst prepared earlier (5 wt-metal%) was evacuated at 180°C for 1 h (2) The mixture (molar ratio of Pt/Re = 2) of the Pt/C catalyst and a cyclopentadienylrhenium tricarbonyl complex (Re(Cp)(CO)3) were stirred under nitrogen atmosphere at room temperature for 1 h and then heated at 100° for 1 h, with the temperature kept at a constant (3) This mixture was further stirred under hydrogen atmosphere at 240°C for 3 h and finally (4) the Pt-Re/C composite catalyst was evacuated at 180°C for 1 h. A platinum-tungsten composite catalyst supported on the granular activated carbon (Pt-W/C, 5 wt-Pt%, mixed molar ratio of Pt/W = 1) [5,6] was also prepared similarly by the dry-migration method. All the catalysts were evacuated inside the reactor at 150°C for 1 h before use. 

Mixed alkali-metal chalcogenolates have been synthesized for main group elements, such as aluminium,54,55 germanium, and tin as (6) (Scheme 2),56 or transition metals such as zirconium,57 60 iron,61,62 vanadium,63 nickel,64 rhenium,65 and cobalt,66 or lanthanide metals.67,68... 

In contrast, there are two dimeric compounds to consider. One is the oxo,oxo derivative 6, the other a mixed oxo,thio 7 (3). The oxo groups in all of 5-7 occupy terminal positions, as usual, whereas the thio group in 7 is in abridging position. Each rhenium atom in 7 is therefore six-coordinate by virtue of a short rhenium-rhenium distance, 277.7 pm. Ignoring that bond, the local geometry about the one rhenium is a severely-distorted square pyramid, whereas the oxo-rhenium moiety has a geometry best described as a trigonal bipyramid. 

The infrared, NMR, and electronic absorption spectra of the two complexes H2FeRu2Os(CO)i3 and H2FeRuOs2(CO)13 have been taken to indicate a structure for these compounds similar to H2FeRu3(CO)13. However, the infrared and low-temperature proton NMR spectra of both compounds indicate that they exist as a mixture of isomers the two projected isomers for H2FeRu2Os(CO)13 are shown in Fig. 58 (247). The mixed manganese and rhenium-osmium complexes, H3MOs3(CO)13, have been prepared by acidification of the reaction mix-... 

The process calls for feeding ethylene and mixed butylenes to the bottom of a reactor. The mixed butylenes consist of both butene-1 and butene-2. (Refer to Figure 1—10 to refresh your memory about the difference.) A slurry of rhenium-based catalyst is introduced at the top. As the ethylene and butylenes bubble past the catalyst, the ethylene and butene-2 will react to form propylene (the carbon count is right). Simultaneously, as the butene-2 is consumed, butene-1 isomerizes to create more. 

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