Rhodium complex tellurium

The reaction of bis-phenylpropargyl ether (321) with tris(triphenylphosphine)rhodium chloride in benzene or toluene led to the formation of the unusual organometallic compound (322), which can be viewed as a derivative of an oxygen-rhodium pentalene system. Reaction of the rhodium complex (322) with sulfur leads to the corresponding 4,6-diphenyl-l,3-dihydro[3,4-c]furan (323). The selenium and tellurium analogs (324) and (325) were made in a similar manner (Scheme 111) (76LA1448). 

Benzenetellurolato-rhodium complexes were isolated when rhodium trichloride trihydrate and diphenyl tellurium were reacted in ethanol in the presence of formaldehyde. The benzenetellurolate ligand was formed by cleavage of one Te - C bond in diphenyl tellurium3. 

A series of quinones containing a tellurophene moiety 30 was obtained in 10-63% yield by coupling rhodium complexes with powdered tellurium (Equation 21) <19758265, 1975CB237>. In a similar way, the derivative 31 has been prepared (Equation 22) <1976LA1448>. 

Cyclopentadienyl(triisopropylphosphane)vinylidenerhodium reacted with tellurium in benzene to give a green ethenetellurolato-rhodium complex ... 

Quinones containing the tellurophene ring were obtained by Muller et al.ss by the reaction of an appropriate rhodium complex with amorphous tellurium (e.g., Section VI,D). 

A variety of quinones containing the tellurophene nucleus of general formula 49 have been obtained by Miiller et a/.55,100 by reaction between an appropriate rhodium complex (48) and amorphous tellurium as shown in Eq. (12). 

The same reaction, using elemental selenium or tellurium, gives the corresponding rhodium complexes. 

Selenium occurs in the slimes as intermetallic compounds such as copper silver selenide [12040-91 -4], CuAgSe disilver selenide [1302-09-6], Ag2Se and Cu2 Se [20405-64-5], where x < 1. The primary purpose of slimes treatment is the recovery of the precious metals gold, silver, platinum, palladium, and rhodium. The recovery of selenium is a secondary concern. Because of the complexity and variabiUty of slimes composition throughout the world, a number of processes have been developed to recover both the precious metals and selenium. More recently, the emphasis has switched to the development of processes which result in early recovery of the higher value precious metals. Selenium and tellurium are released in the later stages. Processes in use at the primary copper refineries are described in detail elsewhere (25—44). 

A tellurium-containing borane without carbon atoms in the Te — B cage was obtained from B10H14 and sodium polytelluride. The telluraborane BioHjjTe was used for the preparation of cobalt, iron, platinum, rhodium, and iridium complexes, in which the TeBioHjo moiety served as the ligand. 

The following metal compounds are used for the preparation of the catalysts oxides, metal carbonyls, halides, alkyl and allyl complexes, as well as molybdenum, tungsten, and rhenium sulfides. Oxides of iridium, osmium, ruthenium, rhodium, niobium, tantalum, lanthanum, tellurium, and tin are effective promoters, although their catalytic activity is considerably lower. Oxides of aluminum, silicon, titanium, manganese, zirconium as well as silicates and phosphates of these elements are utilized as supports. Also, mixtures of oxides are used. The best supports are those of alumina oxide and silica. 

The reaction of rhodium vinylidene metal complexes 3 with sulfur, selenium and tellurium affords complexes of metal substituted thio-, seleno- and telluroketenes 4. ... 

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