Bridging ligands tellurium

The dimeric tellurium diimides can act as chelating or bridging ligands. In the cis,exo,exo conformation, the formation of A. TV -chclated complexes is... 

Single crystal X-ray structural analyses of these compounds3,4 show that the tellurium atom is surrounded by four sulfur atoms from four different dithiophosphate groups in a planar arrangement. The S —P —S group is not a bidentate ligand but serves as a bridge between tellurium atoms. 

Complexes with sulfur, selenium, and tellurium bridging ligands... 

The situation close to that described above for sulfur is characteristic for the chal-cogenide elements. Atomic selenium [1,26,82-86] and tellurium [86] are part of di-, tri-, and polynuclear clusters, while diatomic molecules of these elements, when acting as ligands, have mostly a bridge function 52. Examples of di- and trinuclear monochalcogenide compounds are the complexes 53 and 54 [82-85] ... 

Complexes 56 [87] and 57 [82-85] are of considerable interest. During the formation of the first compound, both atomic and molecular tellurium participate simultaneously in the second one, Te2 carries out the functions of a-bridge and 7t-donor ligand [82-85], The cases are known when two diselenide bridges (for example, 58) and pentaselenide rj1 -terminal (59) ligation occurs [82-85] ... 

The reaction mixture containing tellurium bis[0-ethyl dithiocarbonate] and 4,4 -bipyridyl in diethyl ether deposited orange crystals of an adduct in which the bipyridyl ligand bridges two molecules of tellurium bis[0-ethyl dithiocarbonate]. The tellurium atom is located in the center of a pentagonal plane defined by four sulfur atoms and one nitrogen atom3. 

Tellurium tetrakis[2,2,2-trifluoroethoxide] reacted with 1,4,7,10-tetraazacyclododecane (LH4) in tetrahydrofuran/pentane at — 20° to yield a cationic tellurium complex with two LH4 ligands, two tellurium atoms, and two bridging oxygen atoms4. The compound, isolated as the chloride, crystallized with four molecules of chloroform and two molecules of methanol. 

Halocarbonylmanganese4 and halocarbonylrhenium complexes5 reacted with diphenyl ditellurium. The resulting tellurium-containing coordination compounds had intact bridging diphenyl ditellurium moieties and no benzenetellurolate ligands. 

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