With Trialkylsilyl -germyl, -stannyl diorganophosphanes

Tellurium inserts into the P-group IV element bond in trialkylsilyl(-germyl, -stannyl)-diorganophosphanes in a benzene medium. The reaction proceeds via phosphane tellurides that rearrange to compounds with a P—Te-group IV element bond .  

The diorganophosphano trialkylsilyl(-germyl, -stannyl) tellurium compounds cannot be isolated because redistribution to the symmetrical tellurium derivatives takes place .  

Tributylphosphane telluride can be used in these reactions instead of elemental tellurium  

When a solution of bis[2,4,6-triethylphenyl]silylene-2,4,6-tri-/-butylphenylphosphane in tetrahydrofuran was stirred in the presence of tellurium for 48 h, tellurium formed a bridge between the P and the Si atoms. The cyclic P —Te—Si compound could be flash-chromatographed on alumina with pentane, but decomposed in air within ten minutes with deposition of a blackish, metallic material.  

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