Tellurinium

Dibenzo[/j,e]seleninium cation Dibenzo[b,e]tellurinium cation... 

When the 4//-tellurins were heated in glacial acetic acid on a steam bath in the presence of hexafluorophosphoric add, tellurinium hexafluorophosphates were formed1 (p.813). 

The electrochemical reduction of the 4-(4//-tellurinyl)-4//-tellurin produced a tellurinium salt1. 

Diphenyl-4-ethoxy-l-tellurinium fluorosulfate reacted with 2,2-dimethyl-4,6-dioxo-1,3-dioxane (Meldrum s acid) to give 4-(2,2-dimethyl-4,6-dioxo-l, 3-dioxane-5-ylidene)-... 

When 2,6-diphenyl-4-methyl-l-tellurinium tetrafluoroborate and dimethylthioformamide were heated in acetic anhydride, 2,6-diphenyl-4-[2-(N,N-dimethyliminio)-ethylidene]-4H-tellurin tetrafluoroborate was isolated3. 

Methyltellurinium tetrafluoroborates condensed with 4-oxo-4//-tellurins to yield 4-( tellurinium-4-yl-melhylidene ) -4H-tellurinsx 4... 

Formylmethylidene)-4/7-tellurins were obtained as products of the reactions between tellurinium hexafluorophosphates and propionitriles5. 

When 4-(2,6-diphenyl-tellurinium-4-y]methylidene)-2,6-dipheny]-4/7-tellurin was reacted with one equivalent of chlorine, bromine, or iodine, only one tellurium atom was attacked with formation of 7e,7e-dihalides. When the halogens were added in excess, insoluble polyhalogenated materials were obtained1. 

Tellurins were converted to tellurinium hexafluorophosphates in degassed, refluxing glacial acetic acid in the presence of hexafluorophosphoric acid1. 

Diorgan o-4- ox o-4//-tellurin s were converted to tellurinium salts on treatment with ethyl fluorosulfate or 4-dimethylaminophenyl magnesium bromide1-3. 

Alky lmagnesi urn halides and 4-oxo-4f/-lellurins also yield tellurinium salts3. 

The condensations of tellurinium salts with Meldrum s acid1,4, with dimethyl-thionoformamide1,2, with 4-oxo-4//-chalcogenins, with 4-formylmethylidene-4//-chalcogenins2,5 6, with propionitriles7, and with oxygen to produce 4-alkylidene-4/7-tellurins or polymethine dyes are described on pages 815, 816. 

Treatment of 2-[2-(4-dimethylaminophenyl)-ethen-l-yl]-4-ethoxy-7-methoxy-l-benzo-tellurinium fluorosulfate dissolved in acetonitrile with 10% aqueous potassium carbonate produced 2- 2-(4-dimelhylaminophenyl)-ethen-l-yl ]-7-melhoxy-4-oxo-4H-l-benzotellurinx. 

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