Selenium Compounds with Low Phosphorus Coordination

A handful of P/Se compounds with low phosphorns coordination have been prepared. These include an iminoselenoxophosphorane which is formed in reaction 

Selenium will react with the diphosphene indicated to give a selenodiphosphirane and a diselenoxo-phosphorane. Snch a reaction may, like its snlphnr analogue (9.609), proceed via an intermediate phos-phinyhdene selenoxophosphorane. 

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