Phosphinidene, PH

Unstable phosphinidene, PH, has been detected in interstellar space and in planetary atmospheres. 

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Most phosphorus radicals, like the well-established reactive methyl radical, CH3, are based on a system of seven outer electrons in contrast to the eight outer electrons found in normal phosphorus molecules or ions. The phosphoranyl radical, RjP and the phosphonium radical anion RsP, are exceptional since they have nine outer electrons and no nitrogen analogues. Phosphinidene, PH (Uke nitrene NH) has only six outer electrons. 

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