A Selective Synthesis of the 1,3,4-Triphospholide Anion

[Mg 2 (μ-Cl) 3 (THF) 6 ][2,5-(C t Bu) 2 -1,3,4-P 3 ] and K[2,5-(C t Bu) 2 -1,3,4-P 3 ] are formed quantitatively from reduction of the tricyclic-triphosphorus compound ClP 3 (C t Bu) 2 with Mg or K; the mechanistic insights gained from these studies lead to a new and “economic” synthesis of the [2,5-(C t Bu) 2 -1,3,4-P 3 ] - anion from the phosphalkyne t BuC⋮P.