A paramagnetic WIII alkyne complex bearing free terminal diphenylphosphino groups at the side-on coordinated alkyne was synthesized using a stepwise template strategy. This moderately stable metal supported open shell diphosphine shows an unprecedented spontaneous splitting of nitric oxide providing a WII-η2-C2{P(NH2)Ph2}{P(O)Ph2}+ complex featuring an amino phosphonium and a phosphine oxide substituent.