Reduction of Cx2NPCl2(Cx = cyclohexyl) with LiAlH4 gives Cx2NPH2 as an isolable air-sensitive liquid which can be converted into the relatively stable metal carbonyl complexes Cx2NPH2M(CO)5(M = Cr and W) and Cx2NPH2Fe(CO)4; the 2,2,6,6-tetramehtylpiperidiono derivative [graphic omitted]PH2 is also isolable and the diisopropylamino derivative Pri2NPH2 has been detected in solution by 31P n.m.r. spectroscopy