Transition Metal Chemistry of Main Group Hydrazides, VI. New Directed Synthetic Strategies to Functionalized Heterocyclic Phosphorus(III) Hydrazides. First Examples of Crystal and Molecular Structures of [RPN(Me)N(H)]₂ (R = Et, Ph, and tBu)

The reactions of methylhydrazine with RPC1 2 (R = Et, t Bu, and Ph) produced the cyclic phosphorus (III) hydrazides (1,2,4,5,3,6‐tetrazadiphosphorinanes) [RPN(Me)N(H) 2 (R = Et, 1 ; (Ph, 2 ; t Bu, 3 ) in good yields. The 1 H‐and 31 P‐NMR spectroscopic analysis indicated that 1 exists in chair and boat conformations. However, it crystallizes in the chair conformation exclusively. The X‐ray crystallographic investigation of all the three cyclo ‐phosphorus hydrazides 1–3 confirms the existence of these compounds in the chair conformations in the solid state. The reaction of Mo(CO) 4 ‐(NHC 5 H 10 ) 2 with 1 and 2 gives the dinuclear Mo(0) complexes [{Mo(CO) 4 (NHC 5 H 10 )} 2 (μ‐[RPN(Me)N(H)] 2 }] (R = Et, 5 ; Ph, 6 ). Based on 1 H‐ and 31 P‐NMR spectroscopic data, a bridging dinuclear dimetallic formulation is proposed for 5 and 6 . The IR spectra indicate that the carbonyls are disposed in cis ‐geometry around the Mo(0) center.