Concise access to iminophosphonamide stabilized heteroleptic germylenes: chemical reactivity and structural investigation

Abstract

The influence of a sterically demanding iminophosphonamide ligand, [(2,6-iPr₂C₆H₃N)P(Ph₂)(NtBu)]H (LH), on the synthesis and stability of a heteroleptic germylene monochloride, [(2,6-iPr₂C₆H₃N)P(Ph₂)(NtBu)]GeCl (1), and its reaction chemistry has been discussed. Complex 1 behaves as a Lewis base to form an adduct with Fe(CO)₄, namely [(2,6-iPr₂C₆H₃N)P(Ph₂)(NtBu)]Ge(Cl)Fe(CO)₄ (2). Reaction of 1 with KOtBu or AgOSO₂CF₃ affords Ge(II) compounds, [(2,6-iPr₂C₆H₃N)P(Ph₂)(NtBu)]GeR (R = OtBu (3), OSO₂CF₃ (4)). Treatment of complex 1 with elemental sulfur or selenium leads to heavier analogues of germaacid chlorides, [(2,6-iPr₂C₆H₃N)P(Ph₂)(NtBu)]Ge(E)Cl (E = S (5), Se (6)). Similarly, compound 3 on reaction with elemental sulfur or selenium produces heavier analogues of germaesters, [(2,6-iPr₂C₆H₃N)P(Ph₂)(NtBu)]Ge(E)OtBu (E = S (7), Se (8)). Complexes 1–8 were characterized using multinuclear NMR and EI-MS, and solid state structures of complexes 1–3, 5 and 8 have been elucidated using single crystal X-ray diffraction.