Synthesis and crystal structures of cyclodiazastannoxides fused cyclopentadienyl M-Sn (M = Mo, W) bonded organometallic heterocycle

The condensation reaction of CH₃COC₅H₄M(CO)₃SnCl₃ (M = Mo or W) with PyCONHNH₂ (Py = 2,3,4-pyridyl or 2-pyridylmethyl) in mild conditions yields cyclodiazastannoxides fused cyclopentadienyl M-Sn bonded organometallic heterocycle {μ-C₅H₄(CH₃)CN-NC(O)PyH]M(CO)₃SnCl₃}. The similar reaction of CH₃COC₅H₄M(CO)₃SnCl₃ with ArCONHNH₂ (Ar = 2-furanyl) gives complexes μ-C₅H₄(CH₃)CN-NC(O)Ar]M(CO)₃SnCl₂(H₂O), in which the water molecule can be replaced by other N-donor ligands, such as pyridine or 4,4-bipyridine. Arene-bridged organometallic heterocyclic complexes μ-{C₅H₄(CH₃)CN-NC(O)]₂C₆H₄}{M(CO)₃SnCl₂(Solvent)}₂ have also been prepared by the reaction of CH₃COC₅H₄M(CO)₃SnCl₃ with terephthaloyl hydrazine. In these new organometallic heterocyclic complexes, it seems that the tin atom prefers to be six-coordinate through absorbing the chloridion or solvent molecules.