Synthesis, characterisation and thermal properties of Sn(ii) pyrrolide complexes

Abstract

SnO is a rare example of a stable p-type semiconductor material. Here, we describe the synthesis and characterisation of a family of Sn(II) pyrrolide complexes for future application in the MOCVD and ALD of tin containing thin films. Reaction of the Sn(II) amide complex, [{(Me₃Si)₂N}₂Sn], with the N,N-bidentate pyrrole pro-ligand, L¹H, forms the hetero- and homoleptic complexes [{L¹}Sn{N(SiMe₃)₂}] (1) and [{L¹}2Sn] (2), respectively, bearing the 2-dimethylaminomethyl-pyrrolide ligand (L¹). Reaction of [{(Me₃Si)₂N)}₂Sn] with the pyrrole-aldimine pro-ligands, L²H–L⁷H, results in the exclusive formation of the homoleptic bis-pyrrolide complexes [{L^2–7}₂Sn] (3–8). All complexes have been characterised by elemental analysis and NMR spectroscopy, and the molecular structures of complexes 1–5 and 8 are determined by single crystal X-ray diffraction. TG analysis and isothermal TG analysis have been used to evaluate the potential utility of these systems as MOCVD and ALD precursors.