Heteroaryl‐Iminoalkoxide Complexes of Tin(II): Structure‐Property Relationships Governing Volatility and Thermal Stability

A family of seven heteroaryl‐iminoalkoxide Sn(II) complexes [HetC(H)C(R)OSn; Het = pyridine: R = Me, Et, i Pr, t Bu, Ad; Het = oxazole and imidazole: R = t Bu] have been synthesized by reaction of [Sn{N(SiMe 3 ) 2 } 2 ] with the corresponding pro‐ligands in toluene. Variation of both the heteroarene donor and alkyl substituent afforded structurally related pyridyl‐ and oxazolyl‐derived monomeric complexes with four‐coordinate geometries, based on enol tautomer complexation. In contrast, the imidazolyl analog exhibits a coordination mode arising from ketone tautomer complexation. Suitability of the thermal properties of the Sn(II) complexes for application in thin‐film vapor deposition (e.g., ALD and MOCVD) was assessed by (isothermal)‐thermogravimetric analysis [(IT)‐TGA]. The complexes displayed moderate volatility and good thermal stability (>200 °C), with all complexes leaving low residual masses (0%–10%). Based on the best‐performing pyridyl Sn(II) complex (R = t Bu, 4 ), which displayed a volatilization onset of 200 °C and negligible residual mass (0%), the corresponding Li(I), Ge(II) and Pb(II) complexes were also prepared, characterized and thermally assessed.