Deposition of SnS Thin Films from Sn(II) Thioamidate Precursors

Abstract

Two thioamide pro-ligands, R1N(H)C(=S)R2 (R1 = t-Bu, R2 = i-Pr and R1 = i-Pr, R2 = i-Pr), were synthesized by treatment of the corresponding amides with Lawesson’s reagent. Reactions of [Sn{N(SiMe3)2}2] with two molar equivalents of each thioamide pro-ligand yielded the tin(II) thioamidate species, bis(2-methyl-N-(1-methylethyl)-propanethioamide)tin(II) and bis[N-(1,1-dimethylethyl)-2-methyl-propanethioamide]tin(II). Both of the new tin compounds have been characterised by 1H, 1C and 119Sn NMR spectroscopy and elemental analysis. In addition, the solid-state structure of bis(2-methyl-N-(1-methylethyl)-propanethioamide)tin(II) has been determined through a single crystal X-ray diffraction analysis and shown to display a monomeric constitution in which the tin(II) centre occupies a distorted pseudo-square pyramidal geometry defined by the N2S2 donors and the stereochemically active lone pair. Both tin(II) derivatives have been assessed for their potential as single source precursors to SnS by TGA and by NMR...