First air stable tin(II) β-heteroarylalkenolate: Synthesis, characterization and application in chemical vapor deposition

A novel tin(II)-compound, bis(η2-N,O-2-[4,5-dimethyloxazolyl]-1,1,1-trifluoro-propen-2-olato)tin, SnII[(Me2C3NO)(CHCOCF3)]2 (1), was obtained by reacting Sn[N(SiMe3)2]2 with 2 M equivalents of the β-heteroarylalkenol, (Me2C3NO)(CHCOHCF3) (2). The molecular structures of ligand and the tin derivative were elucidated by single crystal X-ray diffraction and multi-nuclear NMR spectroscopic studies, which confirmed the monomeric nature and fourfold coordination of the tin(II) center with a pseudo-pyramidal geometry. The bidentate chelating mode of 2 imparted intriguingly high air stability to 1, which together with its high volatility make it an interesting precursor for the chemical vapor deposition (CVD) process. CVD of 1 on gold-coated Al2O3 substrates produced single crystalline SnO2 nanowires by vapor–liquid–solid growth mechanism. Transmission electron microscopy studies and X-ray diffraction data confirmed the high crystallinity of SnO2 nanowires possessing an average diameter of 90 nm.

Graphical abstractThe article features the synthesis and structural characterization of new fluorinated β-alkenolate ligand (Me2C3NO)(CHCOHCF3) and its tin(II) derivate. The introduction of fluorinated unit in the ligand framework endows remarkable air stability to the title compound. In the view of the above and high volatility of the tin(II) compound, the CVD experiments have also been carried out, which resulted in the formation of nanostructured tin oxide deposits.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis and characterization of a new fluorinated β-alkenolate ligand and its tin(II) derivative. ► Application of the tin(II) compound as first air stable CVD precursor to produce tin oxide nanowires. ► CVD process revealed no disproportionation reaction as known in tin(II) alkoxides.