High Volatile Antimony(III) Precursors for Metal Oxide Thin Film Deposition

We report the synthesis
and characterization of novel antimony(III)
complexes: Sb(mpa)3 (1), Sb(mmpa)3 (2), Sb(mdpa)3 (3), Sb(epa)3 (4), Sb(empa)3 (5),
and Sb(edpa)3 (6) (mpa = N-methoxypropanamide, mmpa = N-methoxy-2-methyl-propanamide,
mdpa = N-methoxy-2,2-dimethylpropanamide, epa = N-ethoxypropanamide, empa = N-ethoxy-2-methylpropanamide,
and edpa = N-ethoxy-2,2-dimethylpropanamide, via
a salt-elimination reaction with SbCl3 and sodium-substituted
carboxamide. The molecular structure of 6 revealed the
formation of a homoleptic conformer with a highly distorted pentagonal
bipyramidal geometry, as determined by X-ray crystallography. Thermogravimetric
analysis showed excellent volatility at elevated temperatures, with
complex 4 displaying the lowest residual mass of 0.16%
at 500 °C. For complexes 4, 5, and 6, the temperature at a vapor pressure of 1 Torr and the enthalpy
of vaporization were estimated to be 58, 64, and 45 °C and 83.31,
103.58, and 99.93 kJ/mol, respectively.