LAUSR

Hexamethyldisilazide-1,3-diisopropylimidazolidine-2-ylidenegold(I) (1) is used to deposit gold microplates with (111) faces. In the absence of any secondary vapor-phase surfactant, these plates show secondary nucleation and growth of gold metal nanoparticles on the (111) faces. When tetrahydrothiophene (THT) is used as a secondary, vapor-phase surfactant, plate size increases, and secondary nucleation is controllable by temperature. Deposition of gold microplates at 370 °C using a 45 mTorr overpressure of THT shows the best experimental results, growing 20 µm2 plateaus with no apparent secondary nucleation. Computational modelling demonstrates that THT is a stronger surfactant than the carbene ligand (from the gold precursor) due to steric hindrance from the alkyl groups present in the carbene ligand.