Halide Effects on the Sublimation Temperature of X–Au–L Complexes: Implications for Their Use as Precursors in Vapor Phase Deposition Methods

Trends in volatility with changes in the halide ligand were established for gold­(I) complexes of the type X–Au–L [X = Cl, Br, I; L = CNtBu, CNMe, PMe3, P­(NMe2)3, P­(OCH2CF3)3] by determining the temperatures for the onset of sublimation (Tsub) at a fixed pressure. Within each series of isocyanide complexes, Tsub decreases with increasing atomic radius of the halide, making the iodide complex the most volatile. For the phosphine and phosphoramidate complexes, the chloride and bromide have similar Tsub values with the bromide slightly higher, but the iodide complex is again the most volatile of the three. The trends in volatility can be correlated to variation in Au–Au bond distances and aggregation patterns in the solid state structures. For the P­(OCH2CF3)3 complexes, melting occurred before sublimation, but the iodide complex was still more volatile than the bromide. These trends have implications for the use of these complexes in electron beam induced deposition and chemical vapor deposition, for which precursor volatility is important.

通过测定固定压力下的升华起始温度（Tsub），明确了X-Au-L型金(I)配合物（X=Cl、Br、I；L=CNtBu、CNMe、PMe3、P(NMe2)3、P(OCH2CF3)3）的挥发性随卤配体变化的趋势。在每一类异氰基配合物中，Tsub随卤原子原子半径的增大而降低，使得碘化物配合物的挥发性最强。对于膦配体及磷酰胺类配合物，氯化物与溴化物的Tsub值相近，溴化物略高，但碘化物仍是三者中挥发性最强的。该挥发性趋势可与固态结构中Au-Au键长变化及聚集模式相关联。对于P(OCH2CF3)3配合物，其会在升华前发生熔融，但碘化物配合物的挥发性仍强于溴化物。上述挥发性趋势对这类配合物在电子束诱导沉积及化学气相沉积中的应用具有参考价值，而前驱体挥发性是该两类沉积技术的关键参数。