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.

通过在恒定压力下测定升华起始温度（Tsub），建立了卤素配体变化对X–Au–L型（X = Cl, Br, I；L = CNtBu, CNMe, PMe3, P(NMe2)3, P(OCH2CF3)3）金(I)配合物挥发趋势的研究。在每一系列的异氰酸酯配合物中，随着卤素原子半径的增大，Tsub逐渐降低，使得碘化物配合物展现出最高的挥发性。对于膦和膦酰胺配合物而言，氯和溴的Tsub值相近，其中溴略高，但碘化物配合物依然是三者中最易挥发的。挥发趋势与固态结构中金–金键长和聚集模式的变化密切相关。对于P(OCH2CF3)3配合物，熔化发生在升华之前，但碘化物配合物的挥发性仍高于溴化物。这些趋势对于这些配合物在电子束诱导沉积和化学气相沉积中的应用具有重要意义，因为这些工艺对前驱体的挥发性要求较高。