吡咯烷酮对Au_n(n=2～10)团簇保护机制的第一性原理研究

First-principles study of the protection of pyrrolidone towards Au_n(n=2-10)clusters

使用密度泛函理论方法研究了Aun(n=2-10)团簇与保护配体吡咯烷酮(pyrrolidone,PRD)之间的相互作用.经过在TPSS/def2-TZVP水平上的优化和遴选,得到较为稳定的Aun∶PRD(n=2-10)构型.计算表明:PRD与Au团簇间存在物理吸附作用,PRD中的O与Au相互间形成较弱的Au—O键,在二者之间存在少量的电荷转移,PRD作为电子供体,Au团簇为电子受体.表明PRD不仅能吸附在Aun(n=2-10)团簇表面阻止其聚集,而且能够影响其电子性质,但这种影响较小.这正是选择PRD作为Aun保护配体的结构基础.

The interaction between pyrrolidone （PRD） and Aun （n=2-10） is investigated by means of density functional theory calculations. The geometries of Aun ： PRD（n=2-10） isomers are constructed and then screened at the TPSS/def2-TZVP level. Our calculations reveal that a physisorption exists between PRD and Aun with small amount of charge transfer from PRD to Aun. PRD not only serves a protector that prevents Aun from aggregation, but also affects the electronic properties of Aun, but the influence is relatively small.