Ligand exchange was triggered at toluene/water emulsion interface between homogeneous gold nanoparticles (Au NPs) with triphenylphosphine (PPh 3 ) and D-penicillamine (D-PA), resulted in amphiphilic Janus Au NPs with both phosphine and thiolate ligands. TEM and XRD analyses indicate that the product is composed of Au nanocrystals in an average diameter of about 3.7 nm. XPS, FTIR, Raman, and 1 H NMR analyses demonstrate that the Au NPs are protected with hydrophilic D-PA molecules and lipophilic PPh 3 ligands in a molecular ratio of ca. 1.8. The NOESY analysis and contact angle measurement further suggest that the D-PA and PPh 3 molecules are spontaneously separated to form compartmentalized hydrophilic and lipophilic regions on the individual Au NPs, which exhibit good catalytic performance and recyclability on the reduction of 4-nitrophenol. The results demonstrate that amphiphilic Janus Au NPs can be synthesized by partly exchange of PPh 3 with D-PA at toluene/water emulsion interface and are potentially applicable for other phosphine/thiolate pairs to modify Au NPs.

中文翻译：

---

在甲苯/水乳液界面通过配体交换合成三苯基膦和 D-青霉胺稳定的两亲 Janus 金纳米粒子

在均质金纳米粒子 (Au NPs) 与三苯基膦 (PPh 3 ) 和 D-青霉胺 (D-PA) 之间的甲苯/水乳液界面触发配体交换，产生具有膦和硫醇盐配体的两亲 Janus Au NPs。TEM 和 XRD 分析表明该产品由平均直径约为 3.7 nm 的 Au 纳米晶体组成。XPS、FTIR、拉曼和 1 H NMR 分析表明，Au NP 受到亲水性 D-PA 分子和亲脂性 PPh 3 配体的保护，分子比约为 1.8. NOESY 分析和接触角测量进一步表明 D-PA 和 PPh 3 分子自发分离，在单个 Au NPs 上形成分隔的亲水和亲油区域，这对 4-硝基苯酚的还原表现出良好的催化性能和可回收性。