Solid-State 31P NMR studies reveal that phosphinine ligands employed for the stabilisation of gold nanoparticles react in part during the synthesis, and that the particles are stabilised by a mixture of intact phosphinine units together with several other surface-bound species. The spectral data of these species are characteristic for phosphine-type donors although unambiguous structure assignment was as yet unfeasible. The spectral data of surface-bound phosphinines were verified by comparison with the spectrum of an authentic complex [(1)AuCl]. The metal-bound phosphinines in both the complex and the nanoparticles prefer η1(P)-coordination to a single metal atom, and the observation of splittings arising from coupling with 197Au (I = 3/2) nuclei indicates that these ligands are not mobile. The fraction of intact phosphinines on the nanoparticles drops with decreasing steric protection although the observed product distribution shows no simple relation with substituent patterns.
固态 31P NMR 研究显示,用于稳定
金纳米粒子的
膦配体在合成过程中发生了部分反应,粒子由完整的膦单元与其他几种表面结合物质的混合物稳定。这些物质的光谱数据具有膦类供体的特征,但目前还无法明确确定其结构。通过与真实复合物 [(1)AuCl] 的光谱进行比较,验证了表面结合膦的光谱数据。络合物和纳米粒子中与
金属结合的膦都倾向于与η1(P)-单个
金属原子配位,观察到与 197Au (I = 3/2) 原子核耦合产生的分裂表明这些
配体不具有流动性。虽然观察到的产物分布与取代基模式没有简单的关系,但纳米粒子上完整膦的比例随着立体保护的减少而下降。