Quantifying Ligand Exchange on InP Using an Atomically Precise Cluster Platform
Quantifying Ligand Exchange on InP Using an Atomically Precise Cluster Platform
复制标题
DOI：
10.1021/acs.inorgchem.8b03524
复制
发表时间：
2019-02-18
影响因子：
4.6
通讯作者：
Cossairt, Brandi M.
中科院分区：
文献类型：
--
作者：
Ritchhart, Andrew;Cossairt, Brandi M.
胶体纳米颗粒的表面化学对其结构和功能都是固有的。因此，有必要表征胶体材料的表面，以合理地支持它们所能实现的任何合成、催化或转化机制。在这里，我们通过研究传统的稳定配体，包括羧酸盐，膦酸盐和硫醇盐的结合来表征胶体InP簇和量子点的表面性质。通过使用In 37 P20 X51（X =羧酸盐）簇物种作为一个理想的单分散和良好定义的起始支架，我们量化的表面交换平衡。使用定量H-1和P-31 NMR光谱，我们表明，1：1复分解型结合模型是不足以充分描述的表面动力学。特别是，对于高度可逆的羧酸盐配体交换的情况下，更详细的等温线的方法，使用两个站点，竞争模型是必要的。该模型用于解卷积L型和X型结合模式。我们还量化了在硫醇盐和膦酸盐体系中观察到的可逆和不可逆的配体交换反应。
The surface chemistry of a colloidal nanoparticle is intrinsic to both its structure and function. It is therefore necessary to characterize the surfaces of colloidal materials to rationally underpin any synthetic, catalytic, or transformative mechanisms they enable. Here we characterize the surface properties of colloidal InP clusters and quantum dots by examining the binding of traditional stabilizing ligands including carboxylates, phosphonates, and thiolates. By using the In37P20X51 (X = carboxylate) cluster species as an ideally monodisperse and well-defined starting scaffold, we quantify surface-exchange equilibria. Using quantitative H-1 and P-31 NMR spectroscopy, we show that 1:1 metathesis-type binding models are insufficient to fully describe the surface dynamics. In particular, for the case of the highly reversible carboxylate ligand exchange, a more detailed isotherm approach using a two-site, competitive model is necessary. This model is used to deconvolute L- and X-type binding modalities. We additionally quantify the reversible and irreversible ligand-exchange reactions observed in the thiolate and phosphonate systems.