Department of Chemistry, Portland State University , 1719 SW 10th Avenue, Portland, Oregon 97201, United States.
J Am Chem Soc. 2017 Apr 26;139(16):5827-5835. doi: 10.1021/jacs.7b00158. Epub 2017 Apr 17.
Colloidal 3-mercaptopropionic acid (3-MPA) capped lead sulfide quantum dots were prepared in a variety of organic solvents stabilized with a quaternary ammonium halide salt. The stabilized colloids' optical properties were studied through optical absorption and emission spectroscopy and found to be dependent on both the concentration of a new ligand and stabilizer, and sample age. Nanocrystal ligand chemistry was studied through a combination of H NMR and two-dimensional Nuclear Overhauser Effect Spectroscopy (NOESY) which revealed full displacement of the original oleate ligand to form a dynamically exchanging ligand shell. The colloids were studied optically and via NMR as they aged and revealed a quantitative conversion of monomeric 3-mercaptopropionic acid to its dimer, dithiodipropionic acid (dTdPA).
胶体 3-巯基丙酸（3-MPA）封端的硫化铅量子点在各种有机溶剂中制备，并用季铵卤化物盐稳定。通过光学吸收和发射光谱研究了稳定胶体的光学性质，发现其取决于新配体和稳定剂的浓度以及样品的年龄。通过 H NMR 和二维核 Overhauser 效应光谱（NOESY）的组合研究了纳米晶配体化学，结果表明完全取代了原始油酸盐配体，形成了一个动态交换的配体壳。随着胶体的老化，通过 NMR 和光学研究发现，单体 3-巯基丙酸定量转化为其二聚体，二硫代二丙酸（dTdPA）。
