Bujak Piotr, Wróbel Zbigniew, Penkala Mateusz, Kotwica Kamil, Kmita Angelika, Gajewska Marta, Ostrowski Andrzej, Kowalik Patrycja, Pron Adam
Faculty of Chemistry , Warsaw University of Technology , Noakowskiego 3 , 00-664 Warsaw , Poland.
Institute of Organic Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland.
Inorg Chem. 2019 Jan 22;58(2):1358-1370. doi: 10.1021/acs.inorgchem.8b02916. Epub 2019 Jan 4.
The presented research is focused on the synthesis of alloyed Ag-In-Zn-S colloidal nanocrystals from a mixture of simple metal precursors such as AgNO, InCl, zinc stearate combined with 1-dodecanethiol (DDT), 1-octadecene (ODE), and sulfur dissolved in oleylamine (OLA). In particular, the focus is on the effect of the solvent (ODE vs 1,2-dichlorobenzene (DCB)) and the type of sulfur precursor (S/OLA vs S/ n-octylamine (OCA)) on the metal precursors reactivates and on the chemical composition, crystal structure, and luminescent properties of the resulting nanocrystals. The replacement of ODE by DCB as a solvent lowers the reactivity of metal precursors and results in a 3-fold decrease of the photoluminescence quantum yields (Q.Y.) values (from 67% to 21%). This negative effect can be fully compensated by the use of S/OCA as a source of sulfur instead of S/OLA (Q.Y. increases from 21% to 64%). NMR studies of the isolated organic phase indicate that the S/OLA precursor generates two types of ligands being products of ( Z)-1-amino-9-octadecene (OLA) hydrogenation. These are "surface bound" 1-aminooctadecane (CHNH) and crystal bound, i.e., alkyl chain covalently bound to the nanocrystal surface via surfacial sulfur (CH-NH-S crystal). Highly luminescent Ag-In-Zn-S nanocrystals exhibit a cation-enriched (predominantly indium) surface and are stabilized by a 1-aminooctadecane ligand, which shows more flexibility than OLA. These investigations were completed by hydrophilization of nanocrystals obtained via exchange of the primary ligands for 11-mercaptoundecanoic acid, (MUA) with only a 2-fold decrease of photoluminescence Q.Y. in the most successful case (from 67% to 31%). Finally, through ligand exchange, an electroactive inorganic/organic hybrid was obtained, namely, Ag-In-Zn-S/7-octyloxyphenazine-2-thiol, in which its organic part fully retained its electrochemical activity.
所呈现的研究聚焦于由简单金属前驱体混合物合成合金化的Ag-In-Zn-S胶体纳米晶体，这些前驱体包括AgNO₃、InCl₃、硬脂酸锌，并与1-十二烷硫醇（DDT）、1-十八烯（ODE）以及溶解在油胺（OLA）中的硫混合。特别地，重点在于溶剂（ODE与1,2-二氯苯（DCB））以及硫前驱体类型（S/OLA与S/正辛胺（OCA））对金属前驱体反应活性以及所得纳米晶体的化学成分、晶体结构和发光性能的影响。用DCB替代ODE作为溶剂会降低金属前驱体的反应活性，并导致光致发光量子产率（Q.Y.）值降低3倍（从67%降至21%）。通过使用S/OCA作为硫源而非S/OLA，这种负面影响可得到完全补偿（Q.Y.从21%增至64%）。对分离出的有机相的核磁共振研究表明，S/OLA前驱体产生两种类型的配体，它们是(Z)-1-氨基-9-十八烯（OLA）氢化的产物。这些是“表面结合”的1-氨基十八烷（CH₃(CH₂)₁₆NH₂）和晶体结合的，即烷基链通过表面硫与纳米晶体表面共价结合（CH₃(CH₂)₁₆-NH-S晶体）。高发光性的Ag-In-Zn-S纳米晶体呈现富阳离子（主要是铟）表面，并由1-氨基十八烷配体稳定，该配体比OLA表现出更大的灵活性。通过将主要配体交换为11-巯基十一烷酸（MUA）对纳米晶体进行亲水化处理，在最成功的情况下光致发光Q.Y.仅降低2倍（从67%降至31%），从而完成了这些研究。最后，通过配体交换获得了一种电活性无机/有机杂化物，即Ag-In-Zn-S/7-辛氧基吩嗪-2-硫醇，其中其有机部分完全保留了其电化学活性。
