Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
J Am Chem Soc. 2016 Feb 10;138(5):1510-3. doi: 10.1021/jacs.5b13214. Epub 2016 Jan 27.
Magic-sized nanoclusters have been implicated as mechanistically relevant intermediates in the synthesis of group III-V quantum dots. Herein we report the single-crystal X-ray diffraction structure of a carboxylate-ligated indium phosphide magic-sized nanocluster at 0.83 Å resolution. The structure of this cluster, In37P20(O2CR)51, deviates from that of known crystal phases and possesses a non-stoichiometric, charged core composed of a series of fused 6-membered rings. The cluster is completely passivated by bidentate carboxylate ligands exhibiting predominantly bridging binding modes. The absorption spectrum of the cluster shows an asymmetric line shape that is broader than what would be expected from a homogeneous sample. A combination of computational and experimental evidence suggests that the spectral line width is a result of multiple, discrete electronic transitions that couple to vibrations of the nanocrystal lattice. The product of reaction of this nanocluster with 1 equiv of water has also been structurally characterized, demonstrating site selectivity without a drastic alteration of electronic structure.
超小纳米团簇被认为是 III-V 族量子点合成过程中具有重要意义的机械中间产物。在此，我们报告了一种羧酸配体连接的磷化铟超小纳米团簇的单晶 X 射线衍射结构，分辨率为 0.83 Å。该团簇的结构（In37P20(O2CR)51）与已知晶体相不同，具有由一系列融合的 6 元环组成的非化学计量、带电核心。该团簇被二齿羧酸配体完全钝化，这些配体主要表现为桥接结合模式。团簇的吸收光谱显示出不对称的线形，比从均匀样品中预期的要宽。计算和实验证据的结合表明，谱线宽度是多个离散电子跃迁与纳米晶体晶格振动耦合的结果。该纳米团簇与 1 当量水反应的产物也进行了结构表征，证明了在不剧烈改变电子结构的情况下具有位点选择性。
