Low-Dimensional Organic Lead Halides with Organic–Inorganic Collaborative Luminescence Regulated by Anion in Dimension

Low-dimensional
(LD) organic-metal halides (OMHs) have been extensively
investigated because of their excellent optical properties. However,
the rational synthetic control (dimension regulation) of LD-OMHs has
not yet been established well. The effect of organic cations on the
luminescence also remains unexplored. Here, we designed a double-chain
ammonium salt 1 with two amine functional groups. Using
hydrogen bonding between −N–H3 protons and
halogen ions synthesized zero-dimensional (0D) OMH C12H30N4Pb2Br8 (2). Furthermore, through introducing other ionic interactions to regulate
the dimension of OMHs, we obtained one-dimensional (1D) OMH C12H30N4Pb2Cl7.5Br0.5 (3) by anion exchange of 2. Through the in-depth analysis of their crystal structure, it is
understood that the design of organic cations and the exchange of
anions can regulate the dimension of OMHs through the change of hydrogen
bonds in the structure. This sets a foundation for the formation of
a synthesis mechanism for LD-OMHs and effective regulation of OMHs
dimension. Through crystal structure analysis, experiments, and theoretical
calculations, this work proves that the emission of 2 is not dominated by a single factor of organic cations or metal
halogen octahedrons but by the interaction of organic cations and
metal octahedrons. Moreover, the 1D-OMH 3 shows tunable
emissions from blue to white light under varying excitation wavelengths,
which provides a foundation for expanding the application of OMHs.

低维(LD)有机金属卤化物(OMHs)因其优异的光学性能而被广泛研究。然而，低维有机金属卤化物的可控合成（维度调控）尚未完全成熟，有机阳离子对其发光性能的影响也仍有待探究。本研究设计了一种含两个氨基官能团的双链铵盐1。通过利用−N–H₃质子与卤离子之间的氢键，合成得到零维(0D)有机金属卤化物C₁₂H₃₀N₄Pb₂Br₈（化合物2）。进一步通过引入其他离子相互作用来调控有机金属卤化物的维度，我们借助化合物2的阴离子交换反应，制备得到一维(1D)有机金属卤化物C₁₂H₃₀N₄Pb₂Cl₇.₅Br₀.₅（化合物3）。通过对二者晶体结构的深入解析，研究表明：有机阳离子的设计与阴离子的交换可通过改变结构内的氢键作用，实现对有机金属卤化物维度的调控，这为低维有机金属卤化物的合成机制构建及维度的精准调控奠定了基础。本研究通过晶体结构解析、实验与理论计算证实，化合物2的发光并非仅由有机阳离子或金属卤八面体单一因素主导，而是由二者的协同相互作用决定。此外，一维有机金属卤化物3在不同激发波长下展现出从蓝光到白光的可调谐发光，这为有机金属卤化物的应用拓展提供了基础。