Nicholas Aaron D, Barnes Francis H, Adams Daniel R, Webber Matthew S, Sturner Matthew A, Kessler Matthew D, Welch David A, Pike Robert D, Patterson Howard H
Department of Chemistry, University of Maine, Orono, ME 04469, USA.
Phys Chem Chem Phys. 2020 May 28;22(20):11296-11306. doi: 10.1039/d0cp00504e. Epub 2020 May 12.
We report on the vapochromic behavior of a series of homo- and heterometallic copper(i) iodide/silver(i) iodide nanoparticles when exposed to dimethyl sulfide (DMS) vapor. These systems show remarkable colorimetric sensing behavior via emission color upon DMS exposure, shifting from pink to green emission. Kinetics measurements of CuI/AgI nanoparticle reactions with DMS show a significant rate increase with increasing Ag(i) content. However, luminescence spectroscopy and X-ray diffraction of the post-exposure samples with varying Ag(i) content reveal that the luminophore is identical in all cases and contains no Ag(i) ions. To rationalize the experimental observations and determine the vapochromic response mechanism, molecular dynamic calculations were performed on model (111) cation-terminated surfaces of copper iodide crystals doped with variable amounts of silver. Computational studies indicate that heterometallic Cu/Ag systems have a stronger binding affinity towards DMS vapor molecules than homometallic CuI and that embedding of the DMS molecules into the surface is the primary intermediate by which the vapochromic response occurs.
我们报道了一系列同金属和异金属碘化亚铜/碘化银纳米颗粒在暴露于二甲基硫醚（DMS）蒸汽时的气致变色行为。这些体系在暴露于DMS时通过发射颜色表现出显著的比色传感行为，从粉色发射转变为绿色发射。碘化亚铜/碘化银纳米颗粒与DMS反应的动力学测量表明，随着银（I）含量的增加，反应速率显著提高。然而，对不同银（I）含量的暴露后样品进行的发光光谱和X射线衍射表明，在所有情况下发光体都是相同的，且不包含银（I）离子。为了合理解释实验观察结果并确定气致变色响应机制，对掺杂了不同量银的碘化铜晶体的模型（111）阳离子端接表面进行了分子动力学计算。计算研究表明，异金属铜/银体系对DMS蒸汽分子的结合亲和力比同金属碘化亚铜更强，并且DMS分子嵌入表面是发生气致变色响应的主要中间过程。
