Combining Theory and Experiment to Get Insight into the Amorphous Phase of Luminescent Mechanochromic Copper Iodide Clusters

作者：Raquel Utrera‐Melero, Brendan Huitorel, Marie Cordier, Jean‐Yves Mevellec, Florian Massuyeau, Camille Latouche, Charlotte Martineau, Sandrine Perruchas · 发表于：Inorganic Chemistry · 年份：2020 · DOI：10.1021/acs.inorgchem.0c01967 · 被引用次数：58 · 研究领域：Nanocluster Synthesis and Applications、Luminescence and Fluorescent Materials、Lanthanide and Transition Metal Complexes

In the field of stimuli-responsive luminescent materials, mechanochromic compounds exhibiting reversible emission color changes activated by mechanical stimulation present appealing perspectives in sensor applications. The mechanochromic luminescence properties of the molecular cubane copper iodide cluster [Cu 4 I 4 [PPh 2 (C 6 H 4 –CH 2 OH)] 4 ] ( 1 ) are reported in this study. This compound can form upon melting an amorphous phase, giving an unprecedented opportunity to investigate the mechanochromism phenomenon. Because the mechanically induced crystalline-to-amorphous transition is only partial, the completely amorphous phase represents the ultimate state of the mechanically altered phase. Furthermore, the studied compound could form two different crystalline polymorphs, namely, [Cu 4 I 4 [PPh 2 (C 6 H 4 –CH 2 OH)] 4 ]·C 2 H 3 N ( 1·CH 3 CN ) and [Cu 4 I 4 [PPh 2 (C 6 H 4 –CH 2 OH)] 4 ]·3C 4 H 8 O ( 1·THF ), allowing the establishment of straightforward structure–property relationships. Photophysical and structural characterizations of 1 in different states were performed, and the experimental data were supported by theoretical investigations. Solid-state NMR analysis permitted quantification of the amorphous part in the mechanically altered phase. IR and Raman analysis enabled identification of the spectroscopic signatures of each state. Density functional theory calculations led to assignment of both the NMR characteristics and the vibrational bands. Rationalization of...