A Room‐Temperature X‐ray‐Induced Photochromic Material for X‐ray Detection

Abstract

A color change: X-ray-induced photochromic species are rare and can be used for detection of X-rays. A highly robust X-ray-sensitive material with the discrete structure of a metal-organic complex has been found to show both soft and hard X-ray-induced photochromism at room temperature. A new ligand-to-ligand electron-transfer mechanism was proposed to elucidate this photochromic phenomenon.

Calix‐Like Metal–Organic Complex for High‐Sensitivity X‐Ray‐Induced Photochromism

“…Similar to the previous reports,2 this color change is caused by the generation of reduced ZnV radical cations. As shown in Figure 3 a, the original samples exhibit no EPR signal, but a noticeable single‐peak radical signal is observed and increased with prolonged X‐ray irradiation time.…”

“…The violet samples (cMOC‐1a and cMOC‐2a) are stable in air in a dark room for 2 days at ambient temperature followed by a slow reversion back to original color over 1 week in a refrigerator (−10 °C). They can be easily decolored by heating at 80 °C for less than 10 min in air or in an argon atmosphere, whereas other reported X‐ray‐induced photochromic systems need higher temperature and rigorous condition to be recovered 2. This reversible photochromic transformation can repeat for more than ten cycles by alternated X‐ray irradiation and heating, and no noticeable change of photochromic properties is observed.…”

Halogen Contacts‐Induced Unusual Coloring in BiIII Bromide Complex: Anion‐to‐Cation Charge Transfer via Br⋅⋅⋅Br Interactions

“…Moreover, although this class of compounds has been intensively studied for more than 100 years and can be considered as a “classic” of coordination chemistry, it continues to surprise the chemical community with novel unexpected features. Among the most recent examples are photochromism found in viologen‐containing chlorobismuthates and hybrid bromozincates, thermochromism of iodobismuthates, solvent‐induced color changes in porphyrinic halobismuthates, mechanochromic luminescence, photocatalytic activity, etc. Herein, we report a novel unforeseen phenomenon which was observed in the course of our studies of Bi III halide complexes (PHBs).…”

Flexible Viologen‐Based Porous Framework Showing X‐ray Induced Photochromism with Single‐Crystal‐to‐Single‐Crystal Transformation

“…Continuous radiation for 1h leads to totally blue color and more pronounced shift of the PXRD pattern that is consistent with simulated data from blm-Co-X single-crystal structure (Figure 4c,d). Continuous radiation for 1h leads to totally blue color and more pronounced shift of the PXRD pattern that is consistent with simulated data from blm-Co-X single-crystal structure (Figure 4c,d).…”