Multiple Dynamic Anticounterfeiting Using Photochromic Luminescence Organic Cocrystals.

Photochromic and luminescent complexes are easy to imitate due to their single-signal output, resulting in a low encryption and anticounterfeiting level. Photochromic luminescence (PCL) complexes exhibit fluorescence and color-changing dual output, which provides additional safety and greatly improves anticounterfeiting security. However, it is challenging to overcome the competition between luminescence and the quenching effect of the photoinduced electron transfer (PET) process.

A novel viologen-based hybrid crystalline material for photochromic glass films, information storage and anti-counterfeiting.

Information storage and anti-counterfeiting are two very important applications of photochromic materials. Photochromic materials with both information storage and anti-counterfeiting should meet the requirements including fast coloration, good stability and reversibility, low storage cost, and practical application value. Herein, a novel viologen-based coordination polymer, Cd[(pbpy)(HBTC)Cl]·2HO (1) (pbpy = 1,1'-[1,4-phenylenebis-(methylene)]bis(4,4'-bipyridinium); HBTC = 1,3,5-benzenetricarboxylic acid), has been constructed.