Recently, the exploitation of efficient fluorescent materials has
attracted substantial interest due to their potential application
in some areas such as in photoelectronic devices and sensors.1
Smart luminescent materials with stimuli-responsive emission
changing behaviors are of particular interest. Mechanochromic
materials, as a class of stimuli-responsive luminescentmaterials,
have also aroused a great deal of attention.2 High solid-state
emission and an obvious color contrast are very significant
for the application of mechanochromic fluorescent materials.3
However, the notorious aggregation caused quenching (ACQ)
effect results in a poor solid-state emission efficiency,4 which
largely hinders the development of mechanical stimuli-responsive
materials. Fortunately, in 2001, Tang et al. reported an unusual
and important phenomenon referred to as aggregation-induced
emission (AIE).5 Next, in 2002, Park et al. discovered the
aggregation-induced emission enhancement (AIEE) phenomenon,
which is caused by a synergistic effect of planarization and
J-aggregation.6 Both AIE and AIEE are effective methods to overcome
ACQ, achieving bright solid-state emission. To date, the
majority of luminescent materials exhibiting AIE and mechanochromic
behavior have been shown to be organic compounds.7
Meanwhile, a few luminogens based on zinc(II) and iridium(III)
complexes with AIE and mechanochromic properties have also