Mechanochromic luminescent property and anti-counterfeiting application of AIE-active cyclometalated platinum(II) complexes featuring a fused five-six-membered metallacycle

Toward Near-Infrared Emission in Pt(II)-Cyclometallated Compounds: From Excimers’ Formation to Aggregation-Induced Emission

“…The same pattern has been recorded in the emission of the chlorido precursors ( Figure S31 ). 3 , 4 , 8 , 12 , 16 , 36 The large Stokes shift and the quenching of the emission in the presence of oxygen support their phosphorescent emission assignment ( Table 1 ). The free L1 and L2 ligands present a broad emission band around 350 nm, which can be assigned to a fluorescent 1 π–π* IL transition that is not quenched by the presence of oxygen ( Figure S32 ), proving that the phosphorescent emission of these compounds is due to the perturbation from the platinum atom.…”

“…In the higher energy region (270–350 nm), all compounds present intense bands that can be attributed to 1 π–π* IL transitions of the cyclometallated 1,3-di­(2-pyridyl)­benzene, which are also recorded in the absorption of the free ligands L1 and L2 (Figure S30), overlapped, in some cases, with 1 π–π* IL transitions of the alkynyl aromatic moiety. In the lower energy region (350–450 nm), less intense bands are observed, which can correspond to mixed charge-transfer and ligand-centered character transitions, according to the literature. − ,,,,,− …”

“…In the lower energy region (350–450 nm), less intense bands are observed, which can correspond to mixed charge-transfer and ligand-centered character transitions, according to the literature. 7 − 9 , 12 , 16 , 26 , 28 , 34 − 36 …”

Self-Assembly of Mechanoluminochromic Ladder-Shaped Gold(I) Clusters Promoted Using Cooperative Aurophilicity

“…Mechanochromic materials are a promising category of “smart” materials with fluorescence properties that change in response to various external stimuli such as grinding, pressing, rubbing, or hydrostatic pressure . In particular, these materials can exhibit emission color changes visible to the naked eye, which greatly enhance their potential for applications in sensors, fluorescence switches, strain detection, storage, and anti-counterfeiting . Over the past few decades, the majority of mechanochromic luminescent species were based on organic molecules or dyes .…”

Circularly polarized luminescence of pinene-modified tetradentate platinum(II) enantiomers containing fused 5/6/6 metallocycles

“…Solvent effects on the absorption and emission of (−)- 1 are also examined (Figure S8). The lowest-energy absorption band is hypsochromically shifted with the increased polarity of the solvents, from 381 nm in toluene to 360 nm in methanol, verifying the character of a CT transition [ 65 , 66 , 67 ]. However, only minimal change (Δλ = 5 nm) of emission maximum can be perceived upon variation of the solvent polarity.…”