Thermo‐ and Mechano‐Triggered Luminescence ON/OFF Switching by Supercooled Liquid/Crystal Transition of Platinum(II) Complex Thin Films

Abstract

Trihexyltetradecylphosphonium (P6,6,6,14) salts of luminescent anionic Pt(II) complexes, (P6,6,6,14)[PtX2(ppy)] (X = Cl‐, Br‐; ppy = 2‐phenylpyridinate), are synthesized and photofunctional thin films with crystal/liquid bi‐stability are fabricated. In particular, the chloride complex provides a thin film exhibiting thermo‐ and mechano‐triggered luminescence ON/OFF switching at ambient temperature, which is based on the control of the supercooled liquid phase and bright luminescent crystalline phase. The photophysical properties of the complexes are investigated and compared with those of the bromide complex and tetra(n‐butyl)ammonium salts of the complexes. Furthermore, detailed photophysical analysis reveals a large contribution of the charge‐transfer character to the ligand‐centered 3π π* excited state, which results in intense phosphorescence in the crystal and high‐contrast luminescence ON/OFF by the phase transition of the chloride complex.

Elastic and bright assembly-induced luminescent crystals of platinum(ii) complexes with near-unity emission quantum yield

“…The radiative rate constant of 1 ( k r = 1.9 × 10 5 s −1 ; Table 1) is a typical value for the Pt-perturbed 3 ππ* emission of Pt( ii ) complexes. 1 e ,30 Although the Pt⋯Pt interactions were also negligible for crystal 2 , its emission band was found to be more complicated, consisting of several peaks ( λ max = 505, 533, and 636 nm). After comparing with the emission spectrum of the non-substituted [Pt(pic)(ppy)], 10 the emission band on the shorter-wavelength side ( λ max = 505, 533 nm) was attributed to a 3 ππ* emission.…”

A Thermoplastic Organic Metal Halide Scintillator

“…33−35 In addition, we noticed that molecular crystal materials exhibit rheological behavior due to the existence of hydrogen bonds. 36 Halogen atoms in transition metal halides, especially chlorine, which is relatively electronegative, provide favorable conditions for the formation of weak hydrogen bonds. 36 Hereby, it inspired us to develop a thermoplastic metal halide scintillator, which could provide a paintable strategy for X-ray imaging to solve the scattering problem.…”

“…36 Halogen atoms in transition metal halides, especially chlorine, which is relatively electronegative, provide favorable conditions for the formation of weak hydrogen bonds. 36 Hereby, it inspired us to develop a thermoplastic metal halide scintillator, which could provide a paintable strategy for X-ray imaging to solve the scattering problem. To the best of our knowledge, a recycled and plastic organic metal halide for radioluminescence has not been reported.…”

“…More recently, organometallic halides have been proved to be favorable competitors for the new generation of scintillators for their efficient radioluminescence and high stability. − In addition, we noticed that molecular crystal materials exhibit rheological behavior due to the existence of hydrogen bonds . Halogen atoms in transition metal halides, especially chlorine, which is relatively electronegative, provide favorable conditions for the formation of weak hydrogen bonds . Hereby, it inspired us to develop a thermoplastic metal halide scintillator, which could provide a paintable strategy for X-ray imaging to solve the scattering problem.…”

Magenta-Blue Electrofluorochromic Device Incorporating Eu(III) Complex, Anthracene Derivative, and Viologen Molecule

“…Stimuli-responsive photofunctional materials which alter their optical properties in response to external stimuli have been a subject of growing interest. Their photophysical characteristics, such as light-absorption, light-emission, and light-scattering, are able to modulate in response to various triggers such as optical [ 1 , 2 , 3 , 4 , 5 ], thermal [ 6 , 7 , 8 , 9 , 10 , 11 ], mechanical [ 12 , 13 , 14 , 15 , 16 ], and electrical stimuli. Among them, electrochemical-responsive photofunctional molecules have attracted considerable attention since electrical inputs can be applied rapidly and repeatedly to the responsive systems.…”