New aspects of vapochromic metal complexes: Cooperative phenomena in functions and structures

Luminescence color change of [3,4-difluoro-2,6-bis(5-methyl-2-pyridyl)phenyl-κ3N,C1,N′]cyanidoplatinum(ii) by aggregation

“…Specifically, vapochromism, the color change upon exposure to solvent vapor, has been actively investigated for the past two decades. [15][16][17][18][19][20] Pt(II) complex crystal switching between two colors are expected to be applied for the easy and quick detection of small molecules. We have demonstrated the emission color tuning of Pt(N^C^N)Cl complexes by aggregation in the crystal state.…”

Reversible and Stepwise Single‐Crystal‐to‐Single‐Crystal Transformation of a Platinum(II) Complex with Vapochromic Luminescence

“…[2,13] However, a reversible SCSC transformation, followed by the absorption and desorption of molecules have been found only in limited systems. [14][15][16][17] Meanwhile, annealing processes conducted in a vapor atmosphere are found to improve the ordering in assembled structures of polymer systems and inorganic crystals. [18][19][20] In this context, elucidating the dynamic process of SCSC transformations in vapor-responsive molecular crystals is a challenging yet significant subject for the emergence of functions in highly ordered systems.…”

Theoretical Study on the Vapochromic Ni(II)–Quinonoid Complex: One-Dimensional Stacking Structure-Based Color Switching

“…6 In recent years, a new class of vapochromic metal complexes featuring spin states that change with their vapochromism has been reported. 5 This class of metal complexes is of particular interest owing to their potential applications in switching and memory devices. Pioneering works in this field have mainly focused on spin-crossover Fe(II) complexes in metal−organic frameworks, 7 in which the elongation of the lattice upon absorption of guest molecules changes the spin state.…”

“…Vapochromism refers to the change in color or luminescence of molecular crystals induced by changes in their crystal and electronic structures upon absorption of gas molecules. − Molecules and materials that exhibit vapochromism are important research targets owing to their potential applications in gas-sensing devices to detect volatile organic compounds, optical materials, and switching devices. Molecular crystals called soft crystals undergo changes in crystal structure or polymorphism following exposure to small external perturbations, such as gas molecules, light irradiation, and mechanical stimulation.…”

“…In recent years, a new class of vapochromic metal complexes featuring spin states that change with their vapochromism has been reported . This class of metal complexes is of particular interest owing to their potential applications in switching and memory devices.…”