Vapochromism associated with the changes in the molecular arrangement of organic crystals

Abstract

Exposure of yellow anhydrate organic crystals to water vapor gave red hydrate crystals with significant changes in the molecular arrangement.

Reversible on/off conformational switching of pentafluorobenzoyl amide triggered by acid vapor and sublimation

“…Herein, we describe an on/off-type amide conformational transformation in the crystalline state induced by HCl vapor in one direction and by sublimation with pumping to remove HCl in the other direction. Although some acid-responsive crystals have been reported, [13][14][15][16][17] most involve stacking changes or subtle geometry changes, rather than a drastic change of the stable conformation such as conversion between E and Z conformations. Thus, the fact that our molecular switch 3 (Fig.…”

Proton–electron-coupled functionalities of conductivity, magnetism, and optical properties in molecular crystals

“…[94][95][96][97][98][99][100][101][102] Although many vapochromic materials bearing H-bonds have been reported to date, they have also been understood merely by structural changes. 62,63,[103][104][105][106][107][108][109][110][111][112][113][114][115][116] The mechanisms reported thus far have only considered the electronic states of an isolated complex, ignoring intermolecular interactions. Thus, to the best of our knowledge, there have been no reports on vapochromism based only on proton-electron coupling in the solid state.…”

“…1,3,5,9,10 Chemical reactions via interfacial PCET have also been extensively studied. The chemical reaction on the Pt (111) surface and titanium dioxide (TiO 2 ) is important for the development of renewable energy conversion systems, such as solar fuel cells. 3,8 In addition to molecular PCET-induced chemical reactions in bio-systems, functionalities in solids have been widely studied in these years.…”

Powder Structure Analysis of Vapochromic Quinolone Antibacterial Agent Crystals

“…The reported mechanisms for the observed color changes include intermolecular interactions 16,17 such as charge transfer and π···π interactions, and a change in the molecular structure, such as 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 5 conformational change 18 or intramolecular H + transfer (Fig. S1).…”

“…On the other hand, only a few reports on vapochromic organic crystals are available. The reported mechanisms for the observed color changes include intermolecular interactions, , such as charge transfer and π···π interactions, and a change in the molecular structure, such as conformational change or intramolecular H + transfer (Figure S1). However, there are no general guidelines regarding how to achieve vapochromic organic materials, because the number of reported examples is so few and because known vapochromic molecules have no structural or chemical similarities.…”