Acylhydrazones liquid crystals: effect of structure over thermal behaviour and molecular switching

Photoisomerization of a 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran analog dye: a combined photophysical and theoretical investigation

“…[1][2][3][4] The tunable optical and mechanical properties upon irradiation provided by the double-bond isomerization allow applications such as light-sensitive sensors and functional materials. [5][6][7] The NQN, CQN and CQC bonds are the most common photoswitchable groups in azobenzenes, 8,9 acylhydrazones, [10][11][12] and stilbenes 13 , respectively.…”

Photoisomerizable azobenzene star-shaped liquid crystals: bypassing the absence of hydrogen bonding

“…The discrepancy between a and L is regularly observed and typically attributed to a conjunction of factors like interdigitation, structure and chain folding due the system fluidity, which are also affected by the temperature. 21–23…”

“…The discrepancy between a and L is regularly observed and typically attributed to a conjunction of factors like interdigitation, structure and chain folding due the system fluidity, which are also affected by the temperature. [21][22][23] For compound OXA-Bn at 100 1C, besides the four peaks at lower angles, two broad diffractions are also observed at higher angles, at around 4.5 and 3.5 Å (Fig. 5A).…”

“…6B and C). 22,24,25 From the data extracted from the diffractogram and discussed above, the number of molecules (Z) that constitute each disk forming the Col h arrangement could be estimated employing the following equation Z = O3/2(a 2 .h.r.N)/Mm, where a is the lattice parameter; h is the height of each disk; N is the Avogadro number; r is the density of the compound (assumed to be 1 g cm À3 ); and Mm is the molar mass. 8,23,26 The results are summarized in Table 2 and, for compound OXA-Bn, Z is 1.7, which indicates that each disk is formed, on average, by around two molecules, as schematically illustrated in Fig.…”

Reaching Room‐Temperature Mesomorphism through Expansion of the Tristriazolotriazine Core with Alkoxybenzoate Units

“…Therefore, it was estimated for all liquid‐crystalline compounds in this work, how many molecules ( Z ) make up the disks that compose the Col h mesophases. This was estimated employing equation (1), [20a,21] where: a h is lattice parameter, h is the height of each disk, N the Avogadro's number, ρ the density of the materials, and M m the molar mass. For the calculations, it was assumed that the density ( ρ ) is 1 g cm −3 .…”