Efficient and practical method for the synthesis of hydrophobic azines as liquid crystalline materials

Mesomorphism behaviour and photoluminescent properties of new asymmetrical 1,2-di(4-alkoxybenzylidene)hydrazines

“…n H, n = 1-10, 16 or 18) (Series II, 4a-l) were prepared according to our previous work. [19][20][21] The purity of the prepared compounds was determined by thin-layer chromatography using silica gel as stationary phase and n-hexane/ethyl acetate (16:1) as eluent. Column chromatography was carried out using silica gel 60 (200-300 mesh).…”

“…Then, the nematic thread-like texture appeared as a result of joining these droplets together. [18][19][20][21]23 The enthalpy of the clearing point of asymmetrical azine compounds Series III (5a-l) was in the range 0.93-2.09 kJ mol −1 . This further confirmed the nematic to isotropic transition.…”

“…This further confirmed the nematic to isotropic transition. [18][19][20][21][23][24][25] The DSC thermograms of all compounds of Series III (5a-l) (except 5a and 5b) displayed a couple of intense melting peaks (which can be attributed to transitions from different states of crystalline solid into nematic, passing through a smectic mesophase) followed by a weak clearing peak detected at higher temperatures which was mainly due to the transition from nematic mesophase to the isotropic liquid. Two examples, 5a and 5i, are shown in Figure 3.…”

“…[7][8][9][10][11][12][13][14][15][16][17][18] We are interested in the synthesis of azine-type derivatives as photoluminescent mesogenic materials following a simple and practical method. In very recent reports we have described the preparation, liquid crystal and photoluminescent properties of 1,2-bis[4-(n-alkoxy)benzylidene]hydrazines (n-alkoxy = O(CH 2 ) n H, n = 1-10, 12, 16 or 18), a symmetrical series of 1,2-disubstituted hydrazines 19…”

Synthesis of New Liquid-Crystalline Compounds Based on Terminal Benzyloxy Group: Characterization, DFT and Mesomorphic Properties

“…The hard core of numerous low molar mass calamitic mesogenic compounds usually consists of many 1,4-disubstituted phenyl rings, some of which may or may not have lateral substituents, the terminals on one or both sides are linked to a long flexible hydrocarbon chain (with or without halo substituents). By making structural changes to LCs and/or adding fluorine or other small-size lateral substituents to the rigid core, one can change how mesomorphic they are [32]. Thermotropic LCs are mesogenic compounds whose mesomorphism is solely dependent on changes in the ambient temperature.…”