Nitrogen-containing fused heterocycles as the structural fragments in calamitic liquid crystals

Pyrimidine as a Structural Fragment in Calamitic Liquid Crystals

“…Interestingly, pointing the nitrogens of two pyrimidine rings toward each other results in the disappearance of the smectic phase and the formation of the nematic phase, exhibiting higher meltingpoint and lower clearing temperatures in comparison with those of the corresponding derivative that has the nitrogens pointed in the same direction (compounds [4][5][6][7][8][9][10][11][4][5][6][7][8][9][10][11][12].…”

“…In continuation of our study of the structure-property relationships in nitrogen-containing liquid crystals (see, for example, the previous publications [1][2][3][4]), we present here a review that examines in some detail the effect of the introduction of the pyrimidine ring into the molecular structure of calamitic liquid crystals on the appearance of the mesophases and their physicochemical and electro-optical properties. When possible, the properties of the pyrimidine derivatives are compared with those of the corresponding nitrogen-containing six-membered ring derivatives and 1,4-phenylene derivatives.…”

Sulfur as a Structural Element in Calamitic Liquid Crystals. 2 Terminal, Linking, Axial and Lateral Substitutions. 3 Sulfur-Containing Rings

“…In continuation of our study of the structure-property relationships in sulfurcontaining liquid crystals (see, for example, the previous publications [1][2][3][4][5][6]) we present here a review that examines in some detail the effect of the introduction of the sulfur atom into the molecular structure of calamitic liquid crystals on the appearance of the mesophases and their physico-chemical properties. When possible, the properties of the sulfur derivatives will be compared with those of the corresponding hydrocarbon and oxygen derivatives.…”

Liquid-Crystalline Oxygen-Containing Heterocyclic Derivatives. 2 Six-Membered Rings Containing Oxygen as Structural Fragments in Liquid Crystals

“…In continuation of our study of the structure-property relationships in oxygencontaining liquid crystals (see, for example, the previous publications [1][2][3][4][5]) we present here a review that examines in some detail the effect of the introduction of the oxygen-containing six-membered rings and based on them systems into the molecular structure of liquid crystals on the appearance of the mesophases and their physico-chemical properties. When possible, the properties of the oxygen-containing derivatives will be compared with those of the corresponding hydrocarbon and heterocyclic derivatives.…”