Highly luminescent crystals of a novel linear π-conjugated thiophene–phenylene co-oligomer with a benzothiadiazole fragment

The synthesis, growth from solutions and structure of crystals of a new linear thiophene–phenylene co-oligomer with a central benzothiadiazole fragment with a conjugated core, (TMS-2T-Ph)2-BTD, are presented. Single-crystal samples in the form of needles with a length of up to 7 mm were grown and their crystal structure was determined at 85 K and 293 K using single-crystal X-ray diffraction. The conformational differences between the crystal structures are insignificant. The parameters of melting and liquid crystalline phase transitions of (TMS-2T-Ph)2-BTD were established using differential scanning calorimetry and the thermal stability of the crystals was investigated using thermogravimetric analysis. The optical absorption and photoluminescence spectra of the solutions and crystals of (TMS-2T-Ph)2-BTD were obtained, and the kinetics of their photodegradation under the action of UV radiation were studied.

Термодинамическая модель зародышеобразования кристаллов n-терфенила с анизотропией поверхностной энергии на межфазной границе жидкость-воздух

An analysis of the change in the Gibbs free energy ∆G upon the formation of a flat nucleus of a p-terphenyl crystal at the liquid – air interface is presented, taking into account the anisotropy of the surface energy of the faces. The surface energy values of the p-terphenyl crystal faces were calculated by the atomic force field method OPLS, based on structural data. Experimental information on crystal growth from solutions and their surface properties was used to analyze the model.

Рост из растворов кристаллов новых линейных фенилен-оксазольных олигомеров с центральным бензотиадиазаольным фрагментом

The results on solubility and growth from solutions of organic crystals of novel co-oligomers with the same pi-conjugated core consisting of benzothiadiazole, phenylene and oxazole fragments with different terminal substituents are reported. Melting parameters and thermal stability during heating was investigated by DSC and TGA methods.