Crystals of 4,7-Di-2-thienyl-2,1,3-benzothiadiazole and Its Derivative with Terminal Trimethylsilyl Substituents: Synthesis, Growth, Structure, and Optical-Fluorescent Properties
Valery A. Postnikov,
Georgy A. Yurasik,
Artem A. Kulishov,
Timofei A. Sorokin,
Maria S. Lyasnikova,
Nataliya I. Sorokina,
Maxim S. Skorotetcky,
Vlada V. Popova,
Lev L. Levkov,
Oleg V. Borshchev,
Evgeniya A. Svidchenko,
Nikolay M. Surin,
Sergey A. Ponomarenko
Affiliations
Valery A. Postnikov
Shubnikov Institute of Crystallography, FSRC “Crystallography and Photonics” of Russian Academy of Sciences, Moscow 119333, Russia
Georgy A. Yurasik
Shubnikov Institute of Crystallography, FSRC “Crystallography and Photonics” of Russian Academy of Sciences, Moscow 119333, Russia
Artem A. Kulishov
Shubnikov Institute of Crystallography, FSRC “Crystallography and Photonics” of Russian Academy of Sciences, Moscow 119333, Russia
Timofei A. Sorokin
Shubnikov Institute of Crystallography, FSRC “Crystallography and Photonics” of Russian Academy of Sciences, Moscow 119333, Russia
Maria S. Lyasnikova
Shubnikov Institute of Crystallography, FSRC “Crystallography and Photonics” of Russian Academy of Sciences, Moscow 119333, Russia
Nataliya I. Sorokina
Shubnikov Institute of Crystallography, FSRC “Crystallography and Photonics” of Russian Academy of Sciences, Moscow 119333, Russia
Maxim S. Skorotetcky
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Vlada V. Popova
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Lev L. Levkov
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Oleg V. Borshchev
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Evgeniya A. Svidchenko
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Nikolay M. Surin
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Sergey A. Ponomarenko
Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences, Moscow 117393, Russia
Among short donor–acceptor molecules with a central benzothiadiazole fragment, 4,7-di-2-thienyl-2,1,3-benzothiadiazole (T-BTD) is one of the most well-known compounds, valued for its photophysical and semiconductor properties. We have synthesized a derivative of 4,7-di-2-thienyl-2,1,3-benzothiadiazole with trimethylsilyl end-substituents, 4,7-bis(5-(trimethylsilyl)thiophen-2-yl)benzothiadiazole (TMS-T-BTD). The phase transition parameters and thermal stability of T-BTD and TMS-T-BTD were investigated using DSC and TGA methods. The presence of the trimethylsilyl end-groups in TMS-T-BTD significantly enhances solubility, increases the melting temperature, and improves the resistance of TMS-T-BTD to evaporation in the liquid state. Single crystals of T-BTD and TMS-T-BTD were grown from solutions, with the largest sizes being 7 × 2 × 0.5 mm3 and 8 × 1 × 0.45 mm3, respectively. Using single-crystal X-ray diffraction at 293 K, the crystal structure of T-BTD was refined in the rhombic system (sp.gr. Pcab, Z = 8), while for TMS-T-BTD, it was determined for the first time in the monoclinic system (sp.gr. P21/c, Z = 4). The relationship between observed growth anisotropy and molecular packing in the crystals was analyzed. The results of investigations into the spectral-fluorescent properties of solutions in hexane and THF are presented. The solvatochromic effect was studied in a series of solvents, including hexane, THF, dichloromethane, and acetonitrile. The photostability of the compounds in hexane solutions was examined. It was found that the quantum yield of photodestruction for T-BTD is 13 times higher than that of TMS-T-BTD. The fluorescent properties of T-BTD and TMS-T-BTD crystals were investigated.
