Highly Luminescent Solution-Grown Thiophene-Phenylene Co-Oligomer Single Crystals

Thiophene-phenylene co-oligomers (TPCOs) are among the most promising materials for organic light emitting devices. Here we report on record high among TPCO single crystals photoluminescence quantum yield reaching 60%. The solution-grown crystals are stronger luminescent than the vapor-grown ones, in contrast to a common believe that the vapor-processed organic electronic materials show the highest performance. We also demonstrate that the solution grown TPCO single crystals perform in organic field effect transistors as good as the vapor-grown ones. Altogether, the solution-grown TPCO crystals are demonstrated to hold great potential for organic electronics.</p

Use of occlusal digital splint for treating the patients with temporomandibular joint dysfunction and planning orthopedic treatment

Objective of the study: to develop and assess the occlusal digital splint for treating patients with temporomandibular joint dysfunction (TMJD). Material and Methods — 17 patients between the ages of 30 and 49 diagnosed with TMJD were admitted for treatment. To normalize mandibular position, an occlusal digital splint for all patients was manufactured in accordance with our original method. An intensity of pain sensations in all patients prior to, and after, the treatment was assessed by a visual analogue scale, along with the changes in the mandibular movements’ amplitude, and the signs of splint wear and stability of occlusal contacts. Results — Patients have adapted themselves well to the splint and found it convenient in use. The study results showed that it was sufficiently effective in treatment of TMJD. Reduction in pain intensity and restoration of mandibular movements’ amplitude were detected with certainty. Only in 2 (11.7%) cases, the signs of wear on the splint were found, as evidenced by the changes in pre-treatment occlusal contacts. In all other cases throughout the study, a stable occlusal contact has been encountered. Conclusion — Our results indicated that proposed occlusal digital splint may be considered as a treatment option for the patients with TMJ disorders

Preparation and Synthetic Applicability of Imidazole-Containing Cyclic Iodonium Salts

A novel approach to the preparation of imidazole-substituted cyclic iodonium salts has been developed via the oxidative cyclization of 1-phenyl-5-iodoimidazole using a cheap and available Oxone/H2SO4 oxidative system. The structure of the new polycyclic heteroarenes has been confirmed by single-crystal X-ray diffractometry, revealing the characteristic structure features for cyclic iodonium salts. The newly produced imidazole-flanked cyclic iodonium compounds were found to readily engage in a heterocyclization reaction with elemental sulfur, affording benzo[5,1-b]imidazothiazoles in good yields.The heterocyclization study was supported by the Russian Science Foundation (project No. 17-73-20066). Y.A.V. kindly acknowledges the financial support from the Russian Foundation of Basic Research for the development of oxidative cyclization process (project No. 20-33-90007). This work was funded by Spain’s MINECO (CTQ2017-86936-P), AGAUR (2017 SGR 01051), and additional support from CSIC. The authors would like to acknowledge the Multi-Access Chemical Research Center SB RAS (N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry) and the Center for Chemical Analysis and Materials Research of Saint Petersburg State University for analytical measurements. X-ray structural results were obtained using the material and technical base of the Baikal Analytical Center for Collective Use of the SB RAS.Peer reviewe

Molecularly Smooth Single-Crystalline Films of Thiophene–Phenylene Co-Oligomers Grown at the Gas–Liquid Interface

Single crystals of thiophene–phenelyne co-oligomers (TPCOs) have previously shown their potential for organic optoelectronics. Here we report on solution growth of large-area thin single-crystalline films of TPCOs at the gas–liquid interface by using solvent–antisolvent crystallization, isothermal slow solvent evaporation, and isochoric cooling. The studied co-oligomers contain identical conjugated core (5,5′-diphyenyl-2,2′-bithiophene) and different terminal substituents, fluorine, trimethylsilyl, or trifluoromethyl. The fabricated films are molecularly smooth over areas larger than 10 × 10 μm², which is of high importance for organic field-effect devices. The low-defect structure of the TPCO crystals is suggested from the monoexponential kinetics of the PL decay measured in a wide dynamic range (up to four decades) and from low crystal mosaicity assessed by microfocus X-ray diffraction. The TPCO crystal structure is solved using a combination of X-ray and electron diffraction. The terminal substituents affect the crystal structure of TPCOs, bringing about the formation of a noncentrosymmetric crystal lattice with a crystal symmetry <i>Cc</i> for the bulkiest trimethylsilyl terminal groups, which is unusual for linear conjugated oligomers. Comparing the different crystal growth techniques, it is concluded that the solvent–antisolvent crystallization is the most robust for fabrication of single-crystalline TPCOs films. The possible nucleation and crystallization mechanisms operating at the gas–solution interface are discussed