Here, we report a new photosensitive metal–organic framework (MOF) that was constructed via the modification of UiO-66-NH2 with diarylethene molecules (DAE, 4-(5-Methoxy-1,2-dimethyl-1H-indol-3-yl)-3-(2,5-dimethylthiophen-3-yl)-4-furan-2,5-dione). The material that was obtained was a highly crystalline porous compound. The photoresponse of the modified MOF was observed via UV–Vis and IR spectroscopy. Most of the DAE molecules inside of the UiO-66-pores had an open conformation after synthesis. However, the equilibrium was able to be shifted further toward an open conformation using visible light irradiation with a wavelength of 520 nm. Conversely, UV-light with a wavelength of 450 nm initiated the transformation of the photoresponsive moieties inside of the pores to a closed modification. We have shown that this transformation could be used to stimulate hydrogen adsorption–desorption processes. Specifically, visible light irradiation increased the H2 capacity of modified MOF, while UV-light decreased it. A similar hybrid material with DAE moieties in the UiO-66 scaffold was applied for hydrogen storage for the first time. Additionally, the obtained results are promising for smart H2 storage that is able to be managed via light stimuli.

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Аннотация. Разработан пятистадийный метод синтеза новых дигетарилэтенов с 1,3-тиазольным мостиком, содержащих 2,5-диметилтиофеновый и замещенные 2H-хромен-2-оновые заместители. Вза-имодействием 5(3)-метоксизамещенных салициловых альдегидов с янтарным ангидридом в присут-ствии триэтиламина получают 6-метоксикумарин-и 8-метоксикумаринуксусные кислоты. Их обработ-ка тионилхлоридом приводит к соответствующим хлорангидридам, которые использовали для дальней-ших превращений без дополнительной очистки. Ацилирование 2,5-диметилтиофена хлорангидридами кумаринуксусных кислот по реакции Фриделя -Крафтса в присутствии хлорида алюминия приводит к 3-(2-(2,5-диметилтиофен-3-ил)-2-оксоэтил)-6-метокси-и -8-метокси-2H-хромен-2-онам, которые при действии сульфурилхлорида образуют соответствующие хлоркетоны. Строение всех промежуточных продуктов подтверждено методами ИК-Фурье, яМР 1 H спектроскопии, масс-спектрометрии и элемент-ного анализа. Полученые хлоркетоны легко циклизуются при помощи арилтиомочевин или тиоамидов различных кислот, что открывает перспективы синтеза широких серий новых фотохромных диарилэте-нов с замещенным кумариновым фрагментом.Ключевые слова: синтез, дигетарилэтены, 2H-хромен-2-он, 2,5-диметилтиофен, молекулярные переключатели. Abstract. Five-step method for the synthesis of novel dihetarylethenes with a 1,3-thiazole bridge containing 2,5-dimethylthiophene and substituted 2H-chromene-2-one substituents was developed. 6-Methoxycoumarinand 8-methoxycumarin acetic acids were prepared by interaction of 5(3)-methoxysubstituted salicylic aldehydes with succinic anhydride in the presence of triethylamine. Their treatment with thionyl chloride leads to the corresponding chloroanhydrides, which were used for further conversions without additional purification. Acylation of 2,5-dimethylthiophene with coumarinacetic acid chloroanhydrides via the FriedelCrafts reaction in the presence of aluminum chloride leads to 3-(2-(2,5-dimethylthiophen-3-yl)-2-oxoethyl)-6-methoxy-and -8-methoxy-2H-chromen-2-ones, which form the corresponding chloro ketones upon the action of sulfuryl chloride. The structure of all intermediate products was confirmed by FT-IR, 1 H NMR spectroscopy, mass spectrometry and elemental analysis. The obtained chloro ketones are easily cyclized by arylthioureas or thioamides of various acids, which gives the possibility for the synthesis of wide series of novel photochromic diarylethenes with substituted coumarin fragment. SYNTHESIS OF NOVEL NONSYMMETRIC

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