Synthesis, Photophysical, and (Spectro)Electrochemical Properties of New Benzo[1,2-][1,2,5]thiadiazoles and Benzo[1,2-][1,2,3]triazoles Fused with Two Thiazole Rings.

Acylation of benzo[][1,2,5]thiadiazole-4,7-diamine and 2-hexyl-2-benzo[][1,2,3]triazole-4,7-diamine with aromatic acid halides furnished the corresponding ,'-diamides, which were converted into ,'-dithioamides by reacting with Lawesson's reagent. A method was developed for the preparation of previously unknown fused systems, dithiazolobenzo[1,2-][1,2,5]thiadiazoles and dithiazolobenzo[1,2-][1,2,3]triazoles, by oxidative photochemical cyclization of ,'-dithioamides. The photophysical and (spectro)electrochemical properties of the obtained compounds and their polymer films electrochemically deposited on ITO were studied.

Photochemical Synthesis and Electrochemical and Photophysical Properties of 2,7-Diarylbenzo[1,2-d:4,3-d']bis(thiazoles).

This article focuses on the development of practical approaches to the preparation of benzo[1,2-:4,3-']bis(thiazoles) using blue light-induced photochemical cyclization of '-(1,4-aryl)dithioamides in the presence of -chloranil as a mild oxidant. The proposed method allows to obtain benzo[1,2-:4,3-']bis(thiazoles) containing donor substituents in the conjugated chain. Photophysical and (spectro)electrochemical properties of 2,6-di([2,2'-bithiophen]-5-yl)benzo[1,2-:4,3-]bis(thiazole) and -benzo[1,2-:4,5-']bis(thiazole) are studied in detail.

Rearrangement of 7-Aryloxazolo[5,4-]pyridines to Benzo[][1,7]naphthyridine-4(3)-ones and Thieno[3,2-][1,7]naphthyridine-6(7)-ones.

In this work, we describe the development of the rearrangement for 7-aryl-substituted oxazolo[5,4-]pyridines treated with aluminum chloride into synthetically hard-to-reach benzo[][1,7]naphthyridinones. The discovered rearrangement is applied to a variety of electron-rich (hetero)arene substrates. It offers the advantages of mild conditions (90 °C temperature), fast reaction rates (<4 h), compatibility with air moisture, and the use of inexpensive commercial reagents.

Synthesis of Bis([2,2'-bithiophen]-5-yl)-Substituted Oligothiadiazoles: Effect of the Number of Acceptor Units on Electrochemical and Spectroscopic Properties.

1,3,4-Thiadiazole, 2,2'-bi(1,3,4-thiadiazole), 2,2':5',2″-ter(1,3,4-thiadiazole), and 2,2':5',2″:5″,2‴-quater(1,3,4-thiadiazole) symmetrically disubstituted with 3-alkyl-(2,2'-bithiophen)-5-yl were synthesized by new procedures using readily available ethyl 3-alkyl-(2,2'-bithiophene)-5-carboxylate as a convenient substrate. These new compounds with a fixed number of donor rings and increasing number of acceptor rings showed very interesting, tunable redox properties. In particular, they exhibited electron affinities (EAs) ranging from -3.