Cyclopentathiadiazines, new heterocyclic materials from cyclic enaminonitriles

Abstract

Indene and cyclopentene enaminonitriles were reacted with SCl2, iBu3N and NCS to give the first cyclopenta[1,2,6]thiadiazines that showed unusual characteristics, one as a NIR dye and another as a liquid crystal.

Cyclopentathiadiazines, Cyclohepta‐ and Cyclopentadithiazoles: New Materials and a Rich Heterocyclic Chemistry of Cyclic Enaminonitriles

“…In addition, compound 6 exhibited a broad signal of low intensity in its EPR spectrum, both in a solution of benzene and in the solid state, which could not be resolved. [11] Under the same conditions, compound 4 did not exhibit any EPR signals. Structure 6 can be formulated as 6a, a cyclic sulfurdiimide containing an oxidized sulfur() atom (Scheme 3), and 6b an unusual o-quinodimethane thiadiazine with a reduced sulfur() atom.…”

“…[7] Thus, the reaction of 4 with two equivalents of morpholine in Cl 2 CH 2 at reflux for 20 h gave exclusively the crystalline orange-red solid 5 (80 %). Compound 5 was fully characterized by spectroscopy, microanalysis and single-crystal X-ray diffraction, [11] which showed that only the 3-chloro atom was selectively substituted. We had expected that substitution of a halogen atom by a nitrogen atom would give rise to some bathochromic displacement of the absorption bands in the visible spectrum, but the UV spectra of 4 (λ max = 453 nm, ε = 1809 mol -1 dm 3 cm -1 ) and 5 (λ max = 469 nm, ε = 3917 mol -1 dm 3 cm -1 ) in CH 2 Cl 2 exhibited similar bands, probably because steric barriers prevented conjugation (see the Supporting Information).…”

“…Differential scanning calorimetry (DSC) exhibited a mesophase between 111 and 70°C on cooling. [11] Therefore, compound 7 is a new example of a rare class of liquid-crystal pseudoazulene. [16] The structure of 7 was further confirmed by its chemistry.…”

“…We have reported a related procedure that is suitable for the one-pot preparation of the first cyclopenta [1,2,6]thiadiazines by the reaction of indene and cyclopentene enaminonitriles and sulfur dichloride (SCl 2 ). [11] Shortly afterwards we discovered that cyclic enaminonitriles are also a good source of several heterocyclic systems. In this paper we report the selective preparation of benzocyclopenta-and cyclopentathiadiazines, as well as a new isothiazolocyclopentadithiazole, a cycloheptadithiazole and some cyclopentadithiazoles from five-and seven-membered cyclic enaminonitriles.…”

4H-1,2,6-Thiadiazin-4-one-containing small molecule donors and additive effects on their performance in solution-processed organic solar cells

“…Furthermore, fused analogues were studied as examples of "extreme quinoids" that have ambiguous aromatic character, 33 while others displayed unusual liquid crystalline properties or behaved as near-infrared dyes. 34,35 Herein, we show that 4H-1,2,6-thiadiazinone-containing small molecule donors can be used in BHJ OPVs. Systematic variations in the structures of the materials and use of a processing additive during device fabrication led to power conversion efficiencies of 2.7%.…”