Push–pull chromophores by reaction of 2,3,5,6-tetrahalo-1,4-benzoquinones with 4-(N,N-dialkylanilino)acetylenes

A series of new push-pull chromophores were synthesized from electron-rich 4-(N,N-dialkylanilino) acetylenes and 2,3,5,6-tetrahalo-1,4-benzoquinones. The reactivity of the latter differs substantially from that of the previously investigated 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The transformation with fluoranil gave orange-colored, bis-donor-substituted chromophores with a tricyclic, cyclobutene-fused dihydrobenzofuranone core. In contrast, the reaction with chioranil yielded mono donor-substituted, blue 1,4-benzoquinone-based chromophores, which were further reacted with tertiary amines to form bis-donor-substituted push-pull systems. The structures of the new chromophores were confirmed by X-ray analysis, and mechanisms for their formation are proposed. They feature intense intramolecular charge-transfer bands in the visible region, and their optoelectronic properties were investigated by UV/Vis spectroscopy, electrochemistry, and computational analysis

Code of practice for electrical energy storage systems

The purpose of this Code of Practice is to provide a reference to practitioners on the safe, effective and competent application of electrical energy storage systems. It also provides an understanding of the common terms and operating modes of electrical energy storage systems. Building on the IET’s technical briefing: Electrical Energy Storage: an Introduction this will also provide detailed information on the specification, design, installation, commissioning, operation and maintenance of an energy storage system. The scope covers all types of electrical and electrochemical energy storage systems; integration into low voltage power systems; industrial, commercial and domestic applications and systems aligned with existing standards, regulations and guidance