In 2019,Chemical Science included an article by Zhou, Jiawang; Wu, Yilei; Roy, Indranil; Samanta, Avik; Stoddart, J. Fraser; Young, Ryan M.; Wasielewski, Michael R.. Formula: C8H8Br2. The article was titled 《Choosing sides: unusual ultrafast charge transfer pathways in an asymmetric electron-accepting cyclophane that binds an electron donor》. The information in the text is summarized as follows:
Constructing functional mol. systems for solar energy conversion and quantum information science requires a fundamental understanding of electron transfer in donor-bridge-acceptor (D-B-A) systems as well as competitive reaction pathways in acceptor-donor-acceptor (A-D-A) and acceptor-donor-acceptor’ (A-D-A’) systems. Herein we present a supramol. complex comprising a tetracationic cyclophane having both phenyl-extended viologen (ExV2+) and dipyridylthiazolothiazole (TTz2+) electron acceptors doubly-linked by means of two p-xylylene linkers (TTzExVBox4+), which readily incorporates a perylene (Per) guest in its cavity (Per ⊂ TTzExVBox4+) to establish an A-D-A’ system, in which the ExV2+ and TTz2+ units serve as competing electron acceptors with different reduction potentials. Photoexcitation of the Per guest yields both TTz+·- Per+·- ExV2+ and TTz2+-Per+·-ExV+·in < 1 ps, while back electron transfer in TTz2+-Per+·-ExV+· proceeds via the unusual sequence TTz2+-Per+· -ExV+· →TTz+· -Per+· -ExV2+ → TTz2+-Per-ExV2+. In addition, selective chem. reduction of TTz2+ gives Per ⊂ TTzExVBox3+· turning the complex into a D-B-A system in which photoexcitation of TTz+· results in the reaction sequence 2*TTz+· -Per-ExV2+ → TTz2+-Per-ExV+ → TTz +· -Per-ExV2+. Both reactions TTz2+-Per+· -ExV+· → TTz+ -Per+· -ExV2+ and TTz2+-Per-ExV+· → TTz+· -Per-ExV2+ occur with a (16 ± 1 ps)-1 rate constant irresp. of whether the bridge mol. is Per+ or Per. These results are explained using the superexchange mechanism in which the ionic states of the perylene guest serve as virtual states in each case and demonstrate a novel supramol. platform for studying the effects of bridge energetics within D-B-A systems.1,4-Bis(bromomethyl)benzene(cas: 623-24-5Formula: C8H8Br2) was used in this study.
1,4-Bis(bromomethyl)benzene(cas: 623-24-5) belongs to organobromine compounds.Depending on the type of carbon to which the bromine is bonded, organic bromide could be alkyl, alkenyl, alkynyl, or aryl. Formula: C8H8Br2 Due to the reactivity of bromide, they are used as potential precursors or important intermediates in organic synthesis.
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary