Wang, Sunewang R, Arrowsmith, Merle, Böhnke, Julian, Braunschweig, Holger, Dellermann, Theresa, Dewhurst, Rian, Kelch, Hauke, Krummenacher, Ivo, Mattock, James D, Müssig, Jonas, Thiess, Thorsten, Vargas, Alfredo and Zhang, Jiji (2017) Engineering a small HOMO-LUMO gap and intramolecular C-H borylation by diborene/anthracene orbital intercalation. Angewandte Chemie International Edition, 56 (27). pp. 8009-8013. ISSN 1433-7851

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Abstract

The diborene 1 was synthesized by reduction of a mixture of 1,2-di-9-anthryl-1,2-dibromodiborane(4) (6) and trimethylphosphine with potassium graphite. The X-ray structure of 1 shows the two anthryl rings to be parallel and their π(C14) systems perpendicular to the diborene π(B=B) system. This twisted conformation allows for intercalation of the relatively high-lying π(B=B) orbital and the low-lying π* orbital of the anthryl moiety with no significant conjugation, resulting in a small HOMO-LUMO gap (HLG) and ultimately an anthryl C-H borylation. The HLG of 1 was estimated to be 1.57 eV from the onset of the long wavelength band in its UV-vis absorption spectrum (THF, λonset = 788 nm). The oxidation of 1 with elemental selenium afforded diboraselenirane 8 in quantitative yield. By oxidative abstraction of one phosphine ligand by another equivalent of elemental selenium, the B-B and C1-H bonds of 8 were cleaved to give the cyclic 1,9-diborylanthracene 9.

Item Type:	Article
Schools and Departments:	School of Life Sciences > Chemistry
Subjects:	Q Science > QD Chemistry
Depositing User:	Alfredo Vargas
Date Deposited:	05 Jun 2017 08:13
Last Modified:	06 Jun 2018 01:00
URI:	http://sro.sussex.ac.uk/id/eprint/68175

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