Refine
Has Fulltext
- yes (6)
Is part of the Bibliography
- yes (6)
Document Type
- Preprint (4)
- Journal article (2)
Language
- English (6) (remove)
Keywords
- boron (4)
- diborenes (4)
- 1,2-additions (1)
- N-heterocyclic carbenes (1)
- \(\pi\) interactions (1)
- boron chains (1)
- borylation (1)
- carbenes (1)
- cations (1)
- diboranes (1)
- diborynes (1)
- hydroarylation (1)
- hydroboration (1)
- iodine (1)
- low-valent main-group species (1)
- main group elements (1)
- main-group chemistry (1)
- multiple bonding (1)
- multiple bonds (1)
- photoisomerization (1)
- pi-conjugation (1)
- small HOMO-LUMO gap (1)
- solid-state NMR (1)
- triboranes (1)
Institute
Sonstige beteiligte Institutionen
EU-Project number / Contract (GA) number
- 669054 (6) (remove)
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(C\(_{14}\)) 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 unprecedented anthryl B–B bond hydroarylation. 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, λ\(_{onset}\) = 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 C\(^1\)–H bonds of 8 were cleaved to give the cyclic 1,9-diboraanthracene 9.