Studies on bis(1’-ortho-carboranyl)benzenes and bis(1’-ortho-carboranyl)biphenyls

Harder, R.A.; MacBride, J.A.H.; Rivers, G.P.; Yufit, D.S.; Goeta, A.E.; Howard, J.A.K.; Wade, K.; Fox, M.A.

Abstract

Reactions between the C,C’-dicopper(I) derivative of ortho-carborane and ortho-, meta- and para-diiodobenzene are reported. The reaction with 1,2-C6H4I2 unexpectedly afforded 2,2’-bis(1’-ortho-carboranyl)biphenyl, [HCB10H10CC6H4]22, whereas reactions with 1,3- or 1,4-C6H4I2 provided alternative routes to 1,3-bis(1’-ortho-carboranyl)benzene 3 and 1,4-bis(1’-ortho-carboranyl)benzene 4 respectively. The crystal structure of the biphenyl derivative 2 revealed significant distortions in the biphenylene framework attributable to the proximity of the two bulky carborane cages. UV absorption spectra and electrochemical data on 2 and 3 showed little electronic communication between the two carborane cages in either, and negligible pi-conjugation between the two ortho-phenylene rings in 2. However, substantial evidence was found of electronic communication between the carborane cages via the para-phenylene bridge in 4. B3LYP/6-31G* computations have been carried out on compounds 2 and 4, on 4,4’-bis(ortho-carboranyl)biphenyl 6 and on 1,2-bis(1’-ortho-carboranyl)benzene 7. Those on 2, 4 and 6 show the computed geometries to be in very good agreement with the experimental geometries: those on 7 allowed the reported molecular geometry of this compound to be revised and revealed a long cage C-C bond of 1.725(3)A.

Citation

Harder, R., MacBride, J., Rivers, G., Yufit, D., Goeta, A., Howard, J., …Fox, M. (2014). Studies on bis(1’-ortho-carboranyl)benzenes and bis(1’-ortho-carboranyl)biphenyls. Tetrahedron, 70(34), 5182-5189. https://doi.org/10.1016/j.tet.2014.05.102

• Journal Article Type: Article
• Acceptance Date: May 27, 2014
• Publication Date: Aug 26, 2014
• Deposit Date: Jun 9, 2014
• Publicly Available Date: Jun 9, 2014
• Journal: Tetrahedron
• Print ISSN: 0040-4020
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 70
• Issue: 34
• Pages: 5182-5189
• DOI: https://doi.org/10.1016/j.tet.2014.05.102
• Public URL: https://durham-repository.worktribe.com/output/1450507