Proton and boron-11 magnetic resonance studies of some potassium tetraarylborates

✍ Scribed by John T. Vandeberg; Carl E. Moore; Frank P. Cassaretto

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 306 KB
• Volume: 5
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270050202

✦ Synopsis

Proton and boron-1 1 magnetic resonance spectra for several potassium para-substituted tetraarylborate compounds [KB(C6Ha-pX)4, where X is H, OCH,, CHa, Br, C1, F, CF,] have been obtained. The chemical shift between the centers of the AA' and XX' multiplets for the ring proton multiplets, relative to a reference chemical shift of 0.39 ppm for potassium tetraphenylborate, correlated with the corresponding Hammett G values for the para-substituent. Additionally, the boron-11 chemical shifts gave a good correlation with corresponding u values for the substituents.

Electronegativities ofpara-substituted phenyl rings were calculated and found to be approximately 2.70 for all compounds studied. It was shown that electronic substituent effects do not greatly influence the electron density surrounding the central boron atom in the tetraarylborate ions.