# Strange 1H-NMR signals/signal ratio

Fedorov et al. assign the $^1$H-NMR ($\ce{CDCl3}$) chemical shifts of the $\ce{CH2}$ group in 2-(bromomethyl)phenylboronic acid

to three singlets at $4.75$, $5.09$ and $5.15~\ce{ppm}$ in a ratio of $3:3:14$.

Can someone explain their reasoning?

• Could you post the entire 1H-NMR analysis? The article is behind a paywall for me, and perhaps there is something in the rest of the data that is helpful. Jul 9 '15 at 0:06
• Regarding long's answer - do you still want this information? Jul 9 '15 at 0:27
• Nope. I was going to try to partially blame the potential NMR-activity of $\ce{^{11}B}$, which is a spin $\frac{3}{2}$, but I forgot about the tendency of boronic acids to oligomerize. Jul 9 '15 at 1:12