Use of indirect 199Hg NMR detection for aromatic mercury compounds of biological interest

✍ Scribed by Vincent Neirinck; Danielle Robert; Robert Nardin

• Book ID: 102951497
• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 613 KB
• Volume: 31
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260310905

✦ Synopsis

Abstract

When vanillin (4‐hydroxy‐3‐methoxbenzaldehyde) and syringaldehyde (4‐hydroxy‐3,5‐dimethoxybenzaldehyde) react with Hg(OAc)~2~, selective monomercuration occurs on the aromatic ring. The three ^3^J, ^4^J and ^5^(^199^Hg,^1^H) coupling constants of phenylmercury acetate were used as 1/2__J__ delays in the 1D inverse ^1^H ^199^Hg, sequence applied to 5‐acetoxymercuriovanillin and 2‐acetoxymercuriosyringaldehyde, the edited proton spectra obtained for each ^n^J(^199^Hg, ^1^H) coupling gave the value of n and the J(^199^Hg, ^1^H) coupling constants, and therefore yielded information about the position of the mercury substitution on the aromatic ring. A 2D ^199^Hg,^1^H shift correlation with ^1^H detection was applied in the case of phenylmercury acetate, using the mean value of the three J couplings; the ^3^J and ^4^J couplings were clearly resolved. As vanillin and syringaldehyde are representative monomer models of lignin, the indirect detection of ^199^Hg is then an appropriate method to determine the aromatic substitution pattern, which is a key point in lignin structural elucidation.