Gas-Phase Structure of N,N-Dimethylglycine

✍ Scribed by Alberto Lesarri; Emilio J. Cocinero; Juan C. López; José L. Alonso

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 173 KB
• Volume: 6
• Category: Article
• ISSN: 1439-4235
• DOI: 10.1002/cphc.200500103

✦ Synopsis

Abstract

Three conformers of the neutral amino acid N,N__‐dimethylglycine [(CH~3~)~2~NCH~2~COOH] were detected in a supersonic expansion by a combination of laser ablation (LA) and molecular‐beam Fourier transform microwave (MB‐FTMW) spectroscopy. A bifurcated methyl‐to‐carbonyl (CH⋅⋅⋅OC) weak intramolecular hydrogen bond might stabilise the most stable conformer of__ C~s~ symmetry. The second most stable conformer of C~1~ symmetry has a hydrogen bond between the hydroxyl group and the lone pair at the nitrogen atom (N⋅⋅⋅HO). The r~s~ and r~0~ structures were derived for this conformer from the rotational data for the parent and six minor ^13^C, ^15^N and OD isotopomers. A third conformer exhibits a cis__‐carboxyl functional group and__ C~1~ symmetry. Ab initio MP2/6‐311++G(d,p) predictions of the spectroscopic parameters were useful in analysing the spectra. In particular, the agreement of the nuclear quadrupole coupling constants with those calculated was conclusive in identifying the different conformers.