Tautomerism of azo dyes in the solid state studied by 15N, 14N, 13C and 1H NMR spectroscopy, X-ray diffraction and quantum-chemical calculations

摘要: Abstract The azo–hydrazo tautomerism of four model azo dyes in the solid state is investigated by multinuclear solid-state nuclear magnetic resonance (SS-NMR) spectroscopy, X-ray diffraction and quantum-chemical calculations. measurement 15N SS-NMR spectra most straightforward way to determine tautomeric compounds. Unfortunately, sensitivity these nuclei for very low acquisition a reasonable time may be challenging. It demonstrated that natural abundance almost 100% another nitrogen isotope, 14N, can exploited investigation tautomerism. Indirect detection 14N via protons an elegant approach rapid unequivocal determination form. Furthermore, comparison experimental carbon chemical shifts with those obtained solution or computations used same purpose.