Abstract
Infrared, electronic and nuclear magnetic resonance spectra of cobalt (III) thio-β-diketonates were studied in comparison with those of cobalt (III) β-diketonates. Quasiaromaticity was more strongly supported in thio-β-diketonates than in β-diketonates by mainly the following observations. In thio-β-diketonates, absorption bands of ν (C-O) and ν (C-C) wereobserved at lower wave number than in corresponding β-diketonates. Chemical shifts of the protons of methine and methyl groups were found in lower field in thio-β-diketonates than those of corresponding β-diketonates. In Co (III) thioacetylacetonate a singlet was observed as a signal of methyl groups in nonpolar solvents. In Co (III) thio-β-diketonates which contain phenyl group, deshielding effect and mesomeric effect of phenyl group were also discussed in nuclear magnetic resonance spectra.
