C-13 CPMAS NMR-SPECTRA OF SOLID PROTON-EXCHANGING P-SUBSTITUTED BENZOYLACTONES - OBSERVATION OF C-13, CL-35, CL-37 RESIDUAL DIPOLAR COUPLING IN THE P-CHLORO DERIVATIVE

Residual dipolar coupling to spin-1/2 Cl-35, Cl-37 nuclei appears as a symmetric doublet of 0.69 kHz in the C-13 CPMAS NMR spectrum of p-chlorobenzoylacetone at 75.4 MHz, in agreement with theoretical calculations; carbon chemical shifts of a series of p-substituted benzoylacetones undergoing solid proton transfer are also reported, which show tautomeric populations similar to the solution ones.