Molecular complexes of iodine with pyrone-(4) and 1-thiopyrone-(4)

Abstract

Thermodynamic data for the formation of iodine complexes with pyrone-(4) (I) and 1-thiopyrone-4 (11) have been obtained from measurements of the blue-shifted iodine band. The thiocarbonyl analogs of I and I1 are found to undergo irreversible reactions with iodine. The values of AHo and A G O 2 9 8 indicate that I1 is only slightly more basic toward iodine than is I. From a comparison of thermodynamic data for iodine complexes of ethers, thioethers, and ketones with that reported here for I and I1 with iodine, it is evident that the bonding site in I and I1 is the carbonyl oxygen. The differences between I and I1 may be explained mainly in terms of the electron density at the carbonyl oxygen.

Effect of organic ligands with conjugated π‐bonds on the structure of iodine–α‐dextrin complexes

“…The theoretical heat of formation Δ H theor was calculated for the temperature 298.15 K. Theoretical ΔH theor calculated by the RHF/3‐21G ** method is close to the experimental values 15–19.…”