Intramolecular H-bonds in the crystal of tetraacetylethane: 3c-4e interaction or a dynamic disorder?

The analysis of the experimental electron density function and anisotropic displacement parameters in tetraacetylethane has revealed that the intramolecular O–H···O bond corresponds to the intermediate type of interatomic interactions and that the variation of the C–O and C–C bond lengths with temperature (110–298 K) is the result of the dynamic disorder (superposition of tautomers) due to interatomic C–H···O contacts.