Electron density studies on hydrogen bonding in two chromone derivatives

Abstract

The experimental electron densities of two chromone derivatives have been determined from X-ray synchrotron diffraction data at low temperature (100 K). Topological analysis of the electron density has been used to analyze the formation of resonance-assisted hydrogen bonds (RAHBs). Geometrical and topological parameters confirm π-electron delocalization within the hydrogen-bonded ring. In addition, weak C—H...O interactions were identified in both structures. Hydrogen-bond energies allowed medium and weak hydrogen bonds to be distinguished.