Synthesis, crystal structure and physico-chemical properties of 3,3'-[(4-hydroxyphenyl)methyl] bis-(4-hydroxy-2H-chromen-2-one)

The compound 3,3'-[(4-Hydroxyphenyl)methyl]bis-(4-hydroxy-2H-chromen-2-one) was synthesized by the Knoevenagel reaction. Crystals, suitable for X-ray data collection, were grown by slow evaporation from an ethanol solution. The product 3,3'-[(4-Hydroxyphenyl)methyl]bis-(4-hydroxy-2H-chromen-2-one) · ethanol crystallizes in the monoclinic system, space group P2(1)/n. The ultraviolet/visible absorption spectra in different solvents were recorded. Sensitivity of the compound to solvent polarity and hydrogen bonding with protic (ethanol, H(2)O) and aprotic (dimethylsulfoxide, acetonitrile) solvents was detected. Based on (1)H-NMR spectroscopy as well as on potentiometric and UV/vis titration experiments the acid dissociation constants for 3,3'-[(4-Hydroxyphenyl)methyl]bis-(4-hydroxy-2H-chromen-2-one) were estimated.