The Crystal Structure and the Fluorescent Properties of Curcumin

Abstract

The molecular and crystal structure of curcumin was investigated by X-ray analysis at a room temperature of 23°C. Anhydrous crystal was obtained from methanol. The crystal is monoclinc, and the spacegroupis P2/n with Z=4.The cell dimensions are as follows, a = 12.688(3)A, b = 7.2061(5)A, c = 19.897(5)A, ii= 95.28°(1). In this structure, the molecules are aggregated intermolecularly into infinite chains linked between the phenyl OH and the carbonyl 0 (or-OH). The hydrogen bond between 01-04 was weaker than that found in the previous work due to a longer intermolecular distance. It could be suggested that the enol-ring was found to be more asymmetric than in the previous work. Such a network formation is attributed to intermolecular hydrogen bonds between terminal phenol moieties of curcumin assembling a fibrous structure. Futhermore, it was found that the hydrogen bonding played an important role in the molecular packing of crystal curcumin. Crystal curcumin interacted with solids and showed potential for use as an environmental probe for the estimation of solid surfaces on the basis of its fluorescent properties and interactions with polar materials.