The Polymorphs of Diacetylcurcumin (DAC)

Herein, Diacetylcurcumin (DAC), a derivative of curcumin, was synthesised, and two new polymorphs (monoclinic and triclinic) are reported in addition to the previously known polymorph (P2₁). Solid-state NMR (CP-MAS) and X-ray studies allowed the unambiguous authentication of the elusive polymorph 2 (canoe-shaped, P2₁/n) and the concomitant polymorph 3 (elliptical-shaped, P-1). We demonstrate that morphological crystal analysis under a microscope, in conjunction with ATR-IR, is a rapid and inexpensive technique for exploring the polymorphic landscape of curcuminoids. This discovery highlights the ongoing progress in curcumin derivative research and should inspire fellow chemists and materials scientists to further explore it.