Entry of chiral phthalimides with significant second order nonlinear optical and piezoelectric properties

Three new chiral phthalimides have been synthesized and characterized. Phthalimides (1-3) possess an acentric structure as revealed by structural investigation. Compounds 1 and 2 crystallize in an orthorhombic system with the space group P2 sub(1)2 sub(1)2 sub(1), however the monoclinic system with the chiral space group P2 sub(1) is observed for 3. The presence of C-H...O hydrogen bonds in 1-3 facilitates the construction of several supramolecular structures. Helical structural motifs are also observed. The maximum value of hyperpolarizability ( beta ), 159.9446 10 super(-30) esu calculated for compound 3 is several times greater than that of urea. On the other hand 1 and 2 have hyperpolarizabilities of 10.8063 10 super(-30) and 121.9519 10 super(-30) esu, respectively. The polycrystalline samples of 1-3 were assessed for a second-harmonic generation response, which was found to be 8.8, 10.2 and 9.7 mV respectively. Further, compounds 1-3 showed d sub(33) values of 0.93, 1.97 and 1.88 pC N super(-1) respectively. The present investigation demonstrates chiral phthalimides as effective contenders for nonlinear optical and piezoelectric properties.