In this present work, the synthesis of zinc oxide (ZnO) nanoparticles (NPs) carried out at room temperature via green method (plant mediated) using Coriandrum sativum leaf extract. The prepared nanoparticles were characterized by FTIR, UV-Visible, XRD and SEM techniques to confirm its formation. It is observed from the FTIR spectrum that Coriandrum sativum leaf extract is significantly rich in different chemical groups such as –OH, –COOH and amine. Absorption UV-spectra analysis of synthesized ZnONPs was performed to study the optical property, found to be the band width of 3.8 eV and to confirm the presence of zinc oxide nanoparticles. The absorption spectrum reveals strong absorption peak at 272 nm within the absorption range 200-650 nm, which confirms formation of ZnO nanoparticles. The XRD pattern shows sharp and narrow diffraction peaks suggest that synthesized product has the good crystallinity with relatively larger crystallites, and signifies the effects of experimental conditions on the nucleation and growth of the crystal. The XRD patterns shows the noticeable peaks corresponding to 2θ values of 31.64°, 34.43°, 36.28°, 47.75°, 56.52°, 63.45°, 67.91° and 69.25°. The calculated value of crystalline size was found to be 60 nm and closely matched with wurtzite structure of ZnO. The SEM images showed that the particles are well shaped and spherical in the size range 30-150 nm, and there is fairly large number of individual small nanoparticles along with very few agglomerated relatively bigger particles. Further, these nanoparticles were applied as green catalyst in the synthesis organic chemistry transformations. ZnONPs used as heterogeneous green catalyst in the preparation of chalcones (E)-N-phenyl-3-(substituted)-acrylamide 3(a-f) (chalcones) by the condensation of aromatic aldehydes and acetanilide is reported. This method includes, cost effective, high yields, easy workup procedure, short reaction time at room temperature are the main advantages of this procedure is described.

Keywords: Green Synthesis; Coriandrum sativum Leaves; Zinc Oxide Nanoparticles; Chalcones;