Combined experimental and computational study on Ag-NPs immobilized on rod-like hydroxyapatite for promoting Hantzsch reaction

In this project, a bio-based heterogeneous catalyst is synthesized via multi steps process. First, nano-rod hydroxyapatite modified by silica compound is prepared, functionalized with of some nitrogen sources linkages such as, 4-aminoacetanilide and consequent immobilization of Ag nanoparticles by Sorbus aucuparia extract. The as-prepared catalyst, Ag@n-HA@SiO2-TAA, was successfully characterized by using FTIR, XRD, BET, SEM/EDX, TGA, TEM, ICP-AES and elemental mapping analysis. Furthermore, metal-ligand interactions in Ag@n-HA@SiO2-TAA complex models were assessed to interpret the immobilization behavior of Ag-NPs on the surface of nano-rod hydroxyapatite through quantum chemistry computations. The catalytic activity of the Ag@n-HA@SiO2-TAA was investigated in multi-component Hantzcsh reactions under mild conditions to furnish the corresponding products in high yields and short reaction times. Moreover, the recyclability study and Ag leaching of the Ag@n-HA@SiO2-TAA verified that the catalyst could be easily recovered and also recycled up to six runs with only slight loss of activity.