A novel, green and reusable nano ionic liquid and catalyst, namely 1-methylimidazolium trinitromethanide {[HMIM]C(NO2)3}, was designed and fully characterized by 1H NMR, 13C NMR, IR, mass, X-ray diffraction patterns (XRD) and Transmission electron microscopy (TEM) analysis. The catalytic application of the presented catalyst was successfully tested on the Hantzsch four-component reaction of various aromatic aldehydes, 1,3-dione, b-ketoester and ammonium acetate at room temperature under solventfree and mild conditions to give the polyhydroquinoline derivatives in good to excellent yields. In the presented work, some products have been reported for the first time.
