Trimetallic ferrite functionalized by guaninium tartrate ionic liquid (Co0.2Zn0.6Cu0.2Fe2O4-SiO2@[GuaH]+[Tar]2‒[GuaH]+) as a novel inorganic-bioorganic nanostructure to promote aqua-mediated synthesis of polyhydroxy-substituted pyridine-dipyrimidine fused heterocycles.

In this work, a Cobalt-Zinc-Copper ferrite (Co0.2Zn0.6Cu0.2Fe2O4, CZCF) was synthesized and functionalized with silica and guaninium tartrate ionic liquid (Co0.2Zn0.6Cu0.2Fe2O4-SiO2@[GuaH]+[Tar]2‒[GuaH]+). The novel bio-nanostructure was characterized by various techniques such as fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray analysis (EDAX), EDAX mapping, field emission scanning electron microscopy (FESEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric/differential thermal gravimetric analysis (TGA/DTG), vibrating sample magnetometry (VSM), high resolution transmission electron microscopy (HRTEM), and zeta potential analysis. The synthesized bio-nanocomposite exhibited high catalytic activity for the aqua-mediated synthesis of polyhydroxy-substituted pyridine-dipyrimidine fused heterocycles through the one-pot pseudo four-component reaction of carbohydrates (sugars), barbituric acid, and amines under refluxing conditions. The recyclability and reusability of the bio-nanocatalyst were successfully investigated for up to three runs. Moreover, the features of the recovered Co0.2Zn0.6Cu0.2Fe2O4-SiO2@[GuaH]+[Tar]2‒[GuaH]+ were examined via the EDAX analysis and FESEM images. In the theoretical section, the interaction sites between L-tartaric acid and guanine in an aqueous medium were investigated at the B3LYP/6-311++G(d,p) computational level. Additionally, the formation of more stable configurations of dimers and trimers in IL was studied from a thermodynamic point of view.