Novel inorganic-bioorganic hybrid of nano titania and pseudo-ionic liquid of -mannitol/vitamin C (nano TiO2@D-M/VC) to promote water-mediated synthesis of dihydroxy-indeno-indolediones

In the present study, a novel titania-based inorganic-bioorganic nanohybrid has been prepared. For this purpose, a pseudo-ionic liquid (pseudo-IL) is obtained from the reaction of d -mannitol and ascorbic acid (vitamin C) ( D -M/VC), which is embedded on the nano TiO 2 core to obtain the nano inorganic-bioorganic hybrid (nano TiO 2 @ D -M/VC). TiO 2 @ D- M/VC nanostructure has been identified and characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDAX), and thermal gravimetric analysis/differential thermogravimetric (TGA/DTG) methods. Its catalytic efficacy has been investigated for the synthesis of dihydroxy-indeno[1,2- b ]indolediones through domino one-pot reaction of ninhydrin/acenaphthenequinone, dimedone/1,3-cyclohexanedione, and different anilines at ambient temperature in water media. The recovery and reusability of the nanostructure were also examined within 2 cycles and the recovered nanocatalyst investigated through FESEM method. • Preparation of a novel a pseudo-ionic liquid from the reaction of d -mannitol and ascorbic acid (vitamin C) ( D -M/VC). • Simple synthesis of a nano inorganic-bioorganic hybrid via embedding of D -M/VC of nano TiO 2 (nano TiO 2 @ D -M/VC). • Characterization of TiO 2 @ D- M/VC nanostructure by FTIR, FESEM, XRD, EDAX, and TGA/DTG methods. • Investigation the catalytic efficacy of nano TiO 2 @ D- M/VC for the synthesis of dihydroxy-indeno[1,2- b ]indolediones through domino one-pot reaction of ninhydrin/acenaphthenequinone, dimedone/1,3-cyclohexanedione, and different anilines at ambient temperature in water media. • Examining the recovery and reusability of the nanostructure within 2 cycles and characterization of the recovered nanocatalyst through FESEM method.