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A novel magnetic inorganic-organic nanohybrid material H6P2W18O62/pyridino-Fe3O4 (HPA/TPI-Fe3O4) was fabricated and performed as an efficient, eco-friendly, and highly recyclable catalyst for the solvent-free, one-pot, and multi-component synthesis of various substituted 1-amidoalkyl-2-naphthols from the reaction of β-naphthol, an aldehyde, and benzamide with good to excellent yields (47-94%) and in a short span of time (25-60 min). The nanohybrid catalyst was prepared by the chemical anchoring of Wells-Dawson heteropolyacid H6P2W18O62 onto the surface of modified Fe3O4 nanoparticles with N-[3-(triethoxysilyl)propyl]isonicotinamide (TPI) linker. The magnetically recoverable catalyst was easily recycled at least eight times without any loss of catalytic activity. XRD, TEM, UV-vis, and FTIR confirmed that the heteropolyacid H6P2W18O62 is well dispersed on the surface of the solid support and its structure is retained after immobilization on the pyridine modified Fe3O4 nanoparticles. This protocol is developed as a safe and convenient alternate method for the synthesis of 1-amidoalkyl-2-naphthols utilizing an eco-friendly, and a highly reusable catalyst.

A new inorganic-organic nanohybrid material H4SiW12O40/pyridino-MCM-41 was prepared and performed as an efficient, eco-friendly, and highly recyclable catalyst for the one-pot multi-component synthesis of different substituted 1-amidoalkyl-2-naphthols under solvent-free conditions. The nanohybrid catalyst was prepared through electrostatic anchoring of Keggin heteropolyacid H4SiW12O40 on the surface of MCM-41 nanoparticles modified by N-[3-(triethoxysilyl)propyl]isonicotinamide. The prepared material was characterized by XRD, SEM, EDX, UV-Vis, DTA-TGA, DLS, and FT-IR spectroscopy. Findings confirmed that the heteropolyacid is well dispersed on the surface of the solid support and its structure is preserved after immobilization on the TPI modified MCM-41 nanoparticles. The recovered catalyst was easily recycled for at least seven runs without considerable loss of catalytic activity.

A SBA-15/polyaniline para-toluenesulfonic acid nanocomposite supported micro-solid-phase extraction procedure has been developed for the extraction of parabens (methylparaben, ethylparaben, and propylparaben) from wastewater and cosmetic products. The variables of interest in the extraction process were pH of sample, sample and eluent volumes, sorbent amount, salting-out effect, extraction and desorption time, and stirring rate. A Plackett-Burman design was performed for the screening of variables in order to determine the significant variables affecting the extraction efficiency. Then, the significant factors were optimized by using a central composite design. The optimum experimental conditions found at 50 mL sample solution, extraction and desorption times of 40 and 20 min, respectively, 500 μL of 3% v/v acetic acid in methanol as eluent, 0.01 M salt addition, and 10 mg of the sorbent. Under the optimum conditions, the developed method provided detection limits in the range of 0.08-0.4 ng/mL with good repeatability (RSD% < 7) and linearity (r(2) = 0.997-0.999) for the three parabens. Finally, this fast and efficient method was employed for the determination of target analytes in cosmetic products and wastewater, and satisfactory results were obtained.

A new inorganic-organic hybrid material Al-SBA-15-TPI/H6P2W18O62 was prepared and fully characterized by SEM, XRD, FT-IR, TGA-DTA, and UV-Vis spectroscopic techniques. Then, the prepared nanomaterial was used as a simple, cost-effective, and reusable heterogeneous catalyst for the synthesis of 2H-indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives by a one-pot, three-component condensation reaction of phthalhydrazide, cyclic diones, and aromatic aldehydes under solvent free conditions at 100 °C in a short time. This methodology has proven to be efficient and environmentally benign in terms of high yields and low reaction times and offers significant improvements with regard to the scope of transformation and simplicity of operation by avoiding expensive or corrosive catalysts.