Synthesis, characterization and application of α-Ca3 (PO4)2 as a heterogeneous catalyst for the synthesis of 2.3-diphenylquinoxaline derivatives and knoevenagel condensation under green conditions

Highly economic and waste valorization strategy for multicomponent and Knoevenagel reactions using water extract of tamarind seed ash

The application of solid organic waste-originated products in the preparation of synthetically and biologically significant compounds in aqueous media or pure water is a highly desired task in chemical synthesis that shows an effective solution to the circular economy and sustainable environment. In this article, we describe our research on the development of highly economic and sustainable protocols for the synthesis of biologically important oxygen-heterocycles (using a multicomponent reaction) and synthetically important olefins (via the Knoevenagel condensation reaction) using water extract of tamarind seed ash (WETS) as catalyst and aqueous reaction medium. The reactions are carried out at room temperature (RT) under toxic/problematic/volatile organic solvent-free conditions. Products of the current methods have been purified by using recrystallization technique. WETS was characterized from its FTIR, powder XRD, SEM, and EDAX data. Problematic and non-renewable solvents were avoided throughout the process from their synthesis to purification. The utilization of solid organic waste-originated catalyst and aqueous media, avoid of non-renewable substances as catalysts, media, separation solvents and promoters, and unobligating heating conditions can surely attract the attention of chemists towards exploring the waste-based products in chemical transformations.

Crystal structure of barium dinickel(II) iron(III) tris-[orthophosphate(V)], BaNi2Fe(PO4)3

The orthophosphate BaNi₂Fe(PO₄)₃ has been synthesized by a solid-state reaction route and characterized by single-crystal X-ray diffraction and energy-dispersive X-ray spectroscopy. The crystal structure comprises (100) sheets made up of [Ni₂O₁₀] dimers that are linked to two PO₄ tetra-hedra via common edges and vertices and of linear infinite [010] chains of corner-sharing [FeO₆] octa-hedra and [PO₄] tetra-hedra. The linkage of the sheets and chains into a framework is accomplished through common vertices of PO₄ tetra-hedra and [FeO₆] octa-hedra. The framework is perforated by channels in which positionally disordered Ba²⁺ cations are located.