N-methylimidazolium containing metal phosphate-oxalates: solvent-free synthesis, crystal structure, and proton conduction

Two N-methylimidazolium containing metal phosphate-oxalates (denoted SCU-40 and SCU-42) were prepared under solvent-free conditions. SCU-40 has a three-dimensional structure with a zeolitic crb topology, while SCU-42 has a layered structure...

Synthesis, Magnetic Property and Assembly Studies of Two Cu(II) Complexes Based on o-phenanthroline and Phosphate

Using newly precipitated Cu(OH)2, o-phenanthroline and phosphoric acid as raw materials, two complicated Cu(II) compounds were obtained by one-pot method. They are double-nuclear Cu(II) 1, {[Cu2(phen)2(H2PO4)3][Cu2(phen)2(H2O)(H2PO4)3]}·2H2PO4·5H2O, and mononuclear Cu(II) 2, [Cu(phen)2(H2PO4)]4·4H3PO4·2HPO4·6H2O. The crystal structure analysis showed that the copper phosphate reacted with the neutral ligand o-phenanthroline to obtain the compounds with different structures. Phosphoric acid can exist in various forms in copper complexes, such as H3PO4, (H2PO4)1-, (HPO4)2-, and form a rich and colorful supramolecular interaction with water molecules. Hirschfeld surface analysis gives the types and regions of molecular interactions in crystals. It is of scientific significance to understand the reaction between transition metal phosphate and organic neutral ligand. The thermogravimetric and magnetic properties of compounds 1 and 2 were also reported. Magnetic analysis shows that supramolecular interactions and dipole-dipole interactions have great influence on the magnetic properties of two compounds. CCDC: 20565681 for 1; 2090334 for 2.

Vapour-Phase Selective O-Methylation of Catechol with Methanol over Metal Phosphate Catalysts

Guaiacol (2-methoxyphenol), an important fine chemical intermediate, is conventionally synthesized by liquid-phase processes with expensive, corrosive and toxic methylating agents such as dimethyl sulphate and dimethyl iodide. Recently, vapour-phase alkylation of catechol (1, 2-dihydroxybenzene) with methanol for the synthesis of guaiacol in the presence of heterogeneous catalysts has received more attention, as the route is economical and environmentally friendly. However, most of the investigated catalysts exhibited unsatisfactory catalytic performance for industrial applications. In this study, five metal phosphates M-P-O (M = La, Ce, Mg, Al, Zn) catalysts were synthesized and tested in the selective O-methylation of catechol with methanol. Among these catalysts, cerium phosphate (CP) showed the highest catalytic activity and guaiacol yield. Lanthanum phosphate (LP) was the second most active, which was still obviously better than magnesium phosphate (MP) and aluminium phosphate (ALP). Zinc phosphate (ZP) was not active in the reaction. Relevant samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), N2 adsorption-desorption, temperature programmed desorption of NH3 or CO2 (NH3-TPD, CO2-TPD). The suitable acid-base properties contribute to the superior catalytic performance of CP. Long-term stability and regeneration tests were also studied.