Novel gallium and indium salts of the 12-tungstophosphoric acid: Synthesis, characterization and catalytic properties

The objective of this study was the preparation, characterization and testing of the catalytic properties of the GaPW12O40 and InPW12O40 salts of 12-tungstophosphoric heteropolyacid (HPW). The samples were characterized by XRD, IR, SEM, and P-31 and H-1 MAS NMR spectroscopy. The acid properties of the solids were directly accounted for by applying H-1 MAS NMR. The salts were screened in the etherification of 1-phenylethanol with C-1-C-4 alkanols in dichloromethane as a solvent to yield the corresponding C6H5-CH(OR)-CH3 unsymmetrical ethers. In comparison with pure HPW, the new salts revealed generally a higher selectivity of ethers formation at 65 degrees C. (c) 2012 Elsevier B.V. All rights reserved.