heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are important catalysts for several homogeneous and heterogeneous catalytic reaction. owing to the unique properties and the versatility of the heteropoly compounds as catalysts, achieve mild, fast, efficient and green procedures for the synthesis of fine chemicals.
in this study, some heteropoly catalysts with different counter cation or addenda atoms and supported hpas have been synthesized and characterized by, ftir, bet and tga/dsc. then, their catalytic activites have been investigated in synthesis of bis(indolyl)alkanes. besides, their catalytic activities have been discussed in relation to the catalyst acidity and textural properties.