One-Dimensional Mixed-valence Ce(III)/Ce(IV)-Containing Arsenotungstate for Photocatalytic Synthesis of Quinazolines

Abstract

A novel mixed-valence cerium-containing polyoxometalate, Na18[Ce(III)2(H2O)12Ce(IV)6(μ3-O)4(μ3-OH)4(AsW9O33)4]·33H2O (Ce8As4W36), was synthesized and characterized. Ce8As4W36 is composed of a hexanuclear {Ce(IV)6O8} cluster surrounded by four trivacant Keggin-type [AsW9O33]9- units. These tetramers are further linked by additional Ce(III) ions to form a one-dimensional chain-like structure, exhibiting hierarchical assembly from discrete clusters to an extended structure. Moreover, Ce8As4W36 exhibits remarkable photocatalytic activity for the synthesis of quinazoline derivatives via the cyclization-oxidative aromatization of 2-aminobenzylamines with aldehydes.