Precursor method was used in order to obtain alkali earth metal indates. The multimetallic complexes, namely: (NH(4))(4)[CaIn(2)(C(4)O(6)H(4))(3)(OH)(6)]center dot 4H(2)O, (NH(4))(3)[SrIn(2)(C(4)O(6)H(4))(3)(OH)(5)]center dot 4H(2)O and (NH(4))(3)[BaIn(2)(C(4)O(6)H(4))(3)(OH)(5)]center dot 3H(2)O have been synthesized and investigated by infrared and emission spectra as well as by thermal analysis. The alkali earth metal indates obtained by decomposition of these compounds have been characterized by X-ray powder diffraction, infrared, diffuse reflectance and emission spectra. The photocatalytic activity was evaluated.