Two new heterometallic coordination polymers [HoAg(Hbidc)(2)(H2O)(2)](n)center dot(H2O)(n) (1) and [EuAg (Hbidc)(2)(H2O)(4)](n)center dot(H2O)(n) (2) (H(3)bidc = 1H-benzimidazole-5,6-dicarboxylic acid) have been synthesized at hydrothermal conditions and characterized by elemental analysis, FT-IR, TG analysis, single-crystal X-ray diffraction and powder X-ray diffraction. Single-crystal X-ray structural analysis revealed that complex 1 possesses a 3D framework with a (3,7)-connected {3.4.5}{3(2).4(3).5(6).6(6).7(3).8} topological network. Complex 2 displays a 2D network with 3-connected {4.8(2)} topology. The luminescent properties of 2 were investigated in detail and its possible use as a conversion phosphor in white light-emitting diodes was evaluated. The complex shows bright red Eu3+ emission upon excitation at 400 nm due to a low-lying charge transfer state. The thermal quenching is already significant at room temperature.