Synthesis, Structure, White-Light Emission, and Temperature Recognition Properties of Eu/Tb Mixed Coordination Polymers

Two series of EuIII/TbIII coordination polymers, [LnL­(glu)]n·2nH2O (Ln = Eu (1), Tb (2)) and [LnL­(glu)­(H2O)]n (Ln = Eu (3), Tb (4)) [HL = (2-(2-sulfophenyl)­imidazo­(4,5-f)­(1,10)-phenanthroline, H2glu = glutaric acid] have been hydrothermally synthesized by controlling the pH values and characterized by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. Isomorphic compounds 1 and 2 exhibit 6-connected 3D network with the pcu topological net, containing left- and right-handed helical chains. Isomorphic compounds 3 and 4 show 3,4-connected 2D new topology with the point symbol of (42·63·8)­(42·6). Multicolor luminescence can be tailored from red to green regions by singly varying the mixing molar ratio of EuIII/TbIII cations. The mixing component of 1Eu/2Tb = 4:6 not only achieves white-light emission with the CIE coordinate of (0.323, 0.339) upon excitation at 405 nm but also presents a temperature recognition property with the significantly high sensitivity of 0.68% per K in the 50–225 K temperature range upon excitation at 370 nm.