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Hydrothermal reactions of lanthanide metal salts with 2-sulfoterephthalate (2-stp) and 4,4′-bipyridine (4,4′-bipy) led to three coordination polymers, {[Ln(2-stp)(4,4′-bipy)(H 2 O)]·(H 2 O)}, [Ln = Gd ( 1 ), Ho ( 2 ) and Sm ( 3 )]. Their structures have been established by X-ray single crystal diffraction. Complexes 1 – 3 are isostructural with 2D framework in which all Ln III atoms are nine-coordinated. All these 2D layers are further interlinked via hydrogen bonds resulting in 3D architecture. The solid-state photoluminescence measurements display the characteristic luminescence of Ho ( 2 ) and Sm ( 3 ), which is due to efficient energy transfer from the ligands to the central Ln III ions via an “antenna effect”. Variable-temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field for 1 – 3 is studied which reveal mainly the presence of antiferromagnetic interactions and the thermal depopulation of Stark sublevels together with crystal field affects. [ABSTRACT FROM AUTHOR]