Two new 3d-4f heterometallic coordination polymers [Mn(0.5)Ln(INAIP)(2)(H2O)(2)]center dot 2H(2)O [ Ln = Eu (1), Gd (2)] have been prepared by hydrothermal reactions of the corresponding lanthanide salt with 5-(isonicotinamido) isophthalic acid (H(2)INAIP) in the presence of MnCO3 and NaOH. Both complexes have been characterized by single crystal X-ray diffraction analyses, elemental analyses, infrared absorption spectra, and thermogravimetric analyses. The results of structural analyses show that 1 and 2 are isostructural and feature non-interpenetrated 3D coordination framework containing 2D...