Two novel coordination polymers [Mn3(EPDA)2(H2O)8·(ENA)·(ClO4)·0.5(HClO4)·(CH3OH)·2(H2O)]n (1) and[Zn(EPDA)(H2O)]n (2) (EPDA = 5‐ethylpyridine‐2, 3‐dicarboxylic acid, ENA = 5‐ethylnicotinate acid) were synthesized and characterized by IR and UV/Vis spectroscopy, elemental analysis, PXRD, TGA, photoluminescence, and single‐crystal X‐ray diffraction. Organic EPDA2– and ENA– anions, the decomposition products of ENA‐Pmmi by removing the –Pmmi group under in situ solvothermal conditions, were obtained by performing the reactions of ENA‐Pmmi with MnII or ZnII perchlorate. In complex 1, the MnII ions were bridged by μ4‐EPDA2– anions to give a 2D positively charged layer, and the free ENA– anion and solvent molecules are filled into the gap between the layers through hydrogen bonding interactions to form a sandwich structure. In compound 2, the μ3‐EPDA2– anions bridge divalent Zn2+ ions to form a 1D chain, and the ENA– anions are not involved in stacking interactions but left in the residual solution. In addition, the ENA‐Imoi instead of ENA‐Pmmi, was selected to further investigate this reaction (ENA‐Pmmi and ENA‐Imoi are imazethapyr homologues), and the same experimental results could be obtained.