Two 3D isostructural metal-organic frameworks with 1D ferrimagnetic chains, formulated as [M-3(L)(mu(3)-OH)(2)(H2O)(4)] [H4L = (1,1':4',1 ''-terphenyl)-2',3,3 '',5'-tetracarboxylic acid, where M = Mn for 1 and Co for 2], have been successfully synthesized by employing different center metal ions and a multicarboxylate ligand under identical reaction conditions in this work. The single-crystal X-ray diffraction data of 1 and 2 reveal that the complexes are two 3D isostructural frameworks based on 1D [M-3(OH)(2)](n) chains composed of triangular subunits as rod-shaped secondary building units, which are classified as binodal 4,6-connected fry nets with the point symbol (5(10). 6(3).7(8))(5(4).6(2)). The magnetic properties revealed that complexes 1 and 2 exhibit ferrimagnetic behavior. Also, the alternating-current susceptibility of 2 displays slow magnetic relaxation, showing interesting magnetic behavior of a single-chain magnet with an effective energy barrier of 32 K.