Two coordination polymers formulated as [{[Co-2(L)(N-3)(4)]center dot 2DMF}(n) (1) and [Mn-2(L)(H2O)(0.5)(N-3)(8)](n) (2) (L = 1,4-bis(4-carboxylatopyridinium-1-methyl)-benzene) were synthesized and structurally and magnetically characterized. In compound 1, the anionic uniform Co(II) chains with mixed (mu-EO-N-3)(2)(mu-COO) triple bridges (EO = end-on) are cross-linked by the cationic bis(pyridinium) spacers to generate 2D coordination layers. It was demonstrated that the triple bridges mediate ferromagnetic coupling and that the compound represents a new example of the rare systems exhibiting the coexistence of antiferromagnetic ordering, metamagnetism, and slow magnetic dynamics. Compound 2 features the magnetic Delta-chain formed from isosceles triangular units with single mu-EE-N-3 and double (mu-EO-N-3) (mu-COO) bridges (EE = end-to-end). The Delta-chains are interlinked by long organic ligands into a 3D framework with novel net topology and 3-fold interpenetration. The magnetic properties of 2 indicate the presence of spin frustration characteristic of Delta-chains with antiferromagnetic interactions.