We report herein the synthesis and physicochemical characterization of eight new manganese oxalato compounds with 1,2-bis(4-pyridypethylene (bpe): {(Hbpe)(2)[Mn-2(mu-ox)(3)]center dot similar to 0.8(C2H5OH)center dot similar to 0.4(H2O)}(n) (1), {[Mn(mu-ox)(mu-bPe)]center dot xH(2)O](n) (2), [Mn-2(mu-ox)(2)(mu-bpe)(bpe)(2)](n) (3), [Mn(mu-ox)(mu-bpe](n)(4a and 4b), and {[Mn-4(mu-ox)(3)(mu-bpe)(4)(H2O)(4)]center dot(X)(2)center dot mY}(n) with X = NO3- (5a), Br- (5b), and CIO4- (5c) and Y = salvation molecules. The appropriate selection of the synthetic conditions allowed us to control the crystal structure and to design extended 2D and 3D frameworks. Compound 1 is obtained at acid pH values and its crystal structure consists of stacked [Mn-2(mu-ox)(3)](2-) layers with cationic Hbpe(+) molecules intercalated among them. Compound 2 was obtained at basic pH values with a manganese/bpe ratio of 1:1, and the resulting 3D structure consists of an interpenetrating framework in which metal-oxalato chains are bridged by bpe ligands, leading to a microporous network that hosts a variable number of water molecules (between 0 and 1) depending on the synthetic conditions. Compound 3, synthesized with a manganese/bpe ratio of 1:3, shows a 2D framework in which linear metal-oxalato chains are joined by bis-monodentate 1,2-bis(4-pyridyl)ethylene ligands. The thermal treatment of compound 3 permits the release of one of the bpe molecules, giving rise to two new 2D crystalline phases of formula [Mn(mu-ox)(mu-bpe)](n) (4a and 4b) depending on the heating rate. The open structures of 5a-5c were synthesized in a medium with a high concentration of nitrate, perchlorate, or bromide salts (potassium or sodium as cations). These anions behave as templating agents directing the crystal growing toward a cationic porous network, in which the anions placed in the voids and channels of the structure present high mobility, as inferred from the ionic exchange experiments. Variable-temperature magnetic susceptibility measurements show an overall antiferromagnetic behavior for all compounds, which are discussed in detail.