Two new complexes [Mn(bpym)2(H2O)2][ClO4]2 (bd1) and [Mn(bpym)(NO3)2] (2) (bpym = 2,2′-bipyrimidine) have been prepared and characterized by spectroscopic and X-ray diffraction methods. Compound 1 consists of a mononuclear [Mn(bpym)2(H2O)2]2+ unit in which the manganese atoms shows a distorted elongated octahedral coordination with two bpym nitrogens and two H2O oxygens forming a cis configuration. The structure of compound 2 is made up of an infinite zigzag bpym-bridged polymeric chain with [Mn(bpym)(NO3)2] units, in which the manganese atom has seven coordination with four nitrogen atoms of two bpym ligands and three oxygen atoms of monodentate NO3− and bidentate NO3− anions. The intermetallic distance of Mn…Mn is 6.234(2) Å. The temperature dependence of the magnetic susceptibility of 2 reveals the presence of a one-dimensional Heisenberg antiferromagnetic chain with J = −0.93 cmsu−1.