Structures and/or magnetic properties of three 1D ladder-type manganic and cadmium compounds with open-chain diazine Schiff-base ligands

Three new coordination polymers [MnL1(dca)2]n (1) (L1 = 1-(2-pyridyl)-4-(2-pyrazinyl)-4-amino-1-methyl-2,3-diaza-1,3-butadiene, dca = N(CN)2-), [CdL2(dca)2]n (2) (L2 = 1-(2-pyridyl)- 4-(2-pyrazinyl)-4-amino-2,3-diaza-1,3-butadiene) and [CdL1(dca)2]n (3) have been synthesized, structurally and/or magnetically characterized. In these isostructural compounds, metal ions of octahedral geometry are bridged by double μ1,5-mode dca ions and further interlinked into a 1D ladder-type chain by two single μ1,5-mode dca ions with the Schiff-base ligands acting only as bidentate ligands. Variable temperature magnetic studies have shown that the coupling interaction between Mn(II) centers of the ladder-type Mn-dca chains is weakly antiferromagnetic.