The new heteronuclear1D polymer with the composition{[CuBa(CH3HSal)4(DMA)3]}n , where DMA=N,N-dimethylacetamide has been obtained by the reaction of copper nitrate with barium5-methylsalicylate [1]. X-ray analysis data has shown that the compound has a polymeric structure along the chain formed by copper and barium atoms linked through monodeprotonated 5-methylsalicylate ligands (Figure 1) and crystallizes intriclinic space group P-1 with the following unit cell parameters: a= 13.4311(12), b= 16.1521(8), c= 22.8719(17) (Å), a =87.088(5)º, b=89.821(7)º, y=73.229(6)º. Copper and barium atoms are displaced alternatively along the polymeric chain, thus each copper atom is linked to two different neighbouring barium atoms through four different carboxylate bridging groups (three carboxylate groups coordinate in a bidentate bridging μ2-n1:n1 mode and one carboxylate group in a tridentate bridging μ3-n1:n2 mode).Additionally the chain is decorated by three DMA molecules coordinated to each barium atom.Figure 1. View of the X-ray structure of the heteronuclear compound.The comparison of IR spectra of free 5-methylsalicylic acid and heteronuclear CuBa compound have confirmed the formation of a new coordinative compound. The adsorption bands corresponding to vas(COO-) and vs(COO-)can be observed at about1615.5cm-1and 1423.6 cm-1, respectively. The difference of ~200 cm-1 between the vas(COO-) and vs(COO-) bands indicates the bidentate-bridging mode of the carboxylate ligands coordination [2]. For the coordination compound, in the region of 3018.7-2922.9 cm-1 of the IR spectrum can be observed bands of medium intensity attributed to O-H vibrations; the band at ~1238.4 cm-1 was assigned to the C-O stretching frequencies of phenolic C-OH as observed for free 5methylsalicylic acid, thus confirming the fact that phenolic OH group is not involved in coordination.