By the reaction of copper nitrate with barium salycilate in methanol at constant stirring and room temperature, the blue powder was obtained. By recrystallization of this product from the mixture of solvents dimethylacetamide (DMAA) and tetrahydrofuran (THF) the crystals of new complex of the composition [CuBa(SalH)4(DMAA)4(H2O)] (1) of intense blue colour were obtained. The X-ray investigation of monocrystal of this substance has demonstrated that this complex has a dimer structure of “lantern” type. Four bidentate carboxylate bridged groups link copper and barium atoms in dimer. The coordination number of Cu is five (4+1) and Ba is 8 (Fig. 1). In the crystal by hydrogen bonds dimmer complex forms the polymer structure.figure 1figure 2Fig.1. The molecular structure of 1. Fig.2. The EPR spectrum of a single crystal 1 at H┴σ and T = 300K. The EPR spectrum of 1 corresponds to his molecular structure presented on Fig. 1. It is caused by Cu 2+ ions (the electron configuration 3d 9 and spin S=1/2) being components of Cu 2+ -Ba 2+ dimmers (the ion Ba 2+ haven’t a spin). Fig. 2 shown the room-temperature EPR spectrum at H⊥σ (σ is the big side of the crystal) with the well solved hyperfine structure (I=3/2 for bots 63Cu and 65Cu isotopes with 69.09% and 30,091% natural abundance, correspondingly). At H║σ the EPR spectrum it is transformed into a single line without hyperfine structure. In summary, it is the new dimmer compound, which contain copper (II) and s-element.