A variety of types of polynuclear 3d-metal benzoates leads us to the idea of obtaining similar complexes with derivatives of benzoic acid, in particular with o-methylbenzoic (otoluilic) acid in order to study the effect of substituent in benzene ring on the structure and types of the compounds. Whereas iron containing complexes make it possible to investigate the electron environment around metal centers by Mössbauer spectroscopy, we have first studied trinuclear complex of iron(III). Novel homotrinuclear complex featuring a {Fe3(μ3-O)} core and toluilate ligands has been synthesized and structurally characterized by single crystal X-ray method at 100K. It was found that the formation of a crystalline product is well reproducible only in the presence of a small amount of N,N-dimethylacetamid (DMAA). The compound with composition [Fe3O(tol)6(CH3OH)1.5(H2O)1.5]NO3(DMAA)(H2O)(CH3OH), where tol denotes monodeprotonated o-toluic acid, crystallizes in the triclinic space group P-1, a=11.8431(7), b=13.1096(8), c=21.8748(15) Å, α=100.948(7), β=98.164(7), γ=114.333(6)°, V=2944.7(3)Å3 . In the structure of this complex (Fig.1) Fe3+ ions occupy the vertexes of isosceles triangle, Fe1 …Fe2 and Fe1 …Fe3 distances is similar and equal 3.3082(9), 3.3025(9)Å, respectively while Fe2 …Fe3 distance is 3.278(1)Å. The center of the triangle is occupied by the μ3-O atom, which is coplanar with the metal core.figureFig.1. Molecular structure (a) and Mossbauer spectrum (b) of investigated complex The iron ions have an octahedral coordination surrounding provided by four O atoms of four bridging toluilate ligands, central μ3-oxo atom and external monodentate ligand, which are water molecule on Fe1, methanol molecule on Fe2. Water or methanol molecules statistically occupy the apical position of Fe3 with equal probability. In the Mossbauer spectrum of crystalline sample at 80 K consists of two broad peaks which was fitted by two doublets (SrelI=0.46; SrelII=0.50), with the parameters, mm/s: D1: ISFe=0.53, QS=0.40, G=0.42; D2: ISFe=0.53, QS=0.54, G=0.34. They correspond to the highspin iron (III) (S=5/2) states but with slightly different value of electric field gradient. This fact is consistent with the X-Ray data.