2016. 57, 5 – UDC 541.6:547.13:546.72:546.76 EXPERIMENTAL AND THEORETICAL CHARACTERIZATION . 923 – 931 OF Fe2Cr TRINUCLEAR-OXO-CENTERED COMPLEX WITH A CF2ClCOO– BRIDGE A. Morsali, S.A. Beyramabadi, H. Chegini, N. Bozorgi, A. Moghadam-Elahabad Department of Chemistry, Mashhad Branch, Islamic Azad University, Mashhad, Iran E-mail: almorsali@yahoo.com; morsali@mshdiau.ac.ir; beiramabadi@yahoo.com; beiramabadi6285@mshdiau.ac.ir Received November, 4, 2015 In this work, an atrinuclear-oxo-centered complex of the CrFe2 type with the CF2ClCOO– bridging ligand is newly synthesized. <...> The optimized geometry and theoretical vibrational frequencies are computed using the density functional theory (DFT) method. <...> Also, the AIM analysis was applied to study changes in topological parameters such as the electron density at critical points of all the bonds of the complex. <...> In the optimized geometry of the complex, three metal ions form a trigonal-planar structure with a 3-O atom in its center. <...> Each of M3+ metal ions has an octahedral coordination environment of oxygen atoms. <...> The DFT results are in agreement with the experimental ones, confirming the validity of the optimized geometry for the complex. <...> INTRODUCTION In the structure of thetrinuclear-oxo-centered complexes, an oxygen atom is located at the center of the atriangle generated by three metal ions. <...> Three monodentate ligands act as terminal ligands, too [ 1—4]. <...> The X-ray crystal structure of these compounds shows an essentially triangle arrangement of metal ions surrounding the central oxygen atom. <...> Antiferromagnetic coupling between metal ions and the electron delocalization in which metal forms a mixed-valence cluster have been extensively investigated [ 8—11 ]. <...> Herein, we report the synthesis and experimental characterization of a new trinuclear-oxocentered complex with the [Fe2Cr(3-O)(2-CF2ClCOO)6(H2O)3]NO3 formula. <...> The IR spectra were obtained on a Perkin Elmer 783 IR spectrophotometer. <...> All DFT calculations have been performed using the B3LYP functional [ 12 ] and 6-31G(d,p) basis sets. <...> Geometries of the synthesized complex were optimized in the gas phase, which were confirmed to have no imaginary frequency of the Hessian. <...> In the trinuclear-oxo centered complex of the carboxylic bridge (acetate group), Fe(III) ions have an octahedral surrounding with the high spin state: Fe(III) (S = 5/2) and Cr(III) (S = 3/2) [ 14 <...>