Insights into the structure of triethylammoniumbis(pyridine-2,6-dicarboxylato-iron(III)) Crystallographic and theoretical study
Résumé
A synthesis of Fe(III) dipicolinate complex leads to a new crystalline structure of triethylammonium bis(pyridine-2,6-dicarboxylato-iron(III)). This latter has been determined by single crystal X-ray diffraction analysis, and FT-IR spectroscopy. The title compound crystallizes in space group P-1 of triclinic system with cell parameters a = 7.9288(6) angstrom, b = 10.5262(9) angstrom, c = 14.2351(12) angstrom, = 72.552(3)degrees, = 86.769(3)degrees, = 70.266(3)degrees. The asymmetric unit contains an [Fe(pydc)(2)] (pydc = pyridine-2,6-dicarboxylate) anion and a protonated triethylamine as a conter-ion. Fe ion is coordinated to two perpendicular tridentate ligands in their dianionic form (pydc(2-)). In addition, the cation and the anion are involved in an extensive three-dimensional hydrogen-bond network which collaborates to the stabilization of the 3D supramolecular structure. The molecular structure was calculated using DFT/B3LYP method at 6-31G(d,p) basis set. The calculated results show that the optimized geometry reproduces well the crystal structure. Electronic chemical potential (mu), chemical hardness (), electrophilic () and nucleophilic (N-u) descriptors of the title molecule have also been determined. Finally, Fukui functions (f(k)(+) and f(k)(-)) and local nucleophilicity (N-uk) indexes were calculated and have been then evaluated. [GRAPHICS]