Synthesis, Structures, and Thermal Behavior of Calcium, Strontium, Barium Bis(1-ferrocenyl-4,4,4-trifluorobutane-1,3-dionato) Complexes with Crown-Ethers

The new ferrocenyl-containing β-diketonate complexes with crown-ethers [Ca(Fctfa)2(15-crown-5)] (I), [Sr(Fctfa)2(18-crown-6)] (II), [Sr(Fctfa)2(18-crown-6)](CH2Cl2) (III), [Ba(Fctfa)2(18-crown-6)] (IV) and [Ba(Fctfa)2(18-crown-6)](CH2Cl2) (V) (Fctfa = 1-ferrocenyl-4,4,4-trifluorobutane-1,3-dionato), 15-crown-5 = 1,4,7,10,13-pentanoxacyclopentadecane; 18-crown-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane) have been synthesized. The compounds are characterized by infrared and 1H NMR spectroscopy and X-ray diffraction analysis. The thermal behavior of complexes I, II, IV was investigated by thermal analysis. It was found that complexes are thermally stable up to 150°C for I, 215°C for II 180°C for IV. The decomposition behavior of I, II, IV studied by 1H nuclear magnetic resonance investigation of substances, formed at decomposition of I, II, IV in dynamic vacuum. It was found, that the heating of I, II, IV in the ranges 150–800°C for I, 215–800°C for II, 180–800°C for IV affords the solid substances, containing alkaline-earth metals fluorides and iron oxides. Using topological analysis of the electron density distribution in I, III, V, intra- and intermolecular interactions were quantitatively estimated within the framework of Bader’s atoms in molecules theory. According to Espinosa–Mollins–Lecomte correlation, energies of the intermolecular interactions for I, III, V are close to the experimentally measured enthalpies of sublimation of related complexes published previously.