Synthesis, X-ray investigation and DFT calculations of solvated barium β-diketonate complexes with 18-dibenzocrown-6: [Ba(pta)2(18DBC6)](C6H5CH3)2 and [Ba(pta)2(18DBC6)](CH2Cl2) (pta = 1,1,1-trifluoro-5,5-dimethylhexanedionato-2,4; 18DBC6 = 18-dibenzocrown-6)

Abstract

The complexes [Ba(pta)2(18DBC6)](C6H5CH3)2 (1) and [Ba(pta)2(18DBC6)](CH2Cl2) (2) (pta=5,5-dimethyl-1,1,1-trifluoro-hexanedionate-2,4; 18DBC6=6,7,9,10,17,18,20,21-octahydrodibenzo[b,k]-[1,4,7,10,13,16]-hexaoxacyclooctadecane) have been prepared by the reaction of metallic barium with 18DBC6 and excess of Hpta in ethanol or a methanol-toluene mixture, respectively. 1 and 2 were characterized by elemental analysis, IR and 1H NMR spectroscopy, and using the single crystal X-ray diffraction method. Examination of the molecular structures of 1 and 2 show them to have monomeric structures; in both compounds the coordination environment of the Ba atom is composed of six O atoms of the 18DBC6 ligand and four O atoms two pta ligands; the pta ligands are disposed in cis positions relative to the plane of 18DBC6. The electronic structures of the non-solvated molecules with different geometries are compared with use of DFT and electron density distribution analysis.