title: Synthesis, X-ray structure, polarized optical spectra and DFT theoretical calculations of two new organic-inorganic hybrid fluoromanganates(III): (bpaH2)[MnF4(H2O)2]2 and (bpeH2)[MnF4(H2O)2]2.
abstract: Two new fluoromanganates(III) of 1,2-bis(4-pyridyl)ethane (bpa) and trans-1,2-bis(4-pyridyl)ethylene (bpe), LH(2)[MnF(4)(H(2)O)(2)](2) (L = bpa or bpe), have been prepared and their structure have been solved by single-crystal X-ray diffraction. The [MnF(4)(H(2)O)(2)](-) anion displays an octahedral geometry with a strong Jahn-Teller tetragonal distortion along the H(2)O-Mn-OH(2) axis. The equatorial metal-ligand distances (Mn-F 1.827(1)-1.859(2) A) are shorter than the axial ones (Mn-O 2.203(2)-2.234(2) A). Three polarized absorption bands at 22,500, 18,300 and 14,500 cm(-1) are observed in the optical spectra of (bpaH(2))[MnF(4)(H(2)O)(2)](2). Finally, we present theoretical calculations on the equilibrium bond distances as well as the crystal-field electron structure using density functional methods. The calculated Mn-F bond distances (1.85 A) are in agreement with the experimental data but the obtained Mn-O distances (2.53-2.56 A) are higher than the experimental one as usually found in similar Jahn-Teller distorted systems. The calculated d-d transition energies are compared with experimental energies derived from the optical spectra. The variation of the HOMO energy and transition energies against the Mn-O distance is also shown.
authors.affiliation: Departamento de Química Inorgánica, Universidad de La Laguna, 38200 La Laguna, Tenerife, Canary Islands, Spain. pnunez@ull.es
authors.forename: Pedro
authors.initials: P
authors.lastname: Núñez
authors.forename: Juan C
authors.initials: JC
authors.lastname: Ruiz-Morales
authors.forename: A D
authors.initials: AD
authors.lastname: Lozano-Gorrín
authors.forename: Pedro
authors.initials: P
authors.lastname: Gili
authors.forename: Vicente D
authors.initials: VD
authors.lastname: Rodriguez
authors.forename: J
authors.initials: J
authors.lastname: González-Platas
authors.forename: Teresa
authors.initials: T
authors.lastname: Barriuso
authors.forename: Fernando
authors.initials: F
authors.lastname: Rodríguez