A Dinuclear Double-Stranded Oxido Complex of Re-V with a Bis(benzene-o-dithiolato) Ligand

作者：Gancheff Jorge S; Albuquerque Rodrigo Q; Guerrero Martinez Andres; Pape Tania; De Cola Luisa; Hahn F Ekkehardt^*

来源：European Journal of Inorganic Chemistry, 2009, 2009(27): 4043-4051.

DOI：10.1002/ejic.200900496

• Oxido complexes
• Rhenium(V)
• Double-stranded complexes

The reaction of [ReOCl3(PPh3)(2)] with 1,2-bis(2,3- dimercaptobenzamido)ethane (H-4-1) in the presence of Na2CO3 in methanol under anaerobic conditions affords the dinuclear Re-V oxido complex [PPh4](2)[ReO(1)](2) containing two distorted square-pyramidal {(ReOS4)-O-V} units bridged by the ligand strands in a double-stranded fashion. The coordination geometry around the metal centers is similar to the one observed for [ReO(bdt)(2)](-). The ReS4 planes are arranged in a coplanar fashion and are not twisted around the metal-metal vector, which prevents the complex to adopt a helical structure. Luminescence studies show the presence of emission bands, which are assigned to singlet-singlet transitions exhibiting very fast decays (ca. 10 ns). Theoretical Density Functional (DFT) studies on geometry and electronic properties were performed employing the hybrid B3LYP and PBE1PBE functionals. While the general trends observed in the experimental data are well reproduced in all cases, a good agreement was obtained using PBE1PBE, in particular for the Re-S bonds. Natural Bond Orbitals (NBO) analysis indicates the presence of polarized Re O and Re-S bonds, both of them polarized toward the non-metal. The calculation show that the molecular orbitals of the Rev are doubly degenerated, the occupied 5d orbital of rhenium lying beneath occupied sulfur-based MOs due to the rigid geometry imposed by the CC backbone of the bis (benzene-o-dithiolato) ligands. The origin of all absorption bands is ascribed to a ligand-to-metal charge transfer (LMCT), in which occupied sulfur-based orbitals and unoccupied rhenium-centered orbitals are involved.

• 出版日期2009-9