Group 11 complexes with imidazoline-2-thione or selone derivatives

The reactions of the organodichalcogenone ligands Bbit [1,1'-(butane-1,4-diyl)bis(3-methylimidazoline-2-thione)], Mbis [1,1'-methylenebis(3-methylimidazoline-2-selone)], Ebis [1,1'-(ethane-1,2-diyl)bis(3-methylimidazoline-2-selone)] and Pbis [1,1'-(pentane1,5-diyl)bis(3-methylimidazoline- 2-selone)] with gold(I/III), silver(I) and copper(I) have been studied by elemental analysis, multinuclear (1H, 13C,19F, 31P and 77Se) NMR spectroscopy and for several products obtained the molecular structures were also established by single-crystal X-ray diffraction analysis. In most cases the organodichalcogenone coordinates to two metallic fragments as a bidentate bridging ligand but the ligand Mbis coordinates to silver(I) in an unprecedented tetradentate bridgingchelate mode

Homopolynuclear Tl(I) and heteropolynuclear Au(I)-Tl(I) complexes with organodiselone ligands: activation of the luminescence by intermetallic interactions

The organodiselone ligands 1,1-bis(3-methyl-4-imidazolin-2-selone)methane (L1) and 1,2-bis(3-methyl-4-imidazolin-2-selone)ethane (L2) have been used for the synthesis of homopolynuclear TlI [{Tl(L)}PF6]n·(mMeCN)n [L = L1, m = 1 (1); L = L2, m = 0 (2)] and discrete heteropolynuclear [Tl{Au-(C6Cl5)2}(L)] [L = L1 (3), L2 (4)] complexes. The crystal structures of complexes 1 and 3 have been determined through X-ray diffraction studies. Complex 1 consists of alternating thallium(I) centres and bidentate Se-donor ligands that result in polymeric chains. The crystal structure of 3 is formed by [Tl(L1)]+ cations and [Au(C6Cl5)2]– anions joined together by an unsupported Au···Tl interaction. Compounds 3 and 4 are luminescent in the solid state at room temperature and at 77 K with lifetimes in the nanosecond range. DFT and time-dependent (TD)-DFT calculations have been carried out on different model systems including the free ligand L1, a representative model of complex 1 and a model system of complex 3. The character of the frontier molecular orbitals and the TD-DFT prediction of the absorption spectra are used to explain the origin of the luminescence of complexes 3 and 4 as an admixture of metal–metal (Au–Tl)-to-ligand charge transfer(MMLCT) and intraligand (IL) transitions as observed experimentally