Square-planar and trigonal prismatic silver(I) in bipyrimidine and oxalate bridged tetranuclear complexes and one-dimensional compounds: Synthesis and crystal structures

The reaction of [Ag4(hfac)4(THF)2] (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate, THF = tetrahydrofurrane) with 2,2′-bipyrimidine (bpm) leads to single crystals. They crystallise in the triclinic system, space group P1¯. Their structure consists of [Ag4(hfac)4(μ2-bpm)3] tetranuclear complexes. In this complex, Ag(I) ions adopt distorted square planar and trigonal prismatic geometries. When [Ag4(hfac)4(THF)2] is replaced by monohydrated silver(I) perchlorate, a one-dimensional (1D) compound with a formula of [[Ag(μ2-bpm)]+]n, nClO4- is obtained as single crystals. They crystallise in the monoclinic system, space group P21/c. Their structure consists of [[Ag(μ2-bpm)]+]n chains separated by non-coordinated perchlorate ions. In the chains, the Ag(I) centres adopt a square planar geometry. Finally, starting from [[Ag(μ2-bpm)]+]n, nClO4- and sodium oxalate (Na2ox;ox=C2O42-), another 1D compound with a formula of [Ag(μ2-bpm)(μ2-ox)]n, 4nH2O is obtained as single crystals. They crystallise in the triclinic system, space group P1¯. In these chains, bipyrimidine and oxalate are alternate. They generate a square planar geometry around the Ag(I) cations.

Three syntheses implying silver(I) ion and 2,2′-bipyrimidine (bpm) are explored. To favour the reaction of bpm, silver(I) is introduced either activated by a perfluorated ligand or combined with a weakly coordinating counter-ion. In the former case, it leads to the formation of tetranuclear complexes. In the latter case, one-dimensional (1D) compounds are obtained.Figure optionsDownload as PowerPoint slide