Silver(I) Complexes of Schiff Bases Derived from Thiophene-2,5-dicarboxaldehyde and Furan-2,5-dicarboxaldehyde
作者:Wen-Shu Hwang、Dong-Liang Wang、Sen-T'sing Hsu、Ling-Kang Liu
DOI:10.1002/jccs.199800043
日期:1998.4
AbstractThe reactions of Schiff bases, derived by the condensation of thiophene‐2,5‐dicarbaldehyde and furan‐2,5‐dicarbaldehyde with 2‐thienylmethylamine or 2‐furanmethylamine, with silver nitrate have been studied in refluxing anhydrous methanol under nitrogen atmosphere. Complexes thus formed have been isolated and characterized by elemental analysis, electrical conductance, cyclic voltammetry, and 1H NMR, 13C NMR, IR, LTV‐Vis, and mass spectroscopic studies. The experimental results reveal that the complexes are primarily ionic in nature, consisting of (L)3Ag2 dication and Ag(NO3)3 negatively charged dianions. The molecular structure of one of the complexes, [((C4H3O)CH2NCH(C4H2S)CHNCH2(C4H3O))3Ag2] [Ag(NO3)3] has been studied in the solid state. The complex is crystallized in the triclinic space group \documentclassarticle}\pagestyleempty}\begindocument}$ \rm P}\bar 1 $\enddocument} with a = 12.889(7) Å, b = 14.884(5) Å, c = 15.084(6) Å, α = 92.18(4)°, β = 79.78(4)°, γ = 110.92(4)°. The structure is disordered. Each Ag in dication is tri‐coordinated by three azomethine N atoms from three ligands, and each ligand employs two azomethine N atoms to coordinate to two Ag ions such that the geometry around the Ag ⃜Ag axis conforms to a propeller‐shape. The two Ag ions are between the two N3 planes with Ag ⃜ Ag distance ca. 4.8.1 Å. There is no bonding between any Ag ion and any thiophene of the three ligands. However, two Ag ions and three thiophene S atoms form a trigonal bipyramidal geometry.