Syntheses, spectroscopy and crystal structure of several binuclear silver(I) cryptates

Abstract

Three binuclear silver(I) cryptates were synthesized by template condensation of tris(3-aminopropyl)amine with 5-R-2- methoxy-l,3-phenylenedialdehyde (R=CH 3O, CH 3 or Br) and characterized by physical measurements (solution electrical conductivity, 1H NMR, IR and electronic spectra). The crystal structure of the cryptate of L 1 (R=CH 3O) was determined by X-ray diffraction and presents a novel basket structure for the cation [Ag 2L 1] 2+ in which both silver(I) centres possess three coordinate environments. The crystal is monoclinic, space group Cc, C 48H 68Cl 2N 8O 15Ag 2, M r=1283.75, a=11.349(2), b=29.16(1), c=17.506(6) Å, β=102.38(2)°, Z=4, R=0.063 and R w=0.071 for 3693 reflections. Each Ag atom locates at the top of a trigonal pyramid distorted from a planar triangle composed of one bridgehead tertiary nitrogen and two imino nitrogens. Only two bridging chains of the cryptand coordinate to the metals, another does not. The internuclear distance Ag(1)···Ag(2) is 7.468(12) Å. All cryptates possess similar spectroscopic features.