Homoleptic copper(I) and silver(I) complexes [M(n)(L-L)(2n)](BF4)(n) (M = Cu or Ag; L-L = MeECH(2)EMe; E = S, Se or Te) have been prepared and characterized by analysis, FAB mass spectrometry, and IR and multinuclear NMR spectroscopy (H-1, Se-77, Te-125, Cu-63 and Ag-109). The single-crystal X-ray structures of [Cu-n(MeSeCH(2)SeMe)(2n)](PF6)(n) (orthorhombic, P2(1)2(1)2(1), a 10.879(7) Angstrom, b = 16.073(7) Angstrom, c = 9.19(1) Angstrom, Z = 4) and [Ag-n(MeSeCH(2)SeMe)(2n)](BF4)(n) (monoclinic, P2(1)/c, a 14.546(9) Angstrom, b = 14.65(1) Angstrom, c 30.203(9) Angstrom, Z = 4) reveal extended three-dimensional cationic frameworks in the solid state which contain large cylindrical or rectangular channels accommodating the PF6- or BE(4)(-) counterions. In contrast, a single-crystal X-ray structure of [Cu-n(MeSCH(2)SMe)(2n)](PFs)(n) . nMeNO(2) (orthorhombic, Pbcn, a 15.506(3) Angstrom, b = 8.934(2) Angstrom, c = 25.859(3) Angstrom, Z = 8) shows tetrahedral Cu(I) ions coordinated to bridging dithioethers forming an cationic ribbon-like arrangement of 8-membered rings. Adjacent rings are linked by the Cu atoms. Variable temperature NMR studies have been used to probe various exchange processes occurring in solution in these systems.