Homoleptic Copper(I) and Silver(I) Complexes with <i>o</i>-Phenylene-Backboned Bis(thioethers), Bis(selenoethers), and Bis(telluroethers):  Synthesis, Multinuclear NMR Studies, and Crystal Structures of [Cu{<i>o</i>-C₆H₄(SeMe)₂}₂]PF₆, [Cu{<i>o</i>-C₆H₄(TeMe)₂}₂]PF₆, and [Ag<i>_n</i>{μ-<i>o</i>-C₆H₄(SeMe)₂}<i>_n</i>{<i>o</i>-C₆H₄(SeMe)₂}<i>_n</i>][BF₄]<i>_n</i>·<i>n</i>CH₂Cl₂

Abstract

Homoleptic copper(I) and silver(I) complexes [M(L-L) 2 ]X (M = Cu, X = PF 6; M = Ag, X = BF 4; L-L = o -C 6 H 4 (EMe) 2; E = S, Se, Te) have been prepared and characterized by analysis, FAB mass spectrometry, and multinuclear NMR spectroscopy ( 1 H, 77 Se, 125 Te, 63 Cu, 109 Ag). Variable-temperature NMR studies have been used to probe various exchange processes occurring in solution. Single-crystal X-ray structural studies show that the Cu(I) complexes [Cu{ o -C 6 H 4 (SeMe) 2 } 2 ]PF 6 [trigonal, a = 13.29(2), c = 65.97(2) Å, R 3̄ c, Z = 18] and [Cu{ o -C 6 H 4 (TeMe) 2 } 2 ]PF 6 [trigonal, a = 13.632(6) Å, c = 67.983(4) Å, R 3̄ c, Z = 18] are isostructural and exist as mononuclear species with chelating bis(seleno- and bis(telluroethers), respectively, whereas the single-crystal structure of [Ag{ o -C 6 H 4 (SeMe) 2 } 2 ]BF 4 [monoclinic, a = 19.273(7) Å, b = 11.927(3) Å, c = 20.405(6) Å, β = 90.42(3)°, P 2 1 /c, Z = 4] comprises infinite chains of [Ag n {μ- o -C 6 H 4 (SeMe) 2 } n { o -C 6 H 4 (SeMe) 2 } n ] n +, discrete BF 4 -, anions and CH 2 Cl 2 solvent molecules. The o -C 6 H 4 (SeMe) 2 ligands in the latter exist as a mixture of invertomers within the infinite chains; the chelating ones adopt the meso arrangement while the bridging ones occur as the dl form. This is the first structurally characterized complex involving a bridging o -phenylene group 16 donor ligand and the first case of both invertomers occurring in a single complex.