Rational synthesis and characterization of two three-dimensional metal-organic frameworks incorporating silver chains and 1,2,3,4,5,6- cyclohexanehexacarboxylate

Abstract

Two new silver polycarboxylate coordination polymers, [Ag 3(H3L)(H2O)2]n· 2nH2O (1) and [Ag6L(NH3)(H2O) 3]n·nH2O (2), have been obtained from the reaction of [Ag(NH3)2](OH) (freshly synthesized from Ag2O and aqueous ammonia) with cis,cis,cis,cis,cis-1,2,3,4,5,6- cyclohexanehexacarboxylic acid (H6L) by control of the molar ratio of starting materials. The X-ray crystal structure analysis reveals that both of them crystallize in the triclinic space group P1 with a = 6.375(4), b = 9.505(6), c = 15.097(8) Å, α = 93.249(14), β = 100.364(15), γ = 96.453(15)°, V = 891.4(9) Å3, Z = 2 for 1, and a = 8.0380(7), b = 10.1220(9), c = 13.8458(12) Å, α = 76.3450(10), β = 80.9370(10), γ = 68.7230(10)°, V = 1016.83(15) Å3, Z = 2 for 2. Complex 1 features a three-dimensional (3D) metal-organic framework (MOF) with one-dimensional (1D) rectangular channels surrounded by carboxylato-supported Ag-Ag dimers, Ag-Ag chains, and half deprotonated [H3L]3- ligands. Each [H3L] 3- ligand connects eight AgI atoms. The weakly coordinated water ligands and lattice water molecules are located at the channels and form interesting 1D hydrogen-bonded T4(2)8(2) water tapes with cyclic R 86(16) (H2O)8 and R44(8) (H2O)4 units. Complex 2 is also a 3D MOF structure constructed by two types of Ag-Ag chains with Ag8 cluster units and linear Ag4 units, respectively, and fully deprotonated L6- ligands. The silver(i) atoms in 2 exhibit linear, T-shaped, Y-shaped, and tetrahedral coordination geometries. Each L6- ligand connects thirteen Ag I atoms. The intrachain robust argentophilic interactions play a vital role in the formation of the structure. © Wiley-VCH Verlag GmbH & Co. KGaA, 2006.