Inorganic Chemistry, Vol.42, No.5, 1637-1643, 2003
Assembly of discrete, one-, two-, and three-dimensional silver(I) supramolecular complexes containing encapsulated acetylide dianion with nitrogen-donor spacers
The first successful attempt to construct supramolecular entities via incorporation of bifunctional exodentate ligands into the silver acetylicle system is reported. Coordination assembly with nitrogen-donor spacers led to the formation of five distinct supramolecular complexes, namely [(Ag2C2)(AgCF3CO2)(4)(PYZ)(2)], (1), [(Ag2C2)(2)(AgCF3CO2)(10)(CF3CO2)(4)(DabcoH)(4)(H2O)(1.5)].H2O (2), [(Ag2C2)(AgCF3CO2)(4)(CF3CO2)(bpaH)], (3), [(Ag2C2)(AgCF3CO2)(8)(bpa)(4)], (4), and [(Ag2C2)(2)(AgCF3CO2)(10)(bppz)(2)(H2O)](n) (5) (pyz = pyrazine; Dabco = 1,4-diazabicyclo[2.2.2]octane; bpa = 1,2-bis(4-pyridyl)ethane; bppz = 2,3-bis(2-pyridyl)pyrazine). Complex 1 is a three-dimensional framework composed of silver columns cross-linked by pyrazine bridges, whereas 2 contains a discrete supermolecule whose core is a Ag-14 double cage that is completely surrounded by trifluoroacetate, aqua, and terminal monoprotonated Dabco ligands. Complex 3 has a branched-tree architecture with one terminal of the bpa ligand attached to the silver backbone and the other exposed and protonated. In 4, neutral decanuclear [(Ag2C2)(AgCF3CO2)(8)] units are interlinked by bpa spacers adopting both gauche and anti conformations to generate a layer structure. Another two-dimensional network was formed with bppz serving as an angular bridging ligand in 5, in which the building unit is a silver quadruple cage containing 24 silver atoms.