A Mild Synthetic Route to Zinc, Cadmium, and Silver Polymers with (2-Pyridyl)phosphonic Acid: Synthesis and Analysis



Five new metal pyridylphosphonate polymers have been prepared, fully characterized, and their room-temperature luminescence probed. The reaction of (2-pyridyl)phosphonic acid (2pypo) with ZnX2 (X = Br, Cl) afforded two-dimensional polymers [Zn(X)(2pypo)]n {X = Cl = (1), X = Br = (2)}, which feature cyclic 12-membered Zn–O–P cores that are interlinked by bridged oxygen atoms from the phosphonate moiety. From the room–temperature, aqueous reactions of 2pypo and the corresponding metal salts, the one-dimensional polymers [Cd(μ-Cl)2(2pypo)]n (3) and [Hg(2pypo)]n (4) were isolated in moderate yield. The one-dimensional structure of 3 is supported through bridging chlorides and two η2-phosphonate oxygen atoms, while 4 is a highly symmetrical polymer that exhibits pyridyl nitrogen coordination to the mercury center and uses two μ2-oxygen atoms to polymerize. Reaction of silver triflate (CF3SO3Ag) with 2pypo afforded a crystalline silver polymer that displays a zig-zag arrangement of silver atoms with argentophilic interactions and that is stablized through bridged triflate and phosphonate moieties. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)