One-dimensional coordination polymers of silver(I) with aminomethylpyridines. Example of a triple helical infinite chain

Crystal structures of the three isomeric compounds Ag(2amp)ClO4 (1), Ag(3-amp)ClO4 (2), and Ag(4-amp)ClO4 (3) reveal different packing arrangements of one-dimensional (1-D) infinite chain coordination polymers, formed in each case by the coordination of Ag to the pyridine N and amino N atoms from two different ligand molecules. 1: triclinic, space group P (1) over bar, with a = 7.672(6) Angstrom, b = 11.1401(11) Angstrom, c 11.322(4) Angstrom, alpha = 91.207(14)degrees, beta = 105.52(4)degrees, gamma = 90.48(2)degrees, and Z = 2. 2: monoclinic, space group P2(1)/c, with a 8.345(4) Angstrom, b = 8.6748(7) Angstrom, c = 26.056(9) Angstrom, beta = 97.96(4)degrees, and Z = 4. 3: hexagonal, space group P6(5)22, With a 9.3154(11) Angstrom, c = 39.313(5) Angstrom, and Z = 12. 1 consists of zigzag chains, while 2 is made up of triple helical chains generating a tunnel space large enough to hold half the anions inside it. 3 has a highly symmetrical arrangement of 12 crystallographically equivalent chains held by weak Ag ... Ag bonds. The crystal packing of the 1-D polymers in this case may be described in terms of either helical ladders or stacked double layers.