Structural studies of molecular-based nanoporous materials. Novel networks of silver(I) cations assembled with the polydentate N-donor bases hexamethylenetetramine and 1,3,5-triazine

Novel polymeric materials have been isolated from the reactions of silver(I) salts of poorly coordinating anions with the polydentate bases hexamethylenetetramine (hmt) and 1,3,5-triazine (trz), the one-dimensional polymer [Ag(hmt)] SbF6 . H2O 1, and the three-dimensional networked compounds [AG(11)(hmt)(6)][PF6](11). 14H(2)O 2 and [Ag-6(trz)(8)][BF4](6) . H2O 3, characterized by single-crystal X-ray analysis. Compound 1 is monoclinic, space group P2(1)/n, a=14.252(4), b=11.061(8), c=16.450(8) Angstrom, beta= 90.17(3)degrees. The structure contains a novel type of ribbon formed by hexagonal meshes of alternate Ag-I ions and hmt molecules. The water molecules coordinated to the silver ions form hydrogen bonds which generate a three-dimensional network of unprecedented topology. Crystals of 2 are monoclinic, space group 12, a=19.552(6), b=10.856(6), c=25.749(11) Angstrom, beta=92.83(3)degrees. It consists of an open three-dimensional network of complex topology with all the hmt molecules tetraconnected. Out of the eleven independent Ag-I ions per formula unit, nine are biconnnected and two triconnected to the hmt bases. The large channels in the network contain many water molecules. Compound 3 is monoclinic, space group P2(1)/c, a=12.535(8), b=29.517(8), c= 14.703(6) Angstrom, beta=93.95(4)degrees. The structure contains six independent Ag ions and eight independent triazine molecules, which display varied connectivities to give a puzzling three-dimensional network.