Synthesis and Characterization of Hydrogen-Bonded CobaltAmine-Disulfonate Extended Structures

The synthesis and characterization of hydrogen-bonded cobalt amine-disulfonate frameworks was attempted. Syntheses were carried out either through evaporation of aqueous mixtures of the starting materials or through slow diffusion of the starting materials in a two-solvent system. Crystals were successfully synthesized from four metal centers (Hexaamminecobalt, aquopentaaminecobalt, tris(ethylenediamine)cobalt and diaquobis(ethylenediamine)cobalt) and four organic linkers 1,2-ethanedisulfonate, 1,5-naphthalenedisulfonate, 2,6-naphthalenedisulfonate and 4,4'-biphenyldisulfonate). Four structures will be described and discussed herein. Three structures take on layered motifs. Compounds 1 and 2 form sheets of hexa and aquopentamminecobalt, respectively, that are interconnected by galleries of disulfonates. Compound 3 forms a layered structure of tris(ethylenediamine)cobalt sheets with two different disulfonate gallery arrangements, one of which forms one-dimensional channels. Compound 4 forms interconnected tubes of tris(ethylenediamine)cobalt with the disulfonates filling the interiors of the tubes. Compounds 2-4 display pi-pi interactions between disulfonates.Every structure is held together by hydrogen bonds and contains solvent guests.