Single strands versus ladders: Construction of skeletal structure via coordinating ability of anions

The construction of skeletal structure via coordinating ability of anions is described. The characteristics of anions such as negative charge, size, a wide range of geometries, significant solvent effects, and pH dependence play key roles in determining the molecular skeleton and behaviors. All the compounds are insoluble in water and common organic solvents but dissociated in acetonitrile, dimethyl sulfoxide, and N,N-dimethyformamide. In addition, these products are air-stable but slowly turned to gray powder under light. The anions at the surface of the molecular strands can be exchanged in a typical aqueous media. The reaction mixture was refluxed for 24 h. The solution was filtered, and then the filtrate was washed with 0.5 N NaOH and water several times. The reverse exchange, however, was not easily carried out under the same conditions. The reverse exchange reaction is unfavorable both in entropy and water-solubility.