Two cadmium(II) fluorous coordination compounds tuned by different bipyridines

Fluorine is the most electronegative element and can be used as an excellent hydrogen-bond acceptor. Fluorous coordination compounds exhibit several advantageous properties, such as enhanced high thermal and oxidative stability, low polarity, weak inter­molecular inter­actions and a small surface tension compared to hydro­carbons. C—H⋯F—C inter­actions, although weak, play a significant role in regulating the arrangement of the organic mol­ecules in the crystalline state and stabilizing the secondary structure. Two cadmium(II) fluorous coordination compounds formed from 2,2′-bi­pyridine, 4,4′-bi­pyridine and penta­fluoro­benzoate ligands, namely catena-poly[[aqua­(2,2′-bi­pyridine-κ2N,N′)(2,3,4,5,6-penta­fluoro­benzoato-κO)cadmium(II)]-μ-2,3,4,5,6-penta­fluoro­benzoato-κ2O:O′], [Cd(C7F5O2)2(C10H8N2)(H2O)]n, (1), and catena-poly[[di­aqua­bis­(2,3,4,5,6-penta­fluoro­benzoato-κO)cadmium(II)]-μ-4,4′-bi­pyridine-κ2N:N′], [Cd(C7F5O2)2(C10H8N2)(H2O)2]n, (2), have been synthesized solvothermally and structurally characterized. Compound (1) shows a one-dimensional chain structure composed of Cd—O coordination bonds and is stabilized by π–π stacking and O—H⋯O hydrogen-bond inter­actions. Compound (2) displays a one-dimensional linear chain structure formed by Cd—N coordination inter­actions involving the 4,4′-bi­pyridine ligand. Adjacent one-dimensional chains are extended into two-dimensional sheets by O—H⋯O hydrogen bonds between the coordinated water mol­ecules and adjacent carboxyl­ate groups. Moreover, the chains are further linked by C—H⋯F—C inter­actions to afford a three-dimensional network. In both structures, hydrogen bonding involving the coordinated water mol­ecules is a primary driving force in the formation of the supra­molecular structures.