Synthesis, Structural Characterization, and Biological Activities of Organically Templated Cobalt Phosphite (C₄N₂H₁₄)[Co(H₂PO₃)₄]·2H₂O

A novel hybrid phosphite (C₄N₂H₁₄)[Co(H₂PO₃)₄]·2H₂O was synthesized with 1,4- diaminobutane (dabn) as a structure-directing agent using slow evaporation method. Single crystal X-ray diffraction analysis showed that it crystallizes in the P\-1 triclinic space group, with the following unit cell parameters (Å, °) a = 5.4814 (3), b = 7.5515 (4), c = 10.8548 (6), α = 88.001 (4), β = 88.707 (5), γ = 85.126 (5), and V = 447.33 (4) ų. The crystal structure was built up from corner-sharing [CoO₆]-octahedrons, forming chains parallel to [001], which are interconnected by H₂PO₃⁻ pseudo-tetrahedral units. The diprotonated 1,4-butanediammonium molecules, residing between the parallel chains, interacted with the inorganic moiety via hydrogen bonds leading thus to the formation of the 3D crystal structure. The Fourier transform infrared spectrum showed characteristic bands corresponding to the phosphite group and the organic molecule. The thermal decomposition of the compound consisted mainly of the loss of the organic moiety and the water molecules. The biological tests exhibited significant activity against Candida albicans and Escherichia coli strains in all used concentrations, while less activity was pronounced when tested against Staphylococcus epidermidis and Saccharomyces cerevisiae, while there was no activity against the nematode model Steinernema feltiae.