Structures of Ag(I) Coordination Polymers Based on Fluorinated β-Diketones and Acetonitrile

Silver(I) coordination polymers are considered as components of antibacterial systems and precursors for preparing metallic and oxide nanoparticles for medical purposes. Mixed ligand complexes [Ag2(CH3CN)(L)2]∞ (L = ofhac (1,1,1,5,5,6,6,6-octafluoropentane-2,4-dionate), ptac (1,1,1-trifluoro-5,5-dimethylhexane-2,4-dionate), hfac (1,1,1,5,5,5-hexafluoropentane-2,4-dionate) are obtained by crystallization of respective silver(I) β-diketonates from acetonitrile or by direct neutralization of Ag2O with β-diketone in this solvent, and their structures are analyzed by single crystal X-ray diffraction. The compounds with L = ofhac, hfac are additionally characterized by NMR spectroscopy. The comparison of structures of the complexes with isoformula analogues shows that the formation of polymeric chains is characteristic of all compounds where structural blocks Ag(L)2 with chelating β-diketonate ligands are linked in pairs by Ag–Cα bonds with the methine carbon atom and are further linked by two silver atoms coordinating the solvent and having the {AgO2CαN} environment. The Ag–O, Ag–Cα, and Ag–N bond lengths vary in the ranges of 2.30-2.49 Å, 2.33-2.44 Å, and 2.17-2.23 Å respectively. The thermal properties of the complexes are investigated by the thermogravimetric analysis: complexes with fluorinated ligands L = hfac, ofhac are more thermally stable, and for L = ptac the step of acetonitrile removal is distinguished.