A silver complex with ibuprofen: Synthesis, solid state characterization, DFT calculations and antibacterial assays

The present work describes the synthesis of a silver(I) complex with the non-steroidal anti-inflammatory ibuprofen, Ag-ibu. Elemental and thermal analyses indicate a 1:1 metal/ligand composition. Thermogravimetric analysis shows that Ag-ibu decomposition starts at 180 °C, and ends at 400 °C (mass loss 64.6%; calcd. 65.5%). UV/Vis kinetic measurements suggest the decomposition of Ag-ibu in dimethyl sulfoxide, with the appearance of a broad band in the spectrum of the complex in the range 300–500 nm. Infrared and solid state 13C NMR spectra show the coordination of ibuprofen to silver through the carboxylate group. The DFT calculations led us to propose a dimeric silver bridging structure for the complex. Biological studies show the antibacterial activity of the Ag-ibu complex against Gram-positive and Gram-negative bacterial strains, with MIC values ranging from 6.25 to 12.5 μg mL−1.