Dipyrromethene-Triazolylidene Silver Complexes: Synthesis, Structure and Opportunities

The synthesis and characterization of unusual silver triazolylidene-containing dipyrromethene complexes are described. The carbeneTAD-N3C-Hobtained from its parent Triazole-Appended Dipyrromethene (TAD-N-4) is an excellent ligand for the complexation of silver, thanks to the proximity between the dipyrromethene scaffold and the triazolylidene. The effect of silver salt stoichiometry on the structure of the complexes was clearly evidenced by(1)H-NMR spectroscopy and mass spectrometry. Furthermore, an unexpected argentophilic interaction was proved by different analytical techniques, including X-ray diffraction analysis and fluorescence spectroscopy. The potentiality of using the unprecedented DPM-triazolydene silver complexes for the preparation of dipyrromethene-based metallocomplexes displaying unusual coordination mode was further demonstrated with palladium.