Synthesis, characterization and mechanochromic behavior of binuclear gold (I) complexes with various diisocyano bridges

A series of binuclear gold (I) complexes were synthesized. Their structures were characterized by elemental analyses, IR spectrometry, UV–Vis spectroscopy and single crystal X-ray diffraction. Their fluorescent mechanochromic (tribochromic) properties were investigated. The results of the mechanochromic studies suggested that the gold complexes with methylsubstituted phenyl bridges exhibited mechanochromism and a 100 nm red-shift of fluorescent spectrum could be observed after grinding. The complex with a diphenylmethane bridge exhibited mechanochromism with a change in fluorescence from green to blue (25 nm red-shift after grinding). The ground complexes reverted to their original states by treatment with CH2Cl2. No mechanochromism was observed for either the biphenyl or diphenylethane containing complexes.

The diisocyano-based bimetallic gold (I) complexes displayed mechanochromic properties, and the different organic bridge can affect their mechanochromism. Figure optionsDownload as PowerPoint slideHighlights
► The mechanochromic activity of diisocyano bridge gold (I) complexes are described.
► Crystal structures of diisocyano bridge gold (I) complexes are discussed.
► The nature of the bridging ligands upon the mechanochromic response are reported.