Novel diisocyano-based dinuclear gold(I) complexes with aggregation-induced emission and mechanochromism characteristics

• A series of novel constitutional isomers containing dinuclear gold(I) units have been synthesized.
• These diisocyano-based dinuclear gold(I) complexes 1-3 all exhibit excellent AIE property.
• Ortho-isomer luminogen 1 shows switchable mechanochromic behavior.
• Meta-isomer luminogen 2 exhibits reversible mechanical force-induced luminescence enhancement effect.
• No mechanochromism phenomenon is found for para-isomer luminogen 3.

A series of constitutional isomers containing dinuclear gold(I) units were designed, synthesized and characterized using IR spectrometry, NMR spectroscopy and elemental analysis. The aggregation-induced emission (AIE) characteristics of the complexes were investigated by photoluminescence (PL) and UV/Vis spectroscopy. The results indicated that gold(I) complexes 1-3 exhibited significant AIE phenomena. PL spectroscopy, used to probe their solid-state mechanochromic properties, suggested ortho-isomer luminogen 1 exhibited reversible mechanochromic fluorescence, whereas meta-isomer luminogen 2 showed switchable mechanical force-induced luminescence enhancement behavior. No mechanochromism behavior was observed for para-isomer luminogen 3. Powder X-ray diffraction indicated that the morphology phase conversion between crystalline and amorphous states is responsible for the mechanochromism or mechanical force-induced emission enhancement characteristics.

Constitutional isomers containing gold(I) units all exhibit significant AIE property. Ortho-isomer exhibits reversible mechanochromic fluorescence. Meta-isomer shows switchable mechanical force-induced luminescence enhancement behavior. Para-isomer exhibits no mechanochromism behavior.Figure optionsDownload as PowerPoint slide