Synthesis of novel phenylenevinylene linkers with electron-donating substituents by the Heck reaction

• Synthesis of three OPV systems with carboxylic acid at the opposite ends of their structure.
• Very high reaction yields obtained by a modification of Heck methodology.
• Electron-donating groups have strong effects in the luminescent properties of OPVs.
• Acid OPVs can be used as linkers to build luminescent MOFs for chemosensory applications.

Three new carboxylic-acid substituted oligo-phenylenevinylenes (OPVs) with electron-donating substituents in the central ring were synthesized in high yield by the Mizoroki–Heck reaction. The linkers were optically characterized by UV–vis absorption spectrophotometry, fluorescence spectroscopy in solution and the solid state, and measurement of the emission quantum yield. A comparison of substituted and unsubstituted OPVs shows that the electron-donating groups significantly affect the luminescent properties of the linkers. As the electron-donating strength of the substituent increases, the absorption bands strengthen, the emission wavelength shifts bathochromically, and the emission quantum yield increases. Moreover, fluorescence analysis of the OPVs in the solid state shows that the nature of the substituent significantly affects the inter-chromophore interactions. These results suggest that the new linkers have potential for electro-optic applications in which high emission efficiency is required, such as chemical sensing.