Short-RInChIKey=SA-FUHFF-UHFFFADPSC-VIRCVYOPUF-UHFFFADPSC-NUHFF-LGEIA-NUHFF-ZZZ

1,8-bis[(E)-2-(4-pyridyl)ethenyl]naphthalene (0.10 g, 0.30 mmol, 1.00 equiv.) and iodomethane (0.17 g, 1.20 mmol, 4.00 equiv.) were suspended in DMF (10 ml), the mixture was heated at 50°C for 16 hours. After cooling down, the precipitation was collected and washed with acetone several times. The solid was dissolved in water (500 ml) and AgCl (0.17 g, 1.20 mmol, 4.00 equiv.) was added, the mixture was stirred at 25 °C for 5 days. After filtration, the water was evaporated and the desired product 4,4'-((1E,1'E)-naphthalene-1,8-diylbis(ethene-2,1-diyl))bis(1-methylpyridin-1-ium) chloride was obtained as a light yellow powder (0.12 g, 0.28 mmol, 92%).