Cationic rhenium(I) complexes bearing a π-accepting pyridoannulated N-heterocyclic carbene ligand: Synthesis, photophysical, electrochemical and theoretical investigation

Bright V‐Shaped bis‐Imidazo[1,2‐a]pyridine Fluorophores with Near‐UV to Deep‐Blue Emission

“…[27][28] Silica gel for column chromatography was purchased from Sigma-Aldrich. 1 H, 13 C{ 1 H} and 19 F{ 1 H} NMR spectra were recorded at 298 K on either Bruker AV500 spectrometer in deuterated solvents and the residual solvent peak was used as the internal reference. NMR spectra were calibrated to residual solvent signals.…”

“…The overall synthetic strategy employed for the preparation of the target compounds 4 b-f and 5 b-f is depicted in Scheme 1. For all the intermediates and target compounds, 1 H, 13 C and (when applicable) 19 F NMR spectra are available in Figure S1 was tested as well, namely pathway B in Scheme 1. This second strategy involves Suzuki-Miyaura cross-coupling between boronic acids and bromo-derivatives (either 4 a or 5 a).…”

“…1 H NMR (CDCl 3 , 500 MHz): δ 8.28 (d, J = 2 Hz, 1H), 7.66 (dd, J 1 = 2 Hz, J 2 = 8.5 Hz, 1H), 7.41 (d, J = 8.5 Hz, 2H), 7.27 (t, J = 8.5 Hz, 4H), 7.11-7.05 (m, 6H), 7.03 (t, J = 8.5 Hz, 2H), 6.57 (d, J = 8.5 Hz, 1H). 13…”

“…1 H NMR (CDCl 3 , 500 MHz): δ 8.24 (d, J = 2.5 Hz, 1H), 7.62 (dd, J 1 = 2.5 Hz, J 2 = 8.5 Hz, 1H), 7.4 (dt, J 1 = 2.5 Hz, J 2 = 8.5 Hz, 2H), 6.95 (dt, J 1 = 2.5 Hz, J 2 = 8.5 Hz, 2H), 6.55 (d, J = 8.5 Hz, 1H), 4.52 (s, 2H), 3.82 (s, 3H). 13…”

“…Imidazo[1,5‐ a ]pyridines and their coordination compounds are one of the most investigated ImPy isomers with optical properties [6–15] . Instead, design and investigation of luminophores containing the parental imidazo[1,2‐ a ]pyridine derivatives have been limited to date.…”