Synthetic routes for IQTPA, IQTPAflu small molecules
- 5-Bromoisatin (4.42 mmol) was dissolved in dimethylformamide(DMF) 12 ml, K2CO3 (5.3mmol) and 1-bromobutane (9.0mmol) were added. The solution was stirred at RT for 12h. After extraction with dichloromethane, dried over magnesium sulfate, and filtered. Solvents were removed under reduced pressure and the product was purified by column chromatography.
- 5-Bromo-1-butyl-2,3-dione (7.09mmol) was dissolved in acetic acid 40ml and o-phenylenediamine (9.22mmol) was added. The reaction mixture was stirred at 110ºC for 12 hours and extracted with ethyl acetate. Solvents were removed under reduced pressure and the crude residue was purified by column chromatography.
- The final indoloquinoxaline-based small molecules, in a Schlenk flask, 9-bromo-6-butyl-6H-indolo[2,3-b]quinoxaline (2.82mmol), (4-(diphenylamino)phenyl)-boronic acid (4.24mmol), and Pd(PPh3)4 (5% mol) were dissolved in toluene. After nitrogen bubbled for 15 min, an aqueous 2M solution of K2CO3 was added to the above solution. The mixture was heated to 90 °C and stirred for 2 days under an N2 atmosphere.
Figure. 1 (a) Synthetic routes for InQx-TPA and InQx-Flu (b) UV-vis absorption spectra of IQTPA and IQTPAFlu in film state, (c) Cyclic voltammograms of IQTPA and IQTPAFlu, (d) XPS Pb 4f spectra of perovskite films (e) TRPL decay curves.
Characterization
1H and 13C nuclear magnetic resonance (NMR) spectra were measured using a JEOL JNM ECP-400 spectrometer. X-ray diffractometry (XRD) was analyzed by using the Rigaku spectrometer (smart lab) with a Cu Kα source of wavelength 1.5406 Å at a range of 2θ = 10° to 2θ = 80°. UV−visible absorption spectra were carried by JASCO instruments and a Perkin Elmer UV7 Vis Lambda 365 Spectrometer. Ultraviolet photoelectron spectroscopy (UPS) was recorded on the Thermo Scientific Co. measurement. Field emission-scanning electron microscope (FE-SEM) images were measured using Hitachi (S-4800). Steady-state photoluminescence (PL) and a time-resolved photoluminescence (TRPL) were carried out by FlouTime 300 (PicoQuant Co.). Cyclic voltammetry (CV) measurements were analyzed by using VersaSTAT 3 Potentiometry (Princeton Applied Research) with 0.1 M tetrabutylammonium hexafluorophosphate (TBAP, Bu4NPF6) in anhydrous acetonitrile as the electrolyte. The glassy carbon electrodes coated with the IQTPA and IQTPAFlu, and Pt wire as working and counter electrodes, respectively. The silver wire, as the reference electrodes, with a ferrocene /ferrocenium (Fc/Fc+) external standard.