Starting materials: AEQT.2HBr, PbBr2, ethylene glycol, HBr (aq)
Product: (AEQT)PbBr4 crystals
Description: Prepare the starting AEQT.2HBr salt using a technique similar to that described in detail for the synthesis of AMQT.2HCl [1]. Grow (AEQT)PbBr4 crystals from a slowly cooled, saturated, aqueous solution containing the organic and inorganic salts. First, weigh 14.5 mg (0.025 mmol) of AEQT.2HBr and 18.3 mg (0.050 mmol) of PbBr2 and add to a test tube under an inert atmosphere. Dissolve the contents in the sealed tube at 120 °C in a solvent mixture of 22 mL of deionized water, 1 mL of ethylene glycol, and 2 drops of 48% aqueous HBr, forming a nominally saturated yellow solution. Slow cool at 2 °C/h to 0 °C, to form small, yellow, sheetlike crystals of the desired (AEQT)PbBr4 compound. To prevent deforming the thin crystals, remove the product from the reaction tube using a pipet and deposit on filter paper to absorb the solution.
Comment: References: [1] (a) Muguruma, H.; Saito, T.; Sasaki, S.; Hotta, S.; Karube, I. J. Heterocycl. Chem. 1996, 33, 173. (b) Muguruma, H.; Saito, T.; Hiratsuka, A.; Karube, I.; Hotta, S. Langmuir 1996, 12, 5451.
Method: Temperature-dependent photoluminescence
Description: Photoluminescence spectra were recorded using a Spex Fluorolog-2 spectrofluorometer. 360 nm light from a xenon arc lamp was used as the excitation source, after being passed through a SPEX 1680 0.22 m double monochromator. The emission was passed through a similar monochromator and detected with a SPEX 1911F photomultiplier tube (PMT). Crystals of the material were pressed between two sapphire windows. The deposit on sapphire was then mounted on a coldfinger. The temperature was maintained using an APD Cryogenics displex system.
Comment: Refer to Figure 10.
Starting materials: (AEQT)PbBr4, quartz, acetone, ethanol
Product: (AEQT)PbBr4 thin film. Film thickness between 500 Å and 900 Å.
Description: To prepare (AEQT)PbBr4, sonicate quartz samples in 2% (w/v) detergent solution in water (20 min), then sonicate in acetone (20 min) and ethanol (20 min). Boil in ethanol (5 min) and place in a 130 °C oven to dry. Add 0.003 g of (AEQT)PbBr4 compounds to 0.1 mL of methanol, and sonicate again for 10 min. Place the charge dropwise via a syringe on the tantalum heater of the SSTA chamber. Close chamber and evacuate all solvent with a rotary mechanical pump. Switch on a turbomolecular pump, and pump system to approximately 10^{-7} Torr. To initiate the evaporation, pass a large current of approximately 65 A through the heater for about 4 s. Anneal the (AEQT)PbBr4 films at 180 °C for 15 min.
Comment: Single source thermal ablation (SSTA) technique.
Method: Photoluminescence
Description: Photoluminescence spectrum was recorded at room temperature using a Spex Fluorolog-2 spectrofluorometer. 370 nm light from a xenon arc lamp was used as the excitation source, after being passed through a SPEX 1680 0.22 m double monochromator. The emission was passed through a similar monochromator and detected with a SPEX 1911F photomultiplier tube (PMT).