Interesting tid bit. Kateeva bought qdots from QM

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EXAMPLE 3: LIGAND EXCHANGE OF QUANTUM MATERIALS GREEN OPS WITH LIGAND EG4.3TSA

[00204] General: The solvents dimethoxy ethane (DME), ethyl acetate (EtOAc), hexanes and ethyl alcohol (EtOH) were purchased from Aldrich (anhydrous grade) and used without further purification in a glovebox. The ligand EG4.3TSA was synthesized as described in Example 1. The diluent, M-600-MI, was synthesized as described in Example 5. The QDs were purchased from Quantum Materials Corp in San Marcos, TX. An Amicon Ultra 4 (i.e. 4 mL volume) with high flux polyethersulfone (PES) membrane with 30K molecular weight cut off (MWCO) was used for centrifugal filtration. FTIR analysis was obtained on a Nicolet 6700 spectrometer equipped with a Smart iTR Attenuated Total Reflectance (ATR) Sampling Accessory. Analysis for optical density (OD) was performed on a Cary 5000 UV-Vis Spectrometer by Varian. [00205] Procedure: To six, 8 mL vials (synthesis performed in parallel) in the glovebox were added EG4.3TSA ligand (200 mg, 0.502 mmoles, 1.4 eq ligand / surface Zn atom (as shown in the table below) and DME (2.0 mL), and the reaction solution was gently swirled until clear. A flea size magnetic stir bar then was added, followed by a solution of green QDs in toluene (2.0 mL with [QD] of 10 OD450 measured at 450 nm). After closing the vial with a screw cap, the mixture was then heated in a thermostat-controlled heat block at 90 °C for 16 h. The reaction solution was clear green upon combination, and was also clear green after being heated overnight at 90 °C. The vial cap was replaced with a septum cap, and the volatiles were removed with flowing nitrogen gas using two syringe needles (nitrogen in and nitrogen out) to produce a clear, concentrated oil. The oil was dissolved in EtOAc (200 µ?) completely to form a clear solution, and the product was precipitated with hexanes (2.0 mL). After the addition of hexane, the vial was shaken aggressively for about 60 seconds and then centrifuged using an angular velocity, co, of 2000 for 10 minutes to produce a clear, intensely green pellet underneath a clear, colorless liquid supernatant. In the glove box the supernatant was removed and discarded before the dissolution / precipitation process was repeated again with EtOAc 200 µ?, precipitated with 2 mL of hexanes, mixed by shaking, centrifuged, and the supernatant removed to produce an intensely green pellet that was a little smaller in volume and a little thicker in viscosity than produced by the first precipitation. The product in each vial was dissolved in EtOH (1.0 mL) to a produce clear, green solution. At the same time, one Amicon Ultra 4 filter was cleaned with EtOH (4 mL) and centrifuged for 10 min to remove surfactant from the filter membrane. The solution from four vials then was added to the MWCO centrifuge filters, and the centrifuge filters were spun at an angular velocity, co, of 2000 until about 300 of solution remained above the filter element. During centrifugation, a small amount of green QDs leaked through the filter, but the vast majority were retained. The retained QDs had been concentrated into a yellow orange oil that could be observed by the eye above the MWCO filter element. The last two vials then were added to the filter, and the solution above the filter was mixed by 'pumping' the solution with a Pasteur pipette. The filter was spun on the centrifuge until about 500 µ?, of solution remained above the filter element. Each vial then was rinsed with EtOH, 1 mL, and that solution was added to the filter sequentially and the vials were spun on the centrifuge with enough EtOH so that each vial was rinsed with 2 x 1.0 mL EtOH. When the volume in the centrifuge filter was about 500 µ?, the solution was transferred to a tared vial and the volatiles were removed with flowing nitrogen gas to leave a concentrated paste of quantum dot concentrate or 'QD concentrate.' The vial was sent into the glove box and the product was placed under vacuum in the antechamber for 1 minute before weighing. The product was an intensely green grease that weighed 94.4 mg. It was easily dissolved in 1.0 mL EtOH, and a 20 sample was dissolved in 4.0 mL EtOH for an optical density (OD) measurement at 450 nm using a cuvette with 10 mm path length. Using the optical density from this dilute solution measurement the OD450 was projected back to the QD concentrate. The OD450 was 0.521, which made the EtOH solution 105 OD450 and the QD concentrate 1214 OD450. While dissolved in 1 mL of EtOH, 100 mg of M-600-MI then was added, and the volatiles were removed with flowing nitrogen gas followed by vacuum to leave a thick, intensely green, but flowing oil. The table below summarizes some of the numbers used in this synthesis.

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EXAMPLE 4: LIGAND EXCHANGE OF QUANTUM MATERIALS RED QDS WITH LIGAND EG4.3TSA

[00206] General: The solvents dimethoxy ethane (DME), ethyl acetate (EtOAc), hexanes and ethyl alcohol (EtOH) were purchased from Aldrich (anhydrous grade) and used without further purification in a glovebox. The ligand EG4.3TSA was synthesized as described in Example 1. The diluent, M-600-MI, was synthesized as described in Example 5. The QDs were purchased from Quantum Materials Corp in San Marcos, TX. An Amicon Ultra 4 (i.e. 4 mL volume) with high flux polyethersulfone (PES) membrane with 30K molecular weight cut off (MWCO) was also used for centrifugal filtration. FTIR analysis was obtained on a Nicolet 6700 spectrometer equipped with a Smart iTR Attenuated Total Reflectance (ATR) Sampling Accessory. Analysis for optical density (OD) was performed on a Cary 5000 UV- Vis Spectrometer by Varian.

[00207] Procedure: To six, 8 mL vials (synthesis performed in parallel) in the glovebox were added EG4.3TSA ligand (40 mg, 0.502 mmoles, 1.4 eq ligand / surface Zn atom, as shown in the table below) and DME (2.0 mL), and the reaction solution was gently swirled until clear. Then a flea size magnetic stir bar was added, followed by a solution of red QDs in toluene (2.0 mL with [QD] of 10 OD measured at 450 nm). After closing the vial with a screw cap, the mixture was then heated in a thermostat-controlled heat block at 90 °C for 16 h. The reaction solution was clear red upon combination and was also clear red after heating at 90 °C overnight. The vail cap was replaced with a septum cap, and the volatiles were removed with flowing nitrogen gas using two syringe needles (nitrogen in and nitrogen out) to produce a clear concentrated oil. The oil was dissolved in EtOAc (100 µ?) completely to form a clear solution, and the product was precipitated by the addition of hexanes

(2.0 mL). After hexane addition, the vial was shaken aggressively for about 60 seconds and then centrifuged using an angular velocity, co, of 2000 for 10 minutes to produce a clear, intensely red pellet underneath a clear, colorless liquid supernatant. In the glove box, the supernatant was removed and discarded before the dissolution / precipitation process was repeated with EtOAc 200 µ?, precipitated with hexanes 2 mL, mixed by shaking, centrifuged and the supernatant removed to produce an intensely red pellet that was a little smaller in volume and a little thicker in viscosity than produced by the first precipitation. The product in each vial was dissolved in EtOH (1.0 mL) to produce a clear, red solution. At the same time, one Amicon Ultra 4 filter was cleaned with EtOH (4 mL) and centrifuged for 10 min to remove surfactant from the filter membrane. The solution from four vials was then added to the MWCO centrifuge filters, and the centrifuge filters were spun at an angular velocity, co, of 2000 until about 300 of solution remained above the filter element. During centrifugation, a small amount of red QDs leaked through the filter, but the vast majority were retained. The retained QDs had been concentrated into a dark red oil that could be observed by the eye above the MWCO filter element. The last two vials then were added to the filter, and the solution above the filter was mixed by 'pumping' the solution with a Pasteur pipette. The filter was spun on the centrifuge until about 500 µ?, of solution remained above the filter element. Each vial then was rinsed with EtOH, 1 mL, that solution added to the filter sequentially, and the vials were spun on the centrifuge with enough EtOH so that each vial was rinsed with 2 x 1.0 mL EtOH. When the volume in the centrifuge filter was about 500 µ?, the solution was transferred to a tared vial and the volatiles were removed with flowing nitrogen gas to leave a concentrated paste of quantum dot concentrate or 'QD concentrate.' The vial was sent into the glove box, and the product was placed under vacuum in the antechamber for 1 minute before weighing. The product was an intensely red grease that weighed 17.3 mg. It was easily dissolved in 1.0 mL EtOH and a 20 µ?, sample was dissolved in 4.0 niL EtOH for an optical density (OD) measurement at 450 nm using a cuvette with 10 mm path length. Using the optical density from this dilute solution measurement, the OD450 was projected back to the QD concentrate. The OD450 was 0.310, which made the EtOH solution 62.3 OD450 and the QD concentrate 3664 OD450. While dissolved in 1 mL of EtOH, 200 mg of M-600-MI was then added, and the volatiles were removed with flowing nitrogen gas followed by vacuum to leave a thick, intensely red grease. The table below summarizes some of the numbers used in this synthesis.

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