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Park, Yoonsu, et al. International Journal of Hydrogen Energy 45.57 (2020): 32780-32788.
Iron phosphide (FeP) has garnered significant attention as a hydrogen evolution reaction (HER) catalyst due to its cost-effectiveness, high catalytic activity, and stability across a wide pH range. However, a systematic analysis of FeP nanoparticles (NPs) is still required to enhance their catalytic performance. Herein, we report the synthesis of FeP NPs through phosphidation reactions using various phosphorous sources (TOP, trioctylphosphine; TPP, triphenylphosphite; TEAP, tri(diethylamino)phosphine; and TBP, tri-n-butylphosphine).
Synthesis of FeP Nanoparticles
For the phosphidation of iron NPs, 7 mL of squalane and 3 mL of the phosphorous source (TOP, TPP, TEAP, or TBP) were added to a 50 mL three-neck flask. The solution was degassed at 120 °C for 1 hour to remove impurities. Subsequently, it was heated to 360 °C and maintained at this temperature for 1 hour to activate the phosphidation process. At 360 °C, the solutions containing TPP and TEAP turned opaque brown, while those containing TOP and TBP remained clear light yellow. After the activation process, 10 mL of ODE/OLA solution containing Fe NPs was quickly injected into the phosphorous solution, and the temperature was then lowered to 300 °C and maintained. During the phosphidation reaction, NP samples were collected at intervals of 30 minutes, 1.5 hours, 3 hours, and 4 hours using a glass syringe for subsequent electrochemical and material analyses. All samples were washed by adding ethanol/chloroform and centrifuged at 6000 rpm for 5 minutes. This washing process was repeated three times. All NP samples were stored in chloroform.
Mondal, Mukulesh, et al. The Journal of Organic Chemistry 80.11 (2015): 5789-5794.
A catalytic protocol is described for the diastereoselective synthesis of β-lactones possessing two stereocenters from disubstituted enones and α-chiral oxo-aldehydes. In the formation of β-lactones, tri-n-butylphosphine (PBu3) was found to be the optimal catalyst as it provided both good yields and diastereoselectivity.
β-Lactone Synthesis Procedure A: Under a nitrogen atmosphere at -78 °C, a solution of aldehyde (1 equivalent) and phosphine catalyst (PBu3 in most cases) (0.1 equivalent) in THF (with specified amounts for each instance) is added dropwise to a solution of enone (3 equivalents) in THF (with specified amounts for each instance). The reaction mixture is stirred at -78 °C for 8 hours. The reaction mixture is then gradually warmed to room temperature over 12 hours in a cooling bath (total reaction time = 20 hours). The crude solution is passed through a plug (Iatrobeads, 2.5 cm × 3.0 cm, 6 g) [approximately 50 times the estimated weight of the product mixture]. The plug is eluted with 10% EtOAc/hexane solvent system (250 mL), and the solvent is removed under vacuum, providing the desired β-lactone 3 in most cases in high purity (≥95%).
β-Lactone Synthesis Method B: Under a nitrogen atmosphere at -78°C, a solution of aldehyde (1 equivalent) and phosphine catalyst (PBu3 in most cases) (0.1 equivalent) in dichloromethane (with specified amounts for each instance) is stirred while a solution of enone (1 equivalent) in dichloromethane (with specified amounts for each instance) is added dropwise over 4 hours. The reaction mixture is stirred at -78°C for an additional 4 hours. The reaction mixture is then gradually warmed to room temperature over 12 hours in a cooling bath (total reaction time = 20 hours). Purification is performed as in Method A.
Han, Guangda, Yuanyuan Ju, and Hanying Zhao. Polymer Chemistry 7.5 (2016): 1197-1206.
Nanocapsules composed of crosslinked membranes and voids have been widely used as drug delivery carriers, sensors, and nanoreactors. In this study, a novel method for creating functional nanocapsules is introduced. A brush-like polymer, poly(oligoethylene glycol monomethyl ether methacrylate)-block-(poly(tert-butyl methacrylate)-graft-poly(2-(dimethylamino)ethyl methacrylate)) (POEGMA-b-(PtBMA-g-PDMAEMA)), was synthesized via a two-step reversible addition-fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP). The PDMAEMA chains were grafted onto the backbone through disulfide bonds. After crosslinking the PDMAEMA chains and cleaving the disulfide bonds using tri-n-butylphosphine (Bu3P), hydrophilic nanocapsules were obtained.
Preparation of PDMAEMA Nanocapsules
First, 7.5 mg of zinc acetate dihydrate was dissolved in 1 mL of water. Then, 0.1 mL of the salt solution was added to 1 mL of the micelle solution (5.0 mg mL-1), maintaining a molar ratio of zinc ions to DMAEMA units at 1:4. After stirring for 2 hours, the micelle solution was dialyzed into water. After removing water on a rotary evaporator, the crosslinked micelles were redispersed in toluene. To prepare the hydrophilic nanocapsules, the micelles were further crosslinked with DIB (divinylbenzene). DIB (0.0136 mmol) was dissolved in 0.1 mL of toluene and added to the micelle solution, which was stirred in the dark for 24 hours.
Next, a Bu3P solution (0.3 mL, 10% in hexane) was added to the micelle solution to cleave the disulfide bonds. After the cleavage reaction was complete, the solvent was removed using a rotary evaporator. Upon adding water, the hydrophilic PDMAEMA nanocapsules transferred to the aqueous phase, while POEGMA-b-PtBA remained at the bottom of the flask.
