4‐Sulfobenzyl, a New Carboxy Protecting Group

“…Derivatives of PBI, produced by chemical grafting of sulfonated groups, have been described elsewhere 14, 17. Figure 1 shows the synthetic route used to prepare N ‐benzylsulfonate polybenzimidazole.…”

Section: Methodsmentioning

confidence: 99%

Methanol permeability and proton conductivity of polybenzimidazole and sulfonated polybenzimidazole

Liu

2004

Polymer International

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The preparation of sulfonated polybenzimidazole (sPBI) by the grafting of (4-bromomethyl) benzenesulfonate onto polybenzimidazole (PBI) has been investigated. The methanol permeability and proton conductivity of PBI and sPBI have been studied, and the effects of methanol concentration and temperature on the methanol permeability of PBI and sPBI membranes are discussed. The results showed that the PBI membrane is a good methanol barrier. Methanol permeability in this membrane decreases with increasing methanol concentration and increases with increasing temperature. The temperaturedependence of methanol permeability of PBI and sPBI membranes is of the 'Arrhenius type'. Methanol permeation of sPBI is less sensitive to temperature than that of PBI. However, sPBI is a poorer methanol barrier when compared to PBI. Methanol permeability in sPBI membranes increases with increasing methanol concentration and temperature. The proton conductivity of sPBI is 4.69 × 10 −4 S cm −1 at room temperature in the hydrated state. The DC conductivity of sPBI-H 3 PO 4 increases with increasing temperature. Proton transport in sPBI-H 3 PO 4 is less sensitive to temperature than that in PBI-H 3 PO 4 .

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“…Compound 2 was prepared by literature methods. 1 All other starting materials are commercially available and used as received without further purification. All NMR spectra were recorded at room temperature using a Varian Mercury 300 spectrometer.…”

mentioning

confidence: 99%

Selective Oxidation of sp³ C−H Bonds in Water Catalyzed by a Glycinate−Platinum(II) Complex

2009

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General Information: All air and/or moisture sensitive compounds were manipulated by using standard high-vacuum line, Schlenk, or cannula techniques, or in a glove box under a nitrogen atmosphere. Compound 2 was prepared by literature methods. 1 All other starting materials are commercially available and used as received without further purification. All NMR spectra were recorded at room temperature using a Varian Mercury 300 spectrometer. Synthesis of Compound 5:K[Pt II (glycine)Cl 2 ] was synthesized by using a modified literature procedure. 2-4 K 2 Pt II Cl 4 (1g, 2.4 mmol) and glycine (0.18g, 2.4 mmol) were added to a round bottom flask. Water (25 mL) was added, and the reaction mixture was heated to 100 °C using an oil bath. After heating for 10 minutes, 1 equivalent of KOH (0.135g in 20 mL water) was added dropwise to the reaction mixture. The color of the solution turned from red to yellow. The solvent was removed under vacuum and pure K[Pt II (glycine)Cl 2 ] was recrystallized from a 9:1 ethanol:water mixture. Yield: 0.27g, 30%. Oxidation of Sodium p-Toluenesulfonate and Compound 2:Reactions were carried out on solutions of 0.013 M K 2 Pt II Cl 4 or K[Pt II (glycine)Cl 2 ], 0.11 M Na 2 Pt IV Cl 6 , and 0.155 M sodium p-toluenesulfonate in 3 mL of D 2 O. In a typical experiment, the reaction mixture was prepared in a 20 mL glass vial. A magnetic stir bar was then added and the vial was sealed using a Teflon screw cap. The vial was then heated to the desired temperature using an oil bath. Formation of products was monitored by following the growth of the corresponding 1 H NMR signals. Direct oxidation of 2 (prepared independently) to 3 was carried out using the same procedure. The starting materials and products are all known compounds. 5 References:(1) Hubbuck, A.; Bindewald, R.; Fohles, J.; Naithani, V. K.; Zahn, H.

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4‐Sulfobenzyl, a New Carboxy Protecting Group

Cited by 16 publications

References 9 publications

Structure–property relationships for a series of polyimide copolymers with sulfonated pendant groups

Structure–property relationships for a series of polyimide copolymers with sulfonated pendant groups

Methanol permeability and proton conductivity of polybenzimidazole and sulfonated polybenzimidazole

Selective Oxidation of sp³ C−H Bonds in Water Catalyzed by a Glycinate−Platinum(II) Complex

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4‐Sulfobenzyl, a New Carboxy Protecting Group

Cited by 16 publications

References 9 publications

Structure–property relationships for a series of polyimide copolymers with sulfonated pendant groups

Structure–property relationships for a series of polyimide copolymers with sulfonated pendant groups

Methanol permeability and proton conductivity of polybenzimidazole and sulfonated polybenzimidazole

Selective Oxidation of sp3 C−H Bonds in Water Catalyzed by a Glycinate−Platinum(II) Complex

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Selective Oxidation of sp³ C−H Bonds in Water Catalyzed by a Glycinate−Platinum(II) Complex