Tmpda

Synthesis of N,N,N′,N′–Tetramethylpropylenediamine N–oxide (CC1) and N,N,N′,N′–tetramethyl–ethane–1,2–diamine N–oxide (CC2) was carried out by oxidation of N,N,N′,N′–Tetramethyl–1,3–propanediamine (TMPDA) and tetramethylethylenediamine (TEMED) respectively according to Cope and Ciganek [39] with a few modifications. Briefly, 0.35 mole of TMPDA or TEMED (Sigma–Aldrich), 0.7 mole of hydrogen peroxide (Sigma–Aldrich) and 45 ml of methanol (Bio–Lab Ltd.) were placed in a flask. The solution was allowed to stand at room temperature for 36 hours. Portions of 0.7 mole hydrogen peroxide were added after 2 and 4 hours. Formation of the product was confirmed by NMR and mass spectrometry.

Two sorts of porous silica, different by their morphological characteristics were purchased from the Daiso Co. (Nishi-Ku, Osaka, Japan). Dimethylsulfoxide (DMSO), tetrahydrofuran (THF), TEMED, and TMPDA, purchased from Sigma-Aldrich Chemie (GmbH, Germany), were used as received. DEHEA, from Fluka Chemical Co. (Buchs, Switzerland), was used after distillation under reduced pressure. 2,2’-Azo-bis(isobutyronitrile) (AIBN), from Sigma-Aldrich, was purified by recrystallization three times from methanol. Potassium dichromate analytical grade and 1,5-diphenylcarbazide, purchased from Sigma-Aldrich Chemie (GmbH, Germany), were used as received. Vinylbenzyl chloride (VBC), purchased from Sigma-Aldrich, was used after distillation under reduced pressure (about 4 mm Hg), being kept at +4 °C. The synthesis of PVBC was performed by free radical polymerization of VBC with AIBN as initiator, at a concentration of 1.12 g/100 g VBC. The separation and characterization of PVBC have been presented in detail, elsewhere [47 (link)]. The PVBC used in this work had: M_w = 31,900 g/mol and M_w/M_n = 1.74.

Activated carbon (YP-50F) was purchased from Kuraray Chemical Co. (Tokyo, Japan). Matrimid^® 5218 polymer was purchased from Huntsman Corporation (Conroe, TX, USA). TMPDA, ODPA, acetic anhydride (Ac₂O), graphene oxide (GO, 15–20 sheets, 4–10% edge-oxidized) and triethylamine (TEA) were purchased from Sigma Aldrich (St. Louis, MO, USA). Chloroform and N,N-dimethylacetamide (DMAc) were purchased from VWR. Distilled water was synthesized in-house. All chemicals and reagents mentioned above were used as received without additional purifications.