K2co3

Filmtec XLE flat-sheet membranes were from OctoChem Inc. (Vandalia, IL, USA). Potassium pyrosulfate, 2-BiBB, 4-dimethylaminopyridine (4-DMAP), 2,2′-bipyridine (bpy), N-methylmorpholine (NMM), and FeCl₃ were used as received, and 2-HEMA was passed through a column of active neutral alumina to remove its inhibitor; all were from Tokyo Chemical Industry (Tokyo, Japan). Potassium persulfate, strontium chloride, and sodium nitrate were from Sigma-Aldrich (Rehovot, Israel) and used as received. Active neutral alumina, boric acid, N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammoniumbetaine (SBMA) (which was washed with diethyl ether and dried in vacuo before use), BaCl₂, sodium metasilicate, CaCl₂, and NaCl were from Merck KGaA (Darmstadt, Germany) and (except where noted) used as received. CuBr₂ and Na₂SO₄ were from Acros Organics (Geel, Belgium); sodium acetate, l-AscOH, MgCl₂, and NH₄Cl were from Carlo Erba Reagents (Barcelona, Spain); K₂CO₃, KCl, cyclohexane, and isopropanol were from DaeJung Chemicals (Siheung, Republic of Korea); all were used as received. NaHCO₃, NaOH, absolute methanol, acetonitrile (LC gradient grade), diethyl ether, and hydrochloric acid (37%) were obtained from BioLab (Jerusalem, Israel) in analytical reagent grade and used without further purification.