Quaternary salts bipyridine

Quaternary Salts. Herbicides paraquat (20) and diquat (59) are the quaternary salts of 4,4 -bipyridine (19) and 2,2 -bipyridine with methyl chloride and 1,2-dibromoethane, respectively. Higher alkylpyridinium salts are used in the textile industry as dye ancillaries and spin bath additives. The higher alkylpyridinium salt, hexadecylpytidinium chloride [123-03-5] (67) (cetylpyridinium chloride) is a topical antiseptic. Amprolium (62), a quaternary salt of a-picohne (2), is a coccidiostat. Bisaryl salts of butylpyridinium bromide (or its lower 1-alkyl homologues) with aluminum chloride have been used as battery electrolytes (84), in aluminum electroplating baths (85), as Friedel-Crafts catalysts (86), and for the formylation of toluene by carbon monoxide (87) (see QuaternaryAA ONiUM compounds). 

Quaternary salts of 4,4 -bipyridine other than 1-alkyl or 1-aryl quaternary salts have also been synthesized. Thus l,l -dialkoxy diquaternary salts are formed by reaction of 4,4 -bipyridine l,l -dioxide (see next section) with dialkyl sulfates," and 1-alkyl-I -alkoxy diquaternary salts are obtained similarly. l,r-Bis(2,4-dinitrophenoxy)-4,4 -bipyridinium bisffluoro-borate) has been prepared from 4,4 -bipyridine l,l -dioxide by reaction with 2,4-dinitrobenzenediazonium fluoroborate in sulfolane. Interestingly,... 

A number of other routes are available for the syntheses of diquaternary salts of 4,4 -bipyridines. One method that has been extensively studied involves reaction of a 1-alkylpyridinium salt with sodium amalgam (or sodium in liquid ammonia) to form the 1,1 -dialkyl-1,1, 4,4 -tetrahydro-bipyridine, which is readily oxidized to the corresponding l,l -dialkyl diquaternary salt. This reaction is analogous to the synthesis of 4,4 -bipyridine by the action of sodium on pyridine, followed by oxidation of the intermediate tetrahydrobipyridine. " The reduction may be achieved electrolytically or by reaction with zinc or magnesium. Various oxidizing agents have been used to assist the conversion to the di-quaternary Another synthesis of diquaternary salts of... 

Bilirubin and bilirubin oxidase were used for cathodic oxygen reduction, while Ru(bpy)3 " /Ru(bpy)3 [Ru(bpy)3 + and Ru(bpy)3 are complex tris (bipyridine)ruthenium(III) and tris(bipyridine)ruthenium(II) cations] was the mediator redox system. In the electrodes, these enzymes were immobilized with Nafion solution treated with quaternary ammonium salts, and put on a support of carbonized cloth, serving as the current collector. The treated Nafion solution helped to maintain enzyme activity for a long time. 

ATRP was also combined with other polymerization methods in the preparation of polymer clay nanocomposites. Yang and coworkers reported the preparation of poly(L-lactide) (PLLA) comb polymer brushes on the surface of sihcate layers by using a combination of in-situ ATRP and ROP (Figure 10.7) [34]. An ATRP initiator with a quaternary ammonium salt end group was intercalated into the interlayer spacing of clay layers via ion exchange. In-situ ATRP of hydroxyethyl methacrylate (HEMA) in the presence of CuBr and bipyridine afforded the PHEMA backbone. PLLA comb polymers were grown from the PHEMA backbone by ROP. Because... 

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