Sodium bipyridyl

Another factor that can influence the environmental distribution of a chemical is the presence of charged groups. Some pollutants, such as the sodium or potassium salts of phenoxyalkanoic herbicides, dinitrophenols, and tetra- or penta-chlo-rophenol, exist as anions in solution. Others, such as the bipyridyl herbicides diquat and paraquat, are present as cations. In either case, the ions may become bound to organic macromolecules or minerals of soils or sediments that bear the opposite... 

In the production of 4,4 -bipyridyl from pyridine, the reaction between pyridine and metallic. sodium in liquid ammonia is involved, followed by oxidation. By adopting a continuous reactor, the process has been made safer and yields have probably improved. For a hazardous chemical like diazomethane, even at a capacity of 60 tpa a continous plant has been adopted. 

The reductive coupling of allyl halides to 1,5-hexadiene at glassy C electrodes was catalyzed by tris(2, 2,-bipyridyl)cobalt(II) and tris(4,4 -dimethyl-2, 2/-bipyridyl)cobalt(II) in aqueous solutions of 0.1 M sodium dodecylsulfate (SDS) or 0.1 M cetyltrimethylammonium bromide (CTAB).48 An organocobalt(I) intermediate was observed by its separate voltammetric reduction peak in each system studied. This intermediate undergoes an internal redox reaction to form 1,5-hexadiene... 

Pyridine is converted to a slurry of a dihydrobipyridyl by treatment with sodium in liquid ammonia at —33°C, then warming to 10°C to evaporate excess ammonia. The slurry was then transferred to a decomposition vessel (for subsequent aerobic oxidation to liberate bipyridyl), the transfer pipe being flushed through with cold dimethoxyethane. When warm solvent was used for this purpose on one occasion, oxidation proceeded so fast that ignition occurred. 

From an analytical point of view, the use of anionic surfactants as enhancers of CL reactions is most limited. One of the most recent examples is the use of sodium dodecylbenzene sulfonate (SDBS) as a CL enhancer of the system Ru(hpy) - SO - KBr03 (bpy = 2,2 -bipyridyl) [60], The authors of this work propose the following mechanism for the chemiluminescent system ... 

Tetramethyl- or tetraphenyl- (cyclobutadiene)nickel dihalides undergo reductive ligand substitution with nitrogen donor ligands such as 2,2 -bipyridine or 1,4-diaza-1,3-dienes with the addition of sodium metal237. The 2,2/-bipyridyl ligand is readily displaced and reaction of this complex with a variety of olefins and alkynes leads to cycloaddition reactions with the cyclobutadiene ligand. 

The ENDOR technique refers to electron-nuclear double resonance. This consists of the effect on a partially saturated ESR line of simultaneously irradiating the sample with a radiofrequency to induce nuclear resonance transitions of hyperfine coupled nuclei. It may enable one to obtain information about signs of coupling constants. ELDOR is the technique corresponding to electron-electron double resonance. Such techniques, coupled with TRIPLE resonance, have been utilized and well described in a discussion of pyridine and 4,4-bipyridyl radical anion ESR spectra measured in sodium/liquid ammonia (80JMR<41)17). 

Mixed dinuclear complexes of tartrates and 2,2 -bipyridyl or 1,10-phenanthroline and chromium(III) have been prepared 934,935 the typical structure is illustrated below (213). Stereochemical correlations have been carried out by oxidatively cleaving the tartrate bridge (214,215).936 The crystal structure of sodium hydrogen bis(//-meso-tartrato)bis(2,2 -bipyridyl)dichromate(III) heptahydrate has been reported.937... 

Certain metals (e.g. Na, Zn) add one electron to pyridine to form a radical anion (373 - 374) which can dimerize by reaction at the a- or y-position these dimers form bipyridyls by hydride ion loss. On treatment with sodium at 20°C, pyridine forms mixtures of 2,2 -, 2,3 -, 2,4 - and 4,4 -bipyridyl, probably by aromatization of intermediate dihydro compounds (375 —> 376). The reaction can be directed to give largely 4,4 -bipyridyl, a product of commercial importance. 

Recently, evidence has been provided for the existence of polymeric [Agl2] ions in fairly concentrated solutions of sodium diiodoar-gentate(I) in acetonitrile (119). In bis(2,2-bipyridyl)copper(II) bis[dich-lorocuprate(I) ] (24), the polymeric anion is composed of pairs of edgesharing tetrahedra linked via linear Cl—Cu—Cl units (see Section II,A,2). 

Bipyridyl (20) (63AHC(2)179) is synthesized by oxidative dimerization of pyridine over hot Raney nickel, while 4,4 -bipyridyl (21) (B-79MI10705) is made by free radical coupling of the pyridine radical anion generated by sodium in liquid ammonia, followed by air oxidation (Scheme 6). Quaternization of (21) with methyl chloride gives paraquat while reaction of (20) with 1,2-dibromoethane gives diquat. 

Abbreviations DHG = Ar,Ar-di(2-hydroxyethyl)glycine NTA = nitrilotriacetic acid EDTA = ethylenediaminetetraacetic acid tiron = pyrocatechol-3,5-disulfonic acid BAL = 2,3-dimercaptopropanol unithiol = sodium 2,3-dimercaptopropane sulfonate tren — triaminatriethylamine penten = tetrakis(aminoethyl)ethylenediamine bipy = 2,2 -bipyridyl phen = 1,10-phenanthroline. 

Perfluoro-2,2 -bipyridyl (12) with sodium methoxide yields heptafluoro-4-methoxy-2,2 -bi-pyridyl and hexafluoro-4,4 -dimethoxy-2,2 -bipyridyl.124... 

Other aqueous preparative methods include aerial oxidation of an alkaline solution of CoS04 and NaCNO to give the fulminatocobaltate(III) anion [Co(CNO)6]3-, reduction of ruthenate(VI) by excess of fulminate to give [Ru(CNO)6]4, and displacement of 2,2 -bipyridyl or 1,10-phenan-throline from nickel(II) or cobalt(III) complexes to give [Ni(CNO)4]2 or [Co(CNO)6]3. Liquid ammonia may replace water as solvent [Ni(NH3) ]2+ and [Co(NH3)6]3+, for example, react with sodium fulminate in this solvent to form [Ni(CNO)4]2 and [Co(CNO)6]3. In all these reactions fulminate behaves very like cyanide with [AuClJ-, however, reduction to form the gold(I) complex [Au(CNO)2] takes place and no gold(III) complex can be isolated. 

In the presence of excess bipyridyl, ruthenium trichloride is an effective catalyst for the selective epoxidation of alkenes by sodium periodate (equation 297). The epoxidation is syn and stereospecific for cis and trans alkenes.637... 

Chromic acid oxidation of D-sorbitol and D-mannitol has been studied in the presence and absence of 2,2/-bipyridyl (bipy). A monomeric species of Cr(VI) has been found to be kinetically active in absence of bipy, whereas in the catalysed path the Cr(VI)-bipy complex has been found to be the active oxidant. Sodium dodecyl sulfate... 

Herbicides are chemicals used to destroy unwanted plants (terrestrial or aquatic) called weeds. Herbicides fall into two broad categories inorganic (e.g., copper sulfate, sodium chlorate, and sodium arsenite) and organic (e.g., chlorophenoxy compounds, dinitrophenols, bipyridyl compounds, carbamates, and amide herbicides). Historically, inorganic compounds were the first available and the first used. There has been over a long period a continuous effort to develop herbicide compounds that are more selective—that affect weeds, as opposed to desirable plants. 

Analogously, hexafluoro-l,8-diazabiphenylene (34) with methanolic sodium methoxide yields the 3,3 -bipyridyls (35) and (36) <90JCR(M)1301>. 

The importance of the stereochemistry of solutes is shown in the solubility data for bipyridyls and biphenyl (Bennetto and Letcher, 1972). It is also confirmed by the discovery that the transfer of sodium chloride to dilute solutions of mannitol is endothermic whereas the transfer to solutions of sorbitol is exothermic (Stem and O Connor, 1972). 

Ethyl 2-butyrylacetate. In a 1-L, three-necked, round-bottomed flask fitted with a mechanical stirrer, dry nitrogen inlet, and thermometer is placed 19.8 g (0.150 mol) of monoethyl malonate (Note 1), 350 mL of dry tetrahydrofuran (THF, Note 2), and 5 mg of 2,2 -bipyridyl. The solution is cooled to approximately -70°C (in an isopropyl alcohol-dry ice bath) and a 1.6M solution of n-butyllithium in hexane is added from a dropping funnel while the temperature is allowed to rise to approximately — 10°C. Sufficient n-butyllithium is added (approx. 190 mL) until a pink color persists for several minutes (Note 3). The heterogeneous solution is recooled to -65°C and 7.90 mL (7.98 g, 75 mmol) of iso-butyryl chloride (Note 4) is added dropwise over 5 min. The reaction solution is stirred for another 5 min (Note 5) and then poured into a separatory funnel containing 500 mL of ether and 300 mL of cold, 1 N hydrochloric acid (Note 6). The funnel is shaken, the layers are separated, and the organic phase is washed with two 150-mL portions of saturated aqueous sodium bicarbonate, followed by 150 mL of water, and dried over anhydrous sodium sulfate. Removal of the solvents under reduced pressure leaves 11.70 g (98%) of ethyl 2-butyrylacetate (Note 7). The crude product can be distilled at 70-74°C (7 mm) (80% yield, 96% purity by GLC). 

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