Ethylenediamine, as solvent

Basic solvents A basic solvent can be used to enhance the acidic properties of weak acids. To take full advantage of a basic solvent requires a strongly basic titrant. Moss, Elliott, and Hall were able to observe separate end points for carboxylic acids and phenols using sodium aminoethoxide as titrant in ethylenediamine as solvent. 

Reggel et al. observed that N-lithioethylenediamine in excess ethylenediamine as solvent rapidly isomerizes terminal alkenes to internal alkenes. Thus 1-octene on being refluxed with the reagent for 2 hrs. affords 90% of internal alkenes, mainly 2-octene. More striking is dehydrogenation, effected under very mild conditions. On addition of 4-vinylcyclohexene (1) to a solution of N-lithioethylenediamine... 

A modification of the preceding preparation employs ethylenediamine as a convenient nonvolatile solvent and Tetralin as the commercially available starting material. The results of the reduction are essentially identical. 

However, a weak inorganic acid e.g., boric acid, can be estimated conveniently employing ethylenediamine as the non-aqueous solvent. 

The reduction of an isolated carbon-carbon double bond by other methods is exceptional. Occasionally an isolated double bond has been reduced elec-Irolylicolly 344 and by dissolving melols. Sodium under special conditions -using tert-butyl alcohol and hexamethylphosphoramide as solvents - reduces alkenes and cycloalkenes in 40-100% yields [345. 3-Methylenecholestane, for example, afforded 3-methylcholestane in 74% yield on heating for 2 hours at 55-57° with lithium in ethylenediamine [346]. 

Ethylenediamine, as such, is used as a solvent for various compds, as a corrosion inhibitor in antifreeze soln, stabilizer in rubber latex, etc. Its use as a colorimetric reagent for expls, such as TNT, etc, is discussed in Vol 3 of Encycl, p C406 L Refs 1) Beil 4, 230, (398), [676] 1478 ... 

The Cr2+(aq) ion reacts readily with alkyl halides, apparently by a radical mechanism, to generate [R—Cr(H20)3]2+ ions the R—Cr bonds can then be cleaved by H30+. On the basis of these fundamental processes, Cr2+(aq) finds important use as a reductant for organic compounds, especially in aqueous DMF as solvent, with ethylenediamine present to complex the Crra produced. 

The product from Step 1(10.45 mmol) was dissolved in 75 ml methyl alcohol and added dropwise over 2 hours to a stirred solution of ethylenediamine (7.41 mol) dissolved in 50 ml methyl alcohol. The reaction stirred at ambient temperature and excess ethylenediamine and solvent removed. The residue was dissolved in 90 ml methyl alcohol and purified from residual ethylenediamine by reverse osmosis (Filmtec TC-30 membrane and AmiconTClR channel separator, methyl alcohol as solvent). After 48 hours no ethylenediamine could be detected by gas chromatography (Column, Tenax 60/80) and the product isolated in 6.72 g as a glassy solid. 

N-Alkyl- and N,N-dialkyl-ethylenediamines are prepared in a single step (cf. methods 427, 435, and 452) by the addition of gaseous ethylenimine to primary or secondary amines in the presence of anhydrous aluminum chloride (77-89%). Primary amines react at about 90° with benzene as solvent, whereas secondary amines react at 180° with tetralin or biphenyl as solvent. In a similar manner, homologs of ethylenimine and ammonia (or amines) react in high-pressure equipment at 100° in the presence of ammonium chloride. "... 

Se, and ethylenediamine, with T = 90 °C, t = 4 h. The particles are spherical and quite monodisperse. Qian and coworkers have also reported [70] a solvothermal preparation of CuInSe2, obtaining 15 nm particles from CuCh, InCh and Se in either ethylenediamine or diethylamine, at 180 °C for 15 h in ethylenediamine, and 36 h for diethylamine. CuInSe2 S [71] also has been prepared by Qian and coworkers using InCl3, CuCl2, S and Se with ethylenediamine as the solvent. 

Butadiyne has also been alkylated through the lithium alkynide. Thus, Holmes and Jones treated bis(trimethylsilyl)buta-l,3-diyne with MeLi in the presence of lithium bromide and obtained the monolithium alkynide, which was then alkylated in HMPA (Scheme 30). If the lithium alkynide was complexed with ethylenediamine then DMSO could be used as solvent. In addition, Himbert and Feustel prepared the lithium derivative of l-A A(-dialkylbuta-l,3-diyne by treatment of 4- -dialkyl-l,l,2-trichlorobut-l-en-3-yne with butyllithium. The lithium salt was not isolated but was alkylated to the l-alkyl-4-lV-di-alkylbuta-l,3-diyne (Scheme 31). 

By this method, 1-bromonaphthalene affords 1-naphthonitrile in 94% yield after refluxing for 4 hrs. with pyridine as solvent the reaction mixture is heated in an oil bath at 215-225° for 15 hrs., and the yield is 82-90%. Efficient procedures for liberating the nitrile from the cuprous halide complex involve pouring the brown reaction mixture into an aqueous solution of ferric chloride (oxidizes Cu+ to Cu ", which forms no complex), ethylenediamine (forms complexes with Cu+ and Cu " ), or sodium cyanide (forms soluble sodium cuprocyanide). The higher-boiling N-methyl-2-pyrrolidone (b.p, 202°) is also satisfactory, but is more expensive. 

A chain-shape polyamine and ethylene glycol system favors the formation of layered aluminophosphates with an Al/P ratio of 3/4. For instance, ethylenediamine, diethylenetriamine, and triethylenetetramine combining with ethylene glycol solvent lead to the formation of layered aluminophosphates with an AFP ratio of 3/4 (see Table 3.9). Therefore, it is expected that using tetraethylenepentamine as template and ethylene glycol as solvent will result in the crystallization of a layered aluminophosphate with an AFP ratio of 3/4. Guided by this prediction, we did... 

Reaction of Stable Solvated Electrons with Water. One of the most promising ways of generating a homogeneous solution of hydrated electrons has been pursued by Dewald, Dye, Eigen, and DeMaeyer (26), who mixed a solution of electrons solvated in ethylenediamine with water. These authors took a solution of Cs in ethylenediamine, a solvent in which solvated electrons are stable, and combined it in a fast-flow mixing cell with a solution of water in ethylenediamine. They then followed the rate of decay of the near infrared absorption band of e ed as a function of water concentration. More recently other active metals have been used and the kinetics fully analyzed (32). The second-order rate constant (20M 1 sec. 1) obtained is attributed to Reaction 16 and compared with... 

Semiconducting nanorods and nanowires were synthesized by y-irradiation at room temperature and the atmospheric pressure. The experiment was carried out in ethylenediamine and pyridine as solvents. Ethylenediamine (en) and pyridine (py) molecules were coordinated with metal ions and had an effect on the shape like nanorods and nanowires (Jo et al. 2006). Semiconducting nanorod and pearl necklace-like nanowire of CdS and CdSe were successfully synthesized by irradiation with a dose of 90 kGy at room temperature and the atmospheric pressure. When nanorods and nanowires were prepared in en and py, the solvent molecules controlled their morphology. From XRD data, the synthesized CdS and CdSe could be observed on the information of crystallinity of them. In nanorod CdS and CdSe, the intensity of the (0 0 2) diffraction peak was extraordinarily strong. This result indicates that the CdS obtained in py have a preferential [0 0 1] orientation. TEM images displayed rod and pearl necklace like morphology with diameters of several nanometers and lengths of upto several microns. For the shape control, en and py were successfully used to replace the surfactant molecules on the surface of nanoparticles. 

The isomerisation of a variety of primary allylic alcohols by treatment with N-lithio-ethylenediamine or -lithio-aminopropylamine in the amine as solvent have been reported. 

Furthermore, PVK ZnS and PVK CdS nanocomposites were synthesized via an in-situ microwave irradiation method [274], and their PL spectra studied by He et al. [275]. As many publications previously reported, these nanocomposites showed a strong emission from PVK and a weak one from metal sulfide nanoparticles. However, if ethylenediamine was employed as solvent to prepare the nanocomposites, two emission peaks attributed to PVK and exciplex could be observed when the nanocomposites were irradiated by light with wavelength of 355 nm. The existence of the emission from PVK should be assigned to the poorly mixed PVK matrix. Additional experiments indicated that no exciplex emission could be observed in the absence of any component of the ethylenediamine-modified nanocomposites. 

I would now like to consider the titration of acidic compounds in nonaqueous solutions. If you wish to titrate an acid in nonaqueous solution, you should choose a solvent that is not acidic and a titrant that is as strong a base as possible. The paper that really aroused people s imagination and created a lot of interest was the one published by Moss, Elliot, and Hall in 1948, in which they introduced ethylenediamine as a solvent. This compound certainly doesn t have any acidic properties and these authors showed that you can titrate phenol, which is normally too weak to titrate as an acid. In recent years, however, the trend has been away from the use of strongly basic solvents because they have a leveling effect on many bases and they are somewhat unpleasant to handle. Solvents now in use are pyridine, which is an inert solvent and a very weak base, acetonitrile, and acetone. Acetone and certain other ketones are surprisingly good. Recently we have done some work with tertiary butyl alcohol, an excellent solvent for certain cases. Sodium or potassium hydroxide can be used as tltrants, but these are not particularly... 

The kinetics of the reaction of [Co2(Et2dtc)s]BF4 with some N-substituted ethylenediamines using CH2CI2 as solvent have also been studied. As with the dithio-oxamides these reactions appear to involve a preequilibrium dissociation (Scheme 3) followed by rate-determining attack by the ligand or solvent on the intermediate. 

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