Weight amine

Reactivity Acrolein is a highly reactive chemical, and contamination of all types must be avoided. Violent polymerization may occur by contamination with either alkaline materials or strong mineral acids. Contamination by low molecular weight amines and pyridines such as a-picoline is especially hazardous because there is an induction period that may conceal the onset of an incident and allow a contaminant to accumulate unnoticed. After the onset of polymeriza tion the temperature can rise precipitously within rninutes. 

Anionic extractants are commonly based on high molecular weight amines. Metal anions such as MnO or ReO can be exchanged selectively with inorganic anions such as Cl or The equiHbrium for a quaternary onium compound of organic radicals R for two anion species A and B ... 

Detergent Additives. Diesel engine deposits ate most troublesome in the fuel dehvery system, ie, the fuel pump and both fuel side and combustion side of the injectors. Small clearances and high pressures mean that even small amounts of deposits have the potential to cause maldistribution and poor atomization in the combustion chamber. The same types of additives used in gasoline ate used in diesel fuel. Low molecular weight amines can also provide some corrosion inhibition as well as some color stabilization. Whereas detergents have been shown to be effective in certain tests, the benefit in widespread use is not fully agreed upon (77). 

One other characteristic of amines is their odor. Low-molecular-weight amines such as trimethyjamine have a distinctive fishlike aroma, while diamines such as 1,5-pentanediamine, commonly called cadaverine, have the appalling odors you might expect from their common names. 

Triple bonds can also be selectively reduced to double bonds with DIBAL-H, " with activated zinc (see 12-36), with hydrogen and Bi2B-borohydride exchange resin, ° or (internal triple bonds only) with alkali metals (Na, Li) in liquid ammonia or a low-molecular-weight amine.Terminal alkynes are not reduced by the Na—NH3 procedure because they are converted to acetylide ions under these conditions. However, terminal triple bonds can be reduced to double bonds by the... 

Coelenterates and Echinoderms. Coelenterate and echinoderm toxins range from small molecular weight amines, to sterols, to large complex carbohydrate chains, to proteins of over 100,000 daltons. Molecular size sometimes reflects taxonomy, e.g., sea anemones (Actiniaria) all possess toxic polypeptides varying in size from 3,000 to 10,000 daltons while jellyfish contain toxic proteins (ca. 100,000 daltons). Carotenoids have been isolated from Asterias species (starfish), Echinoidea (sea urchins), and Anthozoans such as Actiniaria (sea anemones) and the corals. These are sometimes complexed with sterols (J5). 

Perfluoroalkyl)ethane thiols have been used as precursors to fluorinated surfactants and products for hydro- and oligophobic finishing of substrates such as textiles and leather (1). The synthesis of 2-(perfluoroalkyl)ethane thiol and a byproduct bis-(-2-perfluoroalkylethane)-disulfide (5-10%) has been practiced via the reaction of 2-(perfluoroalkyl)ethane iodide with thiourea to form an isothiuronium salt which is cleaved with alkali or high molecular weight amine as shown in Equation 1 for 2-(perfluorohexyl)ethane iodide (1). 

Reduction of acetylenes can be done with sodium in ammonia,220 lithium in low molecular weight amines,221 or sodium in HMPA containing /-butanol as a proton source,222 all of which lead to the A-alkene. The reaction is assumed to involve successive electron transfer and protonation steps. 

Other high molecular weight amines to have been successfully used for adduct purification include the aza-crown macrocycles Me4-14-ane-N4 and Me6-18-ane-N6.48 These reversibly form adducts with indium and gallium alkyls, such as [(Et3Ga)4(Me6-18-ane-N6)], [(Et3Ga)6(Me6-18-ane-N6)], [(Pr13Ga)4(Me6-18-ane-N6)], and [(Pr13Ga)4(Me4-14-ane-N4)].49 Formation of... 

Yang et al. [294] determined nanomolar quantities of individual molecular weight amines (and organic acids) in sea water. Amines were diffused from the sample across a hydrophilic membrane to concentrate and separate them from inorganic salts and most other dissolved organic compounds. Methylamine, dimethylamine, and trimethylamine were all found in measurable amounts in sea water. 

The concept of repetitive growth with branching was first reported in 1978 by Vogtle [4] (University of Bonn, Germany) who applied it to the construction of low molecular weight amines. This was followed closely by the parallel and independent development of the divergent, macromolecular synthesis of true dendrimers in the Tomalia Group [5,6] (Dow Chemical Company). The first... 

Nanomolar concentrations of low molecular weight amines and organic acids dissolved in seawater can be preconcentrated up to 1000-fold by diffusion across hydrophobic membranes and collecting in HC1 or NaOH solutions, respectively. Of a set of 25 amines investigated, excepting pyrrole, all showed practically quantitative trapping efficiency76. 

Histamine (2-[4-imidazole] ethylamine) is a low-molecular-weight amine synthesized from L-histidine exclusively by histidine decarboxylase. It is produced by various cells throughout the body, including central nervous system neurons, gastric mucosa parietal cells, mast cells, basophils and lymphocytes [1-4]. Since its discovery as a uterine... 

The tertiary and quaternary amine bases are viscous liquids at room temperature and infinitely soluble in nonpolar solvents, but only slightly soluble in water. The solubility of the ion-pair RNH L in organic solvents depends on the chain length and on the counterion, LT the solubility of TLA HCl in wet benzene is 0.7 M, in cyclohexane 0.08 M, in CHCI3 1.2 M, and in CCI4 0.7 M. Nitrate and perchlorate salts are less soluble, as are lower molecular weight amines. 

The compatibility of the quaternary amlne-contalnlng NTMP with the nltrlle-modlfled epoxy adhesive, which leads to a bond that falls only within the adhesive (l.e., cohesive failure) can be explained. The FM 123-2 adhesive contains the storage-stable curing agent, dlcyanodlamlde, which does not release low-molecular weight amines until It becomes soluble In the resin above 90°C. (Equation 2) (25)... 

These reactions are often conducted in water, or in acetone-water mixtures for higher molecular weight amines.Magnesium sulfate is frequently used as an additive in these reactions to control solution pH. 1,3,5,7-Tetranitroadamantane (71) has been obtained via the permanganate oxidation of the hydrochloride salt of 1,3,5,7-tetraaminoadamantane (70) (Table 1.7). The 45 % yield for this reaction reflects a relative yield of 82 % for the oxidation of each of the four amino groups. 

Sodium and lithium are the most common metals, and diethyl ether, tetrahydro-furan, and HMPA are often used as cosolvents to overcome solubility problems. The Benkeser method,37 204 employing lithium in low-molecular-weight amines (methylamine, ethylamine, ethylenediamine), is a more powerful reducing agent... 

The following is valid, only when GA is reacted with low molecular weight amines. 

It has already been reported that the weight loss of as-synthesized MMSs depends on the kind of the template used in the synthesis [17]. This is an obvious consequence of the fact that different templates decompose and thermodesorb at different temperatures. However, it was somewhat unexpected that the decomposition/desorption of the same kind of the template may be dramatically influenced by the framework composition of materials [4,10-14]. This can be understood as an influence of the framework structure on the process of Hoffmann elimination of alkylammonium to the corresponding alkene and low molecular weight amine [4,8], This decomposition process leads not only to the elimination of the electrostatic framework-template interactions but also to the formation of decomposition products of lower molecular weight than that of the surfactant. Thus, the framework-surfactant interactions are crucial factors determining the thermogravimetric behavior. 

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