Imines ethyleneimines

To avoid oonfusion, it is recommended that names such as ethylene imine, ethyleneimine, azacyclopropaue, and dimethyleuimiiie no longer be tuwd. 

Polyamines are usually open chain compounds with primary, secondary, or tertiary amino groups. Instead of polyamines, polyimines are used without a sharp difference. Actually, imines are compounds with the =N— group or cycles such as ethyleneimine. Examples of oligoamines and polyamines are ethylenediamine, propanediamine, and 1,4-butanediamine and the respective products of condensation such as diethyleneamine, dipropylenetriamine, and triethylenetetramine. The compounds are colorless to yellowish liquids or solids with alkaline reaction. 

Alkoxylated polyethyleneimines are obtained by reacting polyethylene-imine with a molecular weight of 2500 to 35,000 with an excess of propylene oxide and ethylene oxide with respect to the ethyleneimine unit in the... 

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Ethyleneimine (aziridine) and carbon-substituted alkyleneimines are relatively weakly basic compounds [43, 44], This is ascribed to 71-electron delocalization in the ring [44]. By protonation of the imine cycle this aromaticity disappears, and iminium rings are much more readily broken than imines [45], Also the N-alkylethyleneimines are only weakly basic, and they are also more resistant to ring-opening nucleophilic reactions [46]. 

When nitromethane is used as the capping agent instead of ammonia, either the interaction of the nitromethane anion with coordinated ethyleneimine or the addition of nitroethylene to deprotonated coordinated amine yields an intermediate nitroethyl complex. Nitroethylene is formed by a base-catalyzed condensation of nitromethane and formaldehyde. The experimental data suggest that the mechanism of formation of the nitroethyl complex via coordinated imine by Scheme 106 is favoured [101]. 

Ethyleneimine is absorbed readily by the oral, dermal, and inhalation routes. It penetrates the skin so quickly that its toxicity is not decreased even if the area of contact is washed Imin after contact. Urinary excretion accounts for 50% of administered doses. 

Dimethyl-, Diethyl-, Diisopropyl-, Dibutyl-, Dicyclohexyl-, Dibenzyl-, Poly-ethyleneimine, Poly-S-isobutylethylen-imine... 

Poly(ethylene imine). Poly(ethylene amine) (PEI) is the simplest polybase. It can be prepared directly via the acid-catalyzed polymerization of ethyleneimine (aziridine, 24C) (Fig. 40). 24C may be prepared via a number of routes with ethanolamine being a convenient precursor (223). The cationic polymerization of 24C is very rapid due to the release of the ring strain associated with the monomer. However, the synthesis of PEI under these conditions leads to highly branched structnres dne to chain transfer reactions involving the —NH— species in the polymer backbone. Cyclic products can also be prodnced nnder these conditions. Copol5nnerization with an appropriate comonomer can rednce the degree of chain branching (224). 

Recently, blending has also been introduced as a way to improve the conductive behavior of polymer electrolytes. For example, a linear poly(ethyleneimine) (PEl)-graft-PEG is blended with linear poly(ethylene-imine) bearing lithium n-propylsulfonate groups as the lithium source. The use of the PEI backbone promotes the dissociation of ion pairs and stabilizes the macromolecular mixture. The blend shows ionic conductivities up to two orders of magnitude higher than those of polymethacrylate-based systems, around 0.4 mS/cm at room temperature and 5 mS/cm at 80°C. The blend is thermally stable up to 200°C and its electrochemical window is 5 V [21]. 

Although the same experiment could be carried out with an aqueous solution of a low molecular weight amine—cobalt(II) complex, the cobalt-poly (ethylene imine) solution provides the crucial advantage of no amine odor. The cobalt complex attached to the poly(ethyleneimine) cross-linked with poly(epichlorohydrin) was prepared as a rubbery gel or film and studied for its oxygen-absorbing properties [24]. 

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