Kobayashi, Minoru and Sato, Hisaya (2010) Structure Analysis for Hydrate Models of Ethyleneimine Oligomer by Quantum Chemical Calculation. Pharmacology & Pharmacy, 01 (02). pp. 60-68. ISSN 2157-9423
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Abstract
Structure analyses for hydrate models of ethyleneimine oligomer (5-mer as model of PEI) were investigated by quantum chemical calculations. Conformation energies and structures optimized for hydrate models of (ttt)5 and (tgt)5 conformers were examined. Hydrate ratio, h [h = H2O/N (mol)], was set from 0.5 to 2. In anhydrates, (tg+t)5 conformer was more stable (?1.8 kcal/m.u.) than (ttt)5. In hydrates, (ttt)5 conformers were more stable (?0.7 - ?4.3) than (tg+t)5. These results corresponded to experimental results that anhydrous linear PEI crystal changes from double helical to single planar chain in hydration process. Structures calculated for (ttt)5 agreed in those observed for hydrates of PEI. In all (tg+t)5 conformers, O???H bonds between waters were found with the decreases of N???H bonds between imino group and water. The O???H bonds in (tg+t)5 conformer resulted in its high chain torsion, and strongly related with instability and structure change (large swelling).
Item Type: | Article |
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Subjects: | Open Library Press > Chemical Science |
Depositing User: | Unnamed user with email support@openlibrarypress.com |
Date Deposited: | 04 Mar 2023 11:25 |
Last Modified: | 22 Aug 2024 12:34 |
URI: | http://info.euro-archives.com/id/eprint/687 |