Structure Analysis for Hydrate Models of Ethyleneimine Oligomer by Quantum Chemical Calculation
- 1
- 2
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).
- Y. Chatani, T. Kobatake, H. Tadokoro and R. Tanaka, “Structure Studies of Poly(ethyleneimine). 2. Double- Stranded Helical Chain in the Anhydrate,” Macromolecules, Vol. 15, No. 1, 1982, pp. 170-176.
- Y. Chatani, T. Kobatake and H. Tadokoro, “Structure Studies of Poly(ethyleneimine). 3. Structural Characterization of Anhydrous and Hydrous States and Crystal Structure of the Hemihydrate,” Macromolecules, Vol. 16, No. 2, 1983, pp. 199-204.
- Y. Chatani, H. Tadokoro, T. Saegusa and H. Ikeda, “Structure Studies of Poly(ethyleneimine). 1. Structures of Two Hydrates of Poly(ethyleneimine): Sesquihydrate and Dihydrate,” Macromolecules, Vol. 14, No. 2, 1981, pp. 315-321.
- T. Hashida, K. Tashiro, S. Aoshima and Y. Inaki, “Structural Investigation on Water-Induced Phase Transitions of Poly(ethyleneimine). 1. Time-Resolved Infrared Spectral Measurements in the Hydration Process,” Macromolecules, Vol. 35, No. 11, 2002, pp. 4330-4336.
- H. Dong, J. K. Hyun, C. Durham and R. A. Wheeler, “Molecular Dynamics Simulations and Poly(ethyleneimine) Models,” Polymer, Vol. 42, No. 18, 2001, pp. 7809-7817.
- S. Wang, L. DeBolt and J. E. Mark, “Configurational Analysis of Linear Poly(ethyleneimine),” Polymeric Preprints, Vol. 34, No. 2, 1993, pp. 478-479.
- S. E. Boesch, S. S. York, R. Frech and R. A. Wheeler, “An Experimental and Computational Investigation of the Structure and Vibrations of Dimethylethylenediamine, a Model for Poly(ethyleneimine),” PhysChemComm, Vol. 4, 2001, pp. 1-10.
- Y. Sasanuma, S. Hattori, S. Imazu, S. Ikeda, T. Kaizuka, T. Iijima, M. Sawanobori, M. A. Azam, R. V. Law and J. H. G. Steinke, “Conformational Analysis of Poly(ethyl- eneimine) and its Model Compounds: Rotational and Inversional Isomerizations and Intramolecular and Intermolecular Hydrogen Bonds,” Macromolecules, Vol. 37, No. 24, 2004, pp. 9169-9183.
- H. Kusanagi, “Quantum Chemical Examination on the Double-Stranded Helix Models of Poly(ethyleneimine),” Polymer Preprints Japan, Vol. 53, No. 2, 2004, pp. 3610-3611.
- D. Diabate, A. Yapo, A. Trokourey, A. Kone and B. Fahys, “Study of Structural and Electronic Properties of Polyethylenimine Hemihydrate,” Physical and Chemical News, Vol. 37, 2007, pp. 122-126.
- M. Kobayashi and H. Sato, “Conformational Analysis of Ethylene Oxide and Ethylene Imine Oligomers by Quantum Chemical Calculation,” Polymer Journal, Vol. 40, No. 4, 2008, pp. 343-349.