Date of Award
8-2005
Degree Type
Thesis
Degree Name
M.S.
Degree Program
Chemistry
Department
Chemistry
Major Professor
Stevens, Edwin
Second Advisor
Thibodeaux, Devron
Third Advisor
Wiley, John
Fourth Advisor
Tarr, Matthew
Abstract
Recently, a one-chain monoclinic unit cell for Cellulose IIII having a single glucose in the asymmetric unit was proposed based on high-resolution diffraction patterns. The new work challenged a two-chain structure published 25 years earlier, although it did not provide new three-dimensional coordinates. Our goals were to solve the structure by modeling, find whether modeling would reject the previously determined two-chain unit cell, and compare the model with the anticipated experimental structure. Combinations of the O2, O3, and O6 hydroxyls produced 54 starting structures. Clusters of 13 cellotetraose chains terminated by methyl groups for each of the 54 starting structures were optimized with MM3(96). Hydroxyl groups on 16 of these 54 structures reoriented to give very similar hydrogenbonding schemes in the interiors, along with the lowest energies. The one-chain cell models had much lower energy. The eight best “up†one-chain models agree well with the structure newly determined by experiment.
Recommended Citation
Ford, Zakhia, "Determining the Crystal Structure of Cellulose III by Modeling" (2005). University of New Orleans Theses and Dissertations. 291.
https://scholarworks.uno.edu/td/291
Rights
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