3-dimensional electron diffraction and molecular mechanics studies of cellulose polymorphs

摘要: The structure of cellulose I{alpha} has been examined by electron diffraction methods and linked-atom least-squares modeling methods. Only a single chain passes through the triclinic unit cell insuring that all chains are parallel. parameters = 0.674, b 0.593 c 1.036 mn with {alpha} 117.{degrees}, {beta}=113.{degrees} {gamma} 81.{degrees} which forces adjacent to be staggered respect one another approximately c/4. major difference between molecular conformation previous reported for I is existence different conformations successive hydroxymethl groups along backbone. other polymorph, I{beta}, does not differ significantly from proposed I.