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Published June 1950 | public
Journal Article

The Crystal Structure of L_s-Threonine


In the three-year investigation described below, we have determined by X-ray diffraction methods the crystal structure of L-threonine. This work has confirmed the molecular structure and the relative configurations of the asymmetric centers as deduced by Rose and co-workers, and has also given detailed information concerning bond lengths, bond angles, hydrogen bonding, and van der Waals packing. Because of our high confidence in the experimental data, we have striven toward the fullest possible utilization of their precision. In this connection we have developed, improved, or used for the first time a number of new techniques: the use of the entire three-dimensional Patterson function, a more rapidly convergent non-centrosymmetric Fourier method, an analytical method for locating Fourier maxima, a "three-dimensional" least squares procedure for the simultaneous refinement of all positional parameters (except those of hydrogen atoms), punched card methods for calculating structure factors and for least squares refinement, and methods for estimating the precision of the parameter determination. Most of these will be described only briefly here, and some will be described in detail elsewhere.

Additional Information

© 1950 American Chemical Society. Received September 12, 1949. Aided by a grant from the National Foundation for Infantile Paralysis, Inc. National Research Council Predoctoral Fellow, 1946-1947. Part of the work described here was included in a dissertation submitted by D. P. Shoemaker to the California Institute of Technology in partial fulfillment of the requirements for the Degree of Doctor of Philosophy. Most of the computational work was done by Miss Lillian Casler and Mrs. Jean Smith, and the figures were prepared by Mrs. Maryellin Reinecke. The authors are grateful to Professor Linus Pauling for his interest, encouragement, and helpful criticism. They wish to express their thanks to Professor Werner Nowacki of Bern, Switzerland, who assisted in the work with the structure factor maps and participated in the computation of the two-dimensional Fourier syntheses and of a second Patterson function. Grateful acknowledgment is also expressed for the financial support of the National Foundation for Infantile Paralysis, Inc.

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October 18, 2023