Atlas of Steroid Structure

Volume 2

  • Jane F. Griffin
  • William L. Duax
  • Charles M. Weeks

Table of contents

  1. Front Matter
    Pages i-v
  2. Introduction

    1. Jane F. Griffin, William L. Duax, Charles M. Weeks
      Pages 1-22
  3. Data

    1. Front Matter
      Pages 23-23
    2. Jane F. Griffin, William L. Duax, Charles M. Weeks
      Pages 25-166
    3. Jane F. Griffin, William L. Duax, Charles M. Weeks
      Pages 167-355
    4. Jane F. Griffin, William L. Duax, Charles M. Weeks
      Pages 356-625
    5. Jane F. Griffin, William L. Duax, Charles M. Weeks
      Pages 627-655
  4. Back Matter
    Pages 657-754

About this book

Introduction

model. In general, the mean atomic positions and the geometrical parameters calculated from them are more accurate if the more sophisticated anisotropic model has been used for the thermal motion during structure refinement. Low temperature data collection also results in more accurately determined structures. By decreasing the temperature at which data is collected, the intensities and number of data observed is increased. Since hydrogen atoms have only a single electron, they scatter X-rays very weakly, and they can be observed experimentally only if the data are of good quality. Finally, in the absence of systematic errors in data collection or refinement, tae greater the number of observed data relative to the number of independent atoms, the better the atomic resolution will be. Table 1 is a summary of the information used in assessing the reliability of a structure. Neutron diffraction is the result of interaction of atomic nuclei with a neutron beam. The intensi ty of the diffracted beam is not proportional to atomic number. Hydrogen, deuterium, carbon, oxygen and nitrogen scatter neutrons with almost equal intensity. In addition, hydrogen and deuterium scatter out of phase so that they can be distinguished wita high precision. 20-Methyl-5-pregnene-3S,20-diol (PR104N) is the only steroid which has been the subject of a neutron diffraction study. The study was undertaken to examine the stereospecificity of Grignard addition using deuterated reagent. Data were collected at 123°K.

Keywords

X-ray atoms carbon diffraction electron experiment hydrogen hydrogen atom low temperature neutron neutron diffraction nitrogen oxygen structure temperature

Editors and affiliations

  • Jane F. Griffin
    • 1
  • William L. Duax
    • 1
  • Charles M. Weeks
    • 1
  1. 1.Medical Foundation of BuffaloBuffaloUSA

Bibliographic information

  • DOI https://doi.org/10.1007/978-1-4757-0426-6
  • Copyright Information Springer-Verlag US 1984
  • Publisher Name Springer, Boston, MA
  • eBook Packages Springer Book Archive
  • Print ISBN 978-1-4757-0428-0
  • Online ISBN 978-1-4757-0426-6
  • About this book