Atlas of Steroid Structure : Volume 2

William L. Duax

ISBN 10: 1475704283 / ISBN 13: 9781475704280

Published by Springer US, Springer New York, 2012

About this Item

Druck auf Anfrage Neuware - Printed after ordering - 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.

Seller Inventory # 9781475704280

Bibliographic Details

• Title: Atlas of Steroid Structure : Volume 2
• Publisher: Springer US, Springer New York
• Publication Date: 2012
• Language: English
• ISBN 10: 1475704283
• ISBN 13: 9781475704280
• Binding: Taschenbuch
• Condition: Neu
• Dimensions: 279W x 210H x 41D millimeters 279 millimeters width by 210 millimeters height by 41 millimeters depth
• Weight: 1826 grams

About this title

Synopsis

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.