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The Determination of the Crystal Structure of Potassium Picrate


Bettman, Max (1952) The Determination of the Crystal Structure of Potassium Picrate. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/1S9K-H086.


The crystal structure of potassium picrate has been determined and refined to a considerable degree of accuracy by means of x-ray diffraction techniques. Most of the refinement was carried out by the use of least squares methods, by making use of about half of the three dimensional data obtainable from copper Kα radiation.

The benzene ring of the picrate ion is nearly planar, the deviation from planarity being within experimental error. The para nitro group is twisted 6° out of the plane of the benzene ring, apparently due to ionic attraction of the oxygen atoms to neighboring potassium ions. The ortho nitro groups are twisted 27° out of the plane of the benzene ring due to steric hindrance between the phenol oxygen and its two nearest oxygen neighbors in the ortho nitro groups. Chemical bonds of a given species, such as carbon-carbon bonds, show considerable variations in length. All these variations are quite reasonable in the light of well known principles of structural chemistry.

The packing of the structure seems to be largely determined by the ionic attraction between potassium ions and five out of the seven oxygen atoms of each picrate ion. There also exist some rather short van der Waals contacts between neighboring picrate ions.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Chemistry and Physics)
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Minor Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Hughes, Edward Wesley (advisor)
  • Donohue, Jerry (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1952
Funding AgencyGrant Number
Naval Ordnance Test StationUNSPECIFIED
Record Number:CaltechTHESIS:09272017-100629593
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10461
Deposited By: Benjamin Perez
Deposited On:27 Sep 2017 17:33
Last Modified:10 May 2023 22:56

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