Activity Listings
- Letter from Alden H. Emery, Executive Secretary, American Chemical Society, to Gentlemen, Officers of the Local Sections, American Chemical Society, RE: Explains the problem of the technical manpower and the National Security Resource Board’s request of the American Chemical Society in obtaining information regarding the extent and qualifications of the existing pool of chemists and chemical engineers. The ACS believes this is best done through the local sections and suggests the local sections conduct a special meeting to discuss ways to implement this request. [Letter from O’Brien to Emery, September 18, 1950] [Filed under LP Science: (American Chemical Society: Correspondence, 1950-1964), Box #14.006, Folder #6.3]
- Letter from Charles C. Thomas to LP RE: Thanks him for the reference of Profesor Coryell for the editorship. [Letter from LP to Thomas, September 13, 1950] [Filed under LP Correspondence: (Coryell, Charles D.), #68.2 and LP Correspondence: (T: Correspondence, 1950), #410.15]
- Letter from Charles C. Thomas, Publisher, to E. Bright Wilson, Department of Chemistry, Harvard University, cc. LP RE: Thanks him for considering the position of the editorship. [Letter from Wilson to LP, September 16, 1950] [Filed under LP Correspondence: (Wilson, E. Bright, (Jr.)), #438.5]
- Letter from Evelyn McBain, National Chemical Laboratory, to LP RE: Asks him about gelatine substitute for blood plasma for a man in the Biochemical Division. [Letter from LP to McBain, September 28, 1950] [Filed under LP Correspondence: (N: Correspondence, 1950), #287.17]
- Letter from Harvey F. Mack, President, Mack Printing Company, to Alden H. Emery, American Chemical Society, RE: Writes that due to increased costs and employee benefits, it is necessary to increase the selling rates to six percent. [Letter from Emery to Executive Committee, September 29, 1950] [Filed under LP Science: (American Chemical Society: Correspondence, 1950-1964), Box #14.006, Folder #6.3]
- Letter from LP to Ibert Mellen. [Letter from Mellen to LP, September 9, 1950] [Filed under LP Correspondence: (M: Correspondence, 1950), #256.1]
September 21, 1950
Dr. Ibert Mellen
34-34 Corporal Kennedy Street
Bayside, New York
Dear Dr. Mellen:
I am glad to comment on your letter of September 9, in which you ask about the configuration of the benzene molecule.
There is no doubt that the benzene molecule has a planar configuration, the carbon atoms forming a regular hexagon. The evidence from electron diffraction and spectroscopic studies is overwhelming.
I judge that your attention is that the 120° bond angles of a regular hexagon are too far removed from the tetra-hedral angle 125° between a single bond and a double bond to permit the assumption of the planar hexagonal configuration. This argument is not justified, however. The amount of strain energy associated with a 5° deformation of a bond angle is vey small. The strain energy increases, of course, approximately with the square of the deformation angle. In cyclobutane this angle is 20° - that is, the bond angle of 90° is about 20° less than the tetrahedral angle between single bonds; and the strain energy in cyclobutane is leas than 2 kcal/mol per bond angle. A rough prediction about strain energy in benzene, neglecting the difference between single bonds end double bonds so far as the bending force constants go, would give a strain energy per bond angle l/16th of this value, and hence a small fraction of a kilocalorie per mole per bond angle.
Sincerely yours,
Linus Pauling: W
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September
21, 1950
