January 29, 1935
Dear Dr. Sears:
I was of course very much interested to see your results on CCl4. The maxima as we measured them on 281 are [table of maxima data] Average 1.73 Å
You see that your D values lie about 1/4 of the way back to the preceding maximum - which is in agreement with interpreting them as giving maximum slopes.
I have delayed answering to make some slope calculations. Identifying your D values with maxima on an approximate theoretical slope curve, we obtain the above values for C-Cl distances, which average around the probably correct value 1.76 Å, though coming out a little low.
I am enclosing films for Br2 and CH2=CHCl. The former is interesting because we know the Br-Br distance from band spectra, the latter because of the variety in spacing of the rings. I hope you will be able to run these through. We shall continue to calculate theoretical slope curves for them.
I shall be in Cambridge from April 4th to 17th, and shall talk with you then about the apparatus. I am confident that it will put gas-molecule work on a sound basis.
With best regards,
Linus Pauling
January
29, 1935
