PRINCETON UNIVERSITY DEPARTMENT OF CHEMISTRY PRINCETON NEW JERSEY Prick Chemical Laboratory Noveinber 4, 1939 Prof e s sor Michae 1 Heidelber ger C olumbia Un iver s it y Colleqe of Physicians 2nd Surgeons E20 West 168th Street, New York Ey dear Professor Heidelberger: There is a remarkable similarity of nroperties between those reported for cyclo-octa- tetraene and the known properties of styrene. It was my understanding that a number of organic chemists wonder whether the products obtained by Willst8tter and his co-workers really did represent the properties of cyclo-octatetraene. It was my understanding also that the lete Professor Kohler spent a considerable amount of time and energy in attempting to obtain cyclo-octatetraene. This suggested to me that he himself was somewhat uncertain that the material previously obtained actually represented the compound sought. I am listing on the enclosed sheet some of the data of the two compounds which suggested the possible identity of the two. The only property which seems to deviate in my view is that on page 519 of your reprint: "The spectrum of the hydrocarbon shows no absorption bands but continuous absorption in the violet beginning at h = 462~,4 at 5 mm. and 490AAat 30 mm. thickness of layer." I wonder if these dosorPtion spectra were msde in the liquid system. If so they cannot be very convincing and what one really ought to do is to examine the absorption spectrum in the vapor phase. Very sincerely yours HST : LC Encl. Styrene 1) B.ptl7 = 43 2) B.Pt76o = 146 21 t (3) nD = 1.5446 (4) d15 = 0.9234 (5) dz = .9251 15 - Cyclooctatetraene 1) B.Ptl7 = 42.2 2) B.Pt715 = 133-135 20 t (3) nD = 1.54225 (4) dl = 0.912 (E;) d20= .920; .923; .925 4 D ibr omi de (6) V.P. 71.5-72 (73) (2nd report) easily loses HBr Tribr0mid.e (from alcohol) (7) 60° sharp Hydr obroinide (8) C,H~-CH-CH~ (cannot be distilled at 760) (9) 3oes not decolorize Br2 in CHC13. Other isomer (10) fiZso4 orange yellow Br B.ptio = 84-86 C6Hs-CH2CH2Br. Bpi, = 92 20 (13) nD = 1.4324 Dibronide (6) 70-71.5 (71) easily loses HBr Tribromide 0 (7) Ein.pt. 55 - solvent not mentioned (unsharp. Hydrobr omide (8) B.pt13 = 85-87 decomposes easily (9) Does not decolorize Bra (10) HzS04 orange yellow From cyclooctene (11) B.pt. 149 , M.pt. 14 0 0 (12) From octatetraene B.pt15 = 39-42 0 does not crystallize 5 -14 (13) nzo= 1.4586 Main Differences in 11-13