I would like to thank Dr A. S. Travis for suggesting this paper. Dr Gordon Fray (University of Bristol) and Professor Leo A. Paquette (Ohio State University), and the two referees, made valuable comments on an earlier draft. Thanks are also due to the staff of the Royal Society of Chemistry Library in Burlington House for their help, especially with the translation of Willstatter's tangled prose. This paper was written whilst I was the Royal Society–British Academy research fellow in the History of Science, and I am grateful for generous financial support from these two learned societies.

¹ (a) ‘Strategy and System: Walter Reppe and the Development of Organic Chemicals by I.G. Farben’, given at the 1991 SHOT meeting in Madison, Wisconsin. (b) Also see Morris, Peter J. T., ‘The Development of Acetylene Chemistry and Synthetic Rubber by I.G. Farbenindustrie A.G., 1926–1945’ (Oxford University D.Phil. thesis, 1982).Google Scholar

² 1 have standardized the English name as cyclooctatetraene in the references, in preference to cyclooctatetraene, cyclooctatetraene and the American cycloöctatetraene; the Germans drop the final ‘e’.

³ Keim, Wilhelm, ‘Nickel: an element with wide application in industrial homogeneous catalysis’, Angewandte Chemie International Edition in English (1990), 29, 236.CrossRefGoogle Scholar

⁴ Reppe's curriculum vitae can be found in Edmund Tilley, FIAT interrogation report on Dr Walther [sic] Reppe, 23 August 1946, B/TP 200/888, Imperial War Museum, pp. 9–12; and in J. C. Poggendorf Biographisch-Literarisches Handwörterbuch der exakten Naturwissenschaften. Band Vlla, Teil 3: L-R, East Berlin, 1959, 736–7, also see references therein. Also see Copenhaver, John W. and Bigelow, Maurice H., Acetylene and Carbon Monoxide Chemistry, New York, 1949, pp. xi–xii.Google Scholar For the most complete treatment of Reppe's career so far, see Nikolaus von Kutepow, ‘W. Reppe und die Reppe-Chemie’, unpublished typescript, 73 pp., 1977, BASF Firmenarchiv; I am indebted to Dr Lothar Meinzer (BASF) for a copy of this essay. Surprisingly, no obituaries of Walter Reppe are listed in the collective indices of Chemical Abstracts for the period 1967–76.

⁵ Tilley, , op. cit. (4), 21–2.Google Scholar

⁶ Lasby, Clarence, Project Paperclip: German Scientists and the Cold War, New York, 1971Google Scholar; Bower, Tom, The Paperclip Conspiracy: The Battle for the Spoils and Secrets of Nazi Germany, London, 1987Google Scholar; Gimbel, John, Science, Technology and Reparations: Exploitation and Plunder in Postwar Germany, Stanford, California, 1990.Google Scholar The fullest description of the Allies’ post-war treatment of Reppe is by Kutepow, , op. cit. (4), 20–3Google Scholar; also see Copenhaver, and Bigelow, , op. cit. (4), pp. v–vii.Google Scholar

⁷ Bower, , op. cit. (6), 274Google Scholar, hints that he was an unindicted war criminal, a totally ludicrous suggestion.

⁸ I am indebted to Dr Lothar Meinzer, the archivist of BASF, for information about K. H. O. Meyer and the history of the Hauptlaboratorium.

⁹ For the synthetic rubber research in IG between 1926 and 1945, see: Morris, , op. cit. (1a), 156–70, 178–92, 198–225Google Scholar; Heuck, Claus, ‘Ein Beitrag zur Geschichte der Kautschuk-Synthese: Buna-Kautschuk I.G. (1926–1945)’, Chemiker-Zeitung (1970), 94, 147–57Google Scholar; Konrad, Erich, ‘Über die Entwicklung des synthetischen Kautschuks in Deutschland’, Angewandte Chemie (1950), 62, 423–6CrossRefGoogle Scholar; Logemann, Heino and Pampus, Gottfried, ‘Buna S – Seine grossrechnische Herstellung und seine Weiterentwicklung – ein geschichtlicher Uberblick’, Kautschuk und Gummi, Kunststoffe (1970), 23, 479–86.Google Scholar Also see Plumpe, Gottfried, ‘Industrie, technischer Fortschritt und Staat: Die Kautschuksynthese in Deutschland, 1906–1944/5’, Geschichte und Gesellschaft (1983), 9, 564–97Google Scholar, which places this research in its political and economic context. The links between Walter Reppe and the synthetic rubber research will be explored in ‘Strategy and System’.

¹⁰ All the advances in this section will be treated fully, with references, in ‘Strategy and System’.

¹¹ Author's estimate.

¹² Copenhaver, and Bigelow, , op. cit. (4), p. v.Google Scholar

¹³ Fray, G. I. and Saxton, R. G., The Chemistry of Cyclo-octatetraene and its Derivatives, Cambridge, 1978Google Scholar, provides a good introduction to COT chemistry. Also see Schröder, G., Cyclooctatetraen, Weinheim, 1965Google Scholar, for additional information about the pre-1965 research and the industrial process. The decade between 1965 and 1975 was acutely reviewed by Raquette, Leo A., ‘The renaissance in cyclooctatetraene chemistry’, Tetrahedron (1975), 31, 2855–83.Google Scholar

¹⁴ Travis, A. S., ‘Early intermediates for the synthetic dyestuffs industry’, Chemistry & Industry (1988), 508–14Google Scholar; Ward, E. R., ‘Eminent Victorian: Charles Mansfield’, Chemistry in Britain (1979), 15, 297–304.Google Scholar

¹⁵ For good overviews of the history of aromaticity see Russell, C. A., The History ofValency, Leicester, 1971, 240–57, 304–311Google Scholar; and Fieser, Louis F. and Fieser, Mary, Advanced Organic Chemistry, New York, 1961Google Scholar, chapter 16, ‘History of the benzene problem’. Also see Schiemenz, Günter Paulus, ‘Albert Ladenburg und “Kekulé-Formel” des Benzols’, Mitteilungen (Fachgruppe Geschichte der Chemie, GDCh) (1988), 1, 51–69.Google Scholar A more detailed analysis of the benzene structure debates is provided by Koeppel, Tonja A., ‘Benzene-Structure Controversies (1865–1920)’ (University of Pennsylvania Ph.D., 1973).Google Scholar John Brooke has written a brief critical survey of the historical literature on aromaticity in Recent Developments in the History of Chemistry, London, 1985Google Scholar, chapter 6, ‘Organic chemistry’, 120–2.Google Scholar Two good modern introductions to the topic of aromaticity are Badger, G. M., Aromatic Character and Aromaticity, Cambridge, 1969Google Scholar; and Garratt, P. J., Aromaticity, New York, 1986.Google ScholarLloyd, Douglas, The Chemistry of Conjugated Cyclic Compounds, Chichester, 1989Google Scholar, provides a brief but adequate introduction to the chemistry of benzene, and other carbon rings with alternating single and double bonds including COT.

¹⁶ Albert Ladenburg was the nephew of Seligmann Ladenburg, a banker who was one of the founders of BASF in 1865. Private communication from Dr Lothar Meinzer of BASF.

¹⁷ Willstätter, Richard and Waser, Ernst, ‘Über Cyclo-octatetraen’, Berichte der deutschen Chemischen Gesellschaft (1911), 44, 3423–45CrossRefGoogle Scholar; Willstätter, Richard and Heidelberger, Michael, ‘Zur Kenntnis des Cyclooctatetraen’, Berichte (1913), 46, 517–27.Google Scholar For a good overview of COT research in the pre-Reppe days see Baker, Wilson, ‘Non-benzenoid aromatic hydrocarbons’, Journal of the Chemical Society (1945), 258–62.CrossRefGoogle Scholar

¹⁸ Curiously, no-one before Cope and Overberger (see below under note 52) appears to have recognized the opportunity presented by a facile synthesis of pseudo-pelletierine from glutardialdehyde published in 1924, Menzies, Robert Charles and Robinson, Robert, ‘A synthesis of ψ-pelletierine’, J. Chem. Soc. (1924), 2163–8.CrossRefGoogle Scholar

¹⁹ Pauling, Linus and Wheland, G. W., ‘The nature of the chemical bond. V. The quantum mechanical calculation of the resonance energy of benzene and naphthalene and the hydrocarbon free radicals’, Journal of Chemical Physics (1933), 1, 362–74.CrossRefGoogle Scholar

²⁰ It should be stressed that Pauling did not suggest that COT should be ‘aromatic’, but the many canonical forms of COT certainly hinted that COT might enjoy a degree of resonance stabilization.

²¹ Willstätter, Richard, From My Life, New York and Amsterdam, 1965, 199.Google Scholar This is a translation of Aus Meinetn Leben, edited by Stoll, Arthur, Weinheim, 1949.Google Scholar

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²⁸ Hückel, E., ‘Quantumtheoretische Beiträge zum Benzolproblem I: Die elektronenkonfiguration des Benzols und verwandter Verbindungen’, Zeitschrift für Physik (1931), 70, 204–86.CrossRefGoogle Scholar Also see, Hückel, E., ‘Grundzüge der Theorie ungesättiger und aromatischer Verbindungen’, Zeitschrift für Elektrochemie (1937), 43, 752–88, 827–49.Google Scholar

²⁹ Lord Todd, Alexander and Cornforth, J. W., ‘Robert Robinson’, Biographical Memoirs of Fellows of the Royal Society (1976), 22, 467.Google Scholar I am indebted to Dr Gordon Fray for this reference.

³⁰ Hartmann, H. and Longuet-Higgins, H. C., ‘Erich Hückel’, Biographical Memoirs of Fellows of the Royal Society (1982), 28, 156.Google Scholar

³¹ Reppe, Walter, Schichtling, Otto, Klager, Karl and Toepel, Tom, ‘Cyclisierende Polymerisation von Acetylen I: Über Cyclooctatetraen’, Justus Liebigs Annalen der Chemie (1948), 560, 1–92CrossRefGoogle Scholar; Copenhaver and Bigelow, op. cit. (4), chapter 5, ‘Cyclopolyolefins’.

³² Craig, L. E., ‘Chemistry of eight-membered carbocycles’, Chemical Reviews (1951), 49, 112.CrossRefGoogle Scholar Reppe had suspected that one of the C₁₀H₁₀s was vinylcyclooctatetraene, FIAT report 273, p. 15.Google Scholar

³³ Copenhaver, and Bigelow, , op. cit. (4), 220.Google Scholar

³⁴ In addition to the paper on COT (op. cit. 31), volume 560 of Annalen (1948)Google Scholar also contained Reppe, Walter, Schlichting, Otto and Meister, Herbert, ‘Cyclisierende Polymerisation von Acetylen II: Über die Kohlenwasserstoffe C₁₀H₁₀, C₁₂H₁₂ and Azulen’, 93–104Google Scholar; Reppe, Walter and Schweckendiek, Walter Joachim, ‘Cyclisierende Polymerisation von Acetylen III: Benzol, Benzolderivatives und hydroaromatische Verbindungen’, 104–16.Google Scholar

³⁵ COT may be one of the constituents in the characteristic odour of tomatoes, Fray, and Saxton, , op. cit. (13), 2.Google Scholar

³⁶ As late as 1971, BASF was still supplying academic researchers with free samples of COT (compare Fleming, Ian, Selected Organic Syntheses, Chichester, 1973, 25)Google Scholar, but thereafter it was sold on a commercial basis (private communication from Dr Gordon Fray). This is an interesting example of academic research that was promoted by free supplies of the basic material by industry.

³⁷ Reppe, et al. , op. cit. (31), 33–5Google Scholar; Copenhaver, and Bigelow, , op. cit. (4), 210–12.Google Scholar

³⁸ Copenhaver, and Bigelow, , op. cit. (4), 188.Google Scholar By contrast, Güntcr Wilke has described Reppe's mechanism as ‘a remarkable description for 1948’, Wilke, Gümher, ‘Organo transition metal compounds as intermediates in homogeneous catalytic reactions’. Pure and Applied Chemistry (1978), 678.Google Scholar

³⁹ Elschenbroich, Christoph and Salzer, Albrecht, Organometallics, A Concise Introduction, Weinheim, 1989, 421.Google Scholar Compare the similar assessment in Collman, James P. et al. , Principles and Applications of Organotransition Metal Chemistry, Mill Valley, California, 1987, 613–15.Google Scholar

⁴⁰ Reppe's mechanism: see Reppe, et al. , op. cit. (31), 3–5.Google Scholar Schrauzer's mechanism: Schrauzer, Gerhard N. and Eichler, Siegfried, ‘Zum Mechanismus der Cyclooctatetraen-Synthese nach W. Reppe’, Berichte (1962), 95, 550–61.CrossRefGoogle Scholar Wilke's mechanism: Wilke, , ‘Organo transition metal compounds’, 677–90.Google Scholar

⁴¹ Reppe, et al. , op. cit. (31), 9.Google Scholar

⁴² COT itself, bicyclo[4.2.0]octa-2,4,7,-triene, and tricyclo[5.1.0.0^3.5]octa-1,5,-diene, Reppe, et al. , op. cit. (31), 11–12.Google Scholar

⁴³ FIAT report 967, p. 1.Google Scholar

⁴⁴ BIOS report 137, pp. 26–7.Google Scholar

⁴⁵ Copenhaver, and Bigelow, , op. cit. (4), 219–20.Google Scholar

⁴⁶ Hardie, D. W. F., Acetylene Manufacture and Uses, London, 1965, 74.Google Scholar

⁴⁷ A. Steinhofer's foreword to Schröder, op. cit. (13). The British Oxygen Company also made COT in this period as part of its strategy of moving into acetylene-based chemicals, which was later abandoned (private communication from Dr Gordon Fray).

⁴⁸ Schröder, , op. cit. (13), 70–1.Google Scholar

⁴⁹ Miller, Samuel A., Acetylene, Its Properties, Manufacture and Uses, London, 1965, i, 46.Google Scholar Compare Professor Keim's comment at the beginning of this paper.

⁵⁰ ‘Max-Planck-Institut für Kohlenforschung’, Max-Planck-Gesellschaft Berichte und Mitteilungen, (1982/1987), 85–7Google Scholar; Wilke, G., ‘Beitrage zur nickelorganischen Chemic’, Angew Chemie Inter. Ed. (1988), 27, 189–211CrossRefGoogle Scholar; Keim, , op. cit. (3), 235–44Google Scholar; Weissermel, Klaus and Arpe, Hans-Jürgen, Industrial Organic Chemistry, Weinheim, 1978, 213–15.Google Scholar

⁵¹ Intelligence reports: CIOS report XXXIII–50, ‘Synthetic fibre developments in Germany’, part 2, 626–56 (chiefly a translation of a 1944 report by Reppe); BIOS report 137, ‘Cyclopolyolefines’ (this is a slightly longer version of the report published in CIOS XXXIII–50); BIOS report 352, ‘Cyclopolyolefines’ (4 pp.)Google Scholar; FIAT report 273, ‘Interview with J. W. Reppe’, pp. 13–17; FIAT report 967, ‘Polymerization of acetylene to cyclooctatetraene’ (a large report of 126 pages which contains a translation of the COT section of the post-war ‘Reppe report’ and the text of all the patent applications in this field). These reports are available at the Imperial War Museum and several libraries. In the United States, they were also issued as PB [Publications Board] reports by the Department of Commerce, which are available on microfilm at the Library of Congress. Hecht, Otto and Kröper, Hugo, ‘Neuere Entwicklungen auf dem Gebiete der Chemie des Acetylens und Kohlenoxyds’, in FIAT Review of German Science, Preparative Organic Chemistry, part 1 (ed. Ziegler, Karl), Wiesbaden, 1948, 1–209.Google ScholarReppe, Walter, ‘Neuere Entwicklungen auf dem Gebiet der Chemie des Acetylens und Kohlenoxyds’, Experientia (1949), 5, 93–110.CrossRefGoogle ScholarReppe, Walter, Neue Entwicklungen auf dem Gebiete der Chemie des Acetylen und Kohlenoxyds, Berlin, 1949CrossRefGoogle Scholar; Reppe, Walter, Chemie und Technik der Acetylen-Druck-Reaktionen, Weinheim, 1951Google Scholar (expanded edition, 1952). The ‘Reppe report’, written by Reppe while in American custody in 1945–47, was the basis for Copenhaver and Bigelow, op. cit. (4); and Reppe, J. Walter, Acetylene Chemistry, New York, 1949.Google Scholar

⁵² Cope, Arthur C. and Overberger, C. G., ‘The synthesis of cyclooctatetraene from pseudo-pelletierine’, J. Am. Chem. Soc. (1947), 69, 976CrossRefGoogle Scholar; Cope, Arthur C. and Overberger, C. G., ‘Cyclic polyolefins I: synthesis of cyclooctatetraene from pseudo-pelletierine’, J. Am. Chem. Soc. (1948), 70, 1433–7.CrossRefGoogle Scholar Cope cited ‘German synthetic fibre developments’ (by its US Department of Commerce code, PB 7416) as his source for Reppe's breakthrough.

⁵³ Cope, Arthur C. and Bailey, William J., ‘Cyclic polyolefins II: synthesis of cyclooctatetraene from chloroprene’, J. Am. Chem. Soc. (1948), 70, 2305–9.CrossRefGoogle Scholar It is interesting to note that Bailey and Overberger later became leading polymer chemists.

⁵⁴ For an overview, see Craig, L. E., op. cit. (32), 103–236Google Scholar; and Raphael, R. A., ‘Cyclooctatetraene’, in Non-Benzenoid Aromatic Compounds (ed. Ginsburg, D.), New York, 1959, 465–76.Google Scholar

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⁵⁶ Copenhaver, and Bigelow, , op. cit. (4), 183–6Google Scholar; Raphael, R. A., op. cit. (54), 467.Google Scholar The pioneering X-ray analyses were carried out by Herman Mark, who had worked at I.G. Ludwigshafen from 1926 to 1932 with Kurt Meyer, see Kaufman, H. S., Fankuchen, I. and Mark, H., ‘An X-ray examination of cyclooctatetraene’, J. Chem. Phys. (1947), 15, 414–15CrossRefGoogle Scholar; Kaufman, H. S., Fankuchen, I. and Mark, H., ‘Structure of cyclooctatetraene’, Nature (1948), 161, 165.CrossRefGoogle Scholar

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⁸⁴ Details from Kutepow, , op. cit. (4), 24–5, 30–1Google Scholar; also see his entry in Poggendorf, op. cit. (4).

⁸⁵ Information from Elisabeth Crawford.

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