Carsten Reinhardt, Shifting and Rearranging. Physical Methods and the Transformation of Modern Chemistry.
Science History Publications, Watson Publishing International, Sagamore Beach, MA, 2006, ix + 428 pp., ISBN 0-88135-354-X, $ 49.95.
Organic spectroscopy applies physical methods to determining the structure of the molecules organic chemists isolate, make and test. It came of age during the Golden Sixties. The twin engines to lift it to prominence were mass spectrometry (ms), which engineers developed in the nineteen-fifties for analyzing hydrocarbons present in oil; and nuclear magnetic resonance (nmr), discovered in the aftermath of World War II. Carsten Reinhardt, an historian from the University of Regensburg, Germany, has now chronicled the early times of organic spectroscopy.
Organic spectroscopy rose in a bleak landscape. Available instrumental techniques were indirect (dipolemetry, ultraviolet electronic spectra interpreted with the Woodward rules, infrared spectroscopy), limited to small or highly symmetrical molecules in the gas phase (electron diffraction, microwave spectrometry), or yet excruciatingly labor- and time-intensive (X-ray diffraction).
A major factor in the success of organic spectrocopy was its close association with physical organic chemistry, then (1960s) at the zenith of its influence. It thrived in American departments of chemistry which were powerhouses of physical organic chemistry, such as UCLA, where Frank Anet interfaced with Saul Winstein and Donald J. Cram (which led to his discovery of the nuclear Overhauser effect); the University of Utah, where David M. Grant had, among his colleagues, Henry Eyring, Josef Michl, Peter J. Stang and Cheves Walling; Yale, where likewise Martin Saunders thrived in the company of Jerome A. Berson and William von Eggers Doering; MIT, where John S. Waugh was a colleague of C. Gardner Swain; not to mention cases in which the two personas met in a single person, such as John D. Roberts at Caltech, or Gerhard L. Closs at the University of Chicago who promptly explained the brand-new phenomenon of chemically-induced dynamic nuclear polarization.
Nmr and ms quickly penetrateded the organic community with outstanding books: for nmr, by A. Abragam (1961), Pople, Schneider and Berstein (1959), J.D. Roberts (1959 and 1961), L.M. Jackman (1959); and, for ms, by K. Biemann (1962), C. Djerassi et al. (1964), and F.W. McLafferty (1966). The OCEANS conferences (later renamed ENC), held in the spring at the Mellon Institute in Pittsburgh, transferred leading edge research into routine laboratory practice. An informal monthly newsletter (Mellon NMR, subsequently TAMU NMR) prolonged them.
Institutional policies governing the status of the new spectroscopies were diverse. Conservatism of the ruling professors, nurtured on synthetic rather than on analytical organic chemistry, saw to it that organic spectroscopy was barred from chairs in the leading German universities. The dominant American mentality was somewhat similar. The enormously influential chemistry department at Harvard University viewed nmr as an ancillary technique; the person in charge there was not deemed worthy of a tenured professorial rank. Accordingly, nmr experts rose to eminence only in schools training engineers, such as MIT, or in departments of chemistry rather remote from the Ivy League, such as Arizona, Florida, Stanford or SUNY at Stony Brook. Others found employment in government laboratories, such as the Jet Propulsion Laboratory in Pasadena, or Livermore at Berkeley.
Moreover, granting agencies such as the National Science Foundation were initially short-sighted. Given the high capital expenditures, they encouraged setting-up university-wide or even regional centers for instruments and their technical staff, on the model of the contemporary computer centers, imposed likewise by the hugely costly mainframe computers.
Reinhardt is an especially skilled narrator and his recounting of the twists and turns of early nmr and ms, as applied to organic chemistry, is captivating. He is also very good on the industry-university nexus, instrument makers such as Varian Associates initiating users’ training. His book focusses on the role of half-a-dozen leaders: Herb Gutowsky, Jack Roberts and Richard Ernst for nmr; Carl Djerassi, Klaus Biemann and Fred McLafferty for ms.
To define a field by its leaders is akin to viewing a mountain range only in terms of its highest peaks. It leads the historian to miss out on the substance. It behooves one to study, not only leaders of the discipline or sub-discipline, more so the achievements of scientists who did not enjoy the limelight to a similar extent. There is more to be learned from the latter than from the former, it may safely be contended. Numbers alone see to it.
Reinhardt collected his information from interviews with the six above-named scientists. Such an approach has archival value, but it lacks in significance. Historians distrust such accounts, deservedly, because such interviews are self-serving, lack cross-checks, omit the context and conflict with the narratives themselves are trained to construct. There were two sides to the story, the taming of spectroscopy by organic chemists, and the changes the new methodologies induced in chemistry. Reinhardt’s book is eloquent on the former, but silent on the latter.
And yet! The enrichment of organic chemistry by nmr was bedazzling. Conformational analysis took off in a big way. Fluxional molecules, starting with bullvalene as a seminal case, presented chemists with a fascinating new aspect of molecular reality. Organometallic chemistry blossomed enormously on the strength of multinuclear magnetic resonance. Nmr took over from existing physical methods, too. For instance, it replaced polarimetry in determinations of enantiomeric excesses in reactions.
The story was well worth telling. Reinhardt’s book is a good start towards such a narrative.
Pierre Laszlo is emeritus professor of chemistry at Ecole polytechnique, Palaiseau, France and University of Liège, Belgium. Together with Peter J. Stang, he authored Organic Spectroscopy (Harper and Row, New York, 1971). He taught a course of instrumental analysis at Cornell, jointly with Fred W. McLafferty. His current interests combine history of chemistry and science writing.