BOOK REVIEW
Instrumental Journey
Pierre Laszlo
Shifting and Rearranging: Physical Methods and the
Transformation of Modern Chemistry. Carsten Reinhardt. x +
428 pp. Science History Publications/USA, 2006. $49.95.
Organic spectroscopy, which uses physical methods to determine the
structure of molecules, came of age during the Golden Sixties.
Historian Carsten Reinhardt chronicles the era in his new book,
Shifting and Rearranging: Physical Methods and the
Transformation of Modern Chemistry. As he explains, the
twin engines to lift organic spectroscopy to prominence were nuclear
magnetic resonance spectroscopy (NMR), which drew on the advances in
electronics during World War II (particularly the development of
radar), and mass spectrometry, which was pioneered by engineers in
the 1950s for analyzing the hydrocarbons present in oil.
Organic spectroscopy arose in a bleak landscape. The only
instrumental techniques available just after the war had one sort of
limitation or another: Some (dipolemetry, ultraviolet electronic
spectra interpreted with the Woodward rules, infrared spectroscopy)
were indirect, others (electron diffraction, microwave spectrometry)
were applicable only to small or highly symmetrical molecules in the
gas phase, and still others (x-ray diffraction, for example) were
excruciatingly labor- and time-intensive.
Reinhardt focuses on mass spectrometry in chapters 3 and 5 and on
NMR in chapters 2, 4 and 6. He follows six scientists—Klaus
Biemann, Fred W. McLafferty and Carl Djerassi for mass spectrometry,
and Herbert Gutowsky, John D. Roberts and Richard Ernst for
NMR—whom he terms "lead users" for their mediation
between the chemical industry, instrument makers and academic chemists.
Reinhardt collected his information from interviews with these six
scientists. Such an approach has archival value, but it also has
shortcomings. 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 much that is of substance. It behooves one
to study not just the work of those in the forefront of a discipline
or subdiscipline but also the achievements of scientists who were
less in the limelight; more can be learned from the latter than from
the former—numbers alone see to it.
Important strands of the story involved others whose omission,
partial or total, grates: Frank Anet found the nuclear Overhauser
effect in organic molecules; Elias J. Corey, the synthetic organic
chemist, was well-versed in NMR from the start; Paul Lauterbur
started carbon-13 NMR; Sture Forsén and Ragnar A. Hoffman
devised a relaxational approach to chemical kinetics; Martin
Saunders elucidated the kinetics of the cornerstone bullvalene
rearrangement; John S. Waugh initiated high-resolution NMR of solids.
In addition, historians rightly distrust accounts such as those
elicited by Reinhardt. Interview responses tend to be self-serving,
lack cross-checks and omit the context; they also often conflict
with the narratives that historians themselves are trained to
construct. Moreover, oral history misses testimonies from sources
who died too early. In this instance, an example would be William D.
Phillips, who pioneered NMR of proteins.
However, Reinhardt is an especially skilled narrator, and his
recounting of the twists and turns of early NMR and mass
spectrometry as applied to organic chemistry is captivating. He is
also very good at describing the industry-university nexus, pointing
out, for example, that instrument makers such as Varian Associates
initiated training for users at universities.
A major factor in the success of organic spectroscopy was its close
association with physical organic chemistry, which reached the
zenith of its influence in the 1960s. Several American universities
had departments of chemistry that were powerhouses of physical
organic chemistry. Reinhardt only alludes to this crucial part of
the story.
His narrative describes how the new instrumentation fertilized
chemistry only after having been made part of the chemical culture,
by having been imported by chemists such as the above-named lead
users. Within chemistry, the subdiscipline of physical organic
chemistry was uniquely suited to host the new methodologies. To give
a single example, Gerhard Closs, who was a physical organic chemist
at the University of Chicago, promptly explained the new phenomenon
of chemically induced dynamic nuclear polarization. More generally,
American universities that were, at the time, powerhouses of
physical organic chemistry were the sites for major advances in
chemical knowledge induced by the new instrumentation. This relative
neglect of the key role of physical organic chemists is one of the
few shortcomings of the book.
Information about NMR and mass spectrometry quickly penetrated the
organic community via several outstanding books. A number of these
were written by Reinhardt's six protagonists, but three of the books
had other authors: The Principles of Nuclear Magnetism, by
Anatole Abragam (1961); High-Resolution Nuclear Magnetic
Resonance, by John A. Pople, W. G. Schneider and H. J.
Bernstein (1959); and Applications of Nuclear Magnetic Resonance
Spectroscopy in Organic Chemistry, by Lloyd Miles Jackman (1959).
The OCEANS conference (later renamed the Experimental Nuclear
Magnetic Resonance Conference, or ENC), which was held every spring
at the Mellon Institute in Pittsburgh, translated leading-edge
research into routine laboratory practice. This process was further
facilitated by an informal monthly newsletter (initially Mellon
NMR,and subsequently Texas A&M University NMR
Newsletter). Reinhardt, who is very good on the educational
role of instrument manufacturers, such as Varian Associates, is less
attentive to the self-teaching within the chemical community.
Institutional policies governing the status of the new
spectroscopies were diverse. In the leading German universities, the
conservatism of the ruling professors, who had been nurtured on
synthetic chemistry rather than analytical organic chemistry, saw to
it that specialists in organic spectroscopy were barred from holding
chairs. 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 of it
there was not deemed worthy of the rank of tenured professor.
Accordingly, NMR experts rose to eminence only in schools that were
training engineers, such as MIT, or in departments of chemistry
rather remote from the Ivy League, such as those at the University
of Illinois, the University of Arizona, Florida State University and
Stanford. Others found employment in government laboratories.
Moreover, granting agencies such as the National Science Foundation
were initially shortsighted. Given the high capital expenditures
necessary to acquire the new technologies, they encouraged setting
up university-wide or even regional centers for instruments and
technical staff. (Here they were adapting the model of contemporary
computer centers with their hugely costly mainframe computers.)
There are two sides to the story of the rise of spectroscopy: the
taming of the technology by organic chemists and the profound
changes the new methodologies induced in chemistry. Reinhardt's book
is eloquent on the former but silent on the latter. What a shame!
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 whole story is well worth telling. By covering half of it,
Reinhardt makes a good start toward such a narrative.