Month: May 2008

Just as with ferrocene, 1 the formula first written for diborane B2H6 was orthodox, in conformity with the usual paradigmatic rules regarding molecular structure. And it was wrong. Correcting the mistake showed an extremely unusual bonding picture for the molecule. Just as in the ferrocene case, it opened up a whole new chapter of chemistry, later recognized with the award of a Nobel prize to William N. Lipscomb in 1976 for “his studies on the structure of boranes illuminating problems of chemical bonding.”

I shall highlight here only a few episodes from the diborane story. In 1937, a former student of Linus Pauling, Simon H. Bauer – incidentally he is still active in research at Cornell, at the age of 88 – applied the technique of electron diffraction, a tool which he had learned to use at Caltech with Pauling, to diborane. He found and he reported a structure analogous to that of ethane, which therefore he wrote as H3B-BH3. 2 In 1942, Bauer reiterated his contention of the ethane-like structure for diborane. 3 At the same time of the early 1940s, H.I. Schlesinger, a chemistry professor at the University of Chicago, was also working on boron compounds. One of the reasons was his involvement in the Manhattan Project: it was thought that an isotope separation could be devised for uranium using such derivatives. In any case, Schlesinger was very much interested in the structure of diborane.

Science often advances upon willful transgression of a seeming interdiction. Examples which leap to a chemist’s mind are noble gas compounds, strained hydrocarbons such as tetrahedrane, activation (by organometallics) of even methane, and, to mention just one brilliant, more recent achievement, inclusion of an allene within the confines of a six-membered ring while preventing its conversion into a benzenoid. Such feats put all the cunning of a scientist into coaxing and, yes, coercing the system at hand to obey instructions from one’s daring imagination. As always, it is hard. Not for nothing is our playroom called a laboratory. And when the task is done and the time arrives to convey to others (who might not be privy to the anguish of the work) all that struggle and the majesty of the achievement, the scientist quite naturally lapses into metaphor. One such, founded in male 19th century language as much as in history, is some more or less prurient variant of “Unveiling the Secrets of Nature.” Another, evoking the thorny, twisted path to understanding and the long hours of toil in the laboratory, is “Wrestling with Nature.”