W. Kratschmer, K. Fostiropoulos, D.R. Huffman, "The infrared and ultraviolet absorption spectra of laboratory-produced carbon dust: evidence for the presence of the C60 molecule," Chemical Physics Letters, 170:167-70, 1990. W. Kratschmer, L.D. Lamb, K. Fostiropoulos, D.R. Huffman, "Solid C60: a new form of carbon," Nature, 347:354-58, 1990.
Wolfgang Kratschmer (Max Planck Institute for Nuclear Physics, Heidelberg, Germany): "We stumbled over the soccer ball-shaped C60 molecule when we produced soot in order to investigate whether such dusty material occurs in interstellar space. It may be interesting to note that H.W. Kroto [University of Sussex, England] and R.E. Smalley [Rice University, Houston], the actual discoverers of this unique molecule, started their work with a very similar objective.
"Our contribution to this field is the discovery of an exceedingly simple and efficient method to produce C60 and other closed-cage carbon molecules, such as C70, in bulk quantities. The properties of solid C60 known so far show that it is a soft, semiconducting, and fairly volatile material that crystallizes into the cubic closed packing of spheres. Appropriately doped, it becomes conducting and even superconducting below a temperature of about 20 degrees K.
"Chemists currently are busy isolating, purifying, and characterizing other stable-cage carbon molecules and their solid forms. They have successfully attached and removed hydrogen (and other groups) onto the outside of C60; chemistry on the inside of the cage should be possible as well. Elementary carbon has been shown to be a system able to form many surprising arrangements. There may be surprises waiting in the future."
R.H. Crabtree, "Dihydrogen complexes: some structural and chemical studies," Accounts of Chemical Research, 23:95-101, 1990.
Robert H. Crabtree (Yale University, New Haven, Conn.): "The discovery by Greg Kubas [Los Alamos National Laboratory, N. Mex.] that hydrogen can bind to metals while retaining the H-H bond was one of the most exciting recent developments in inorganic chemistry. It forced us to rethink many of our ideas on hydrides and hydrogenation catalysis. It may well be important in enzymatic hydrogen activation.
"Like many others, we had made H2 complexes but failed to identify them for lack of a good detection method. Our nuclear magnetic resonance method, which detects the short H-H distance, has allowed many additional examples to be identified and studied.
"Can higher Hn species exist? More recently, we found an H3 on one reaction pathway we were studying, and we have some candidates for stable H3 complexes. We now need to know more about what reactions such binding allows and what other types of bonds can be bound in the same way."