Lipscomb, William Nunn, Jr. (1919-), an American inorganic chemist, received the 1976 Nobel Prize in chemistry for his studies on the structure and bonding mechanisms of boranes, complex compounds of boron and hydrogen.

Lipscomb was born Dec. 9, 1919, in Cleveland to Edna (Porter) and William N. Lipscomb. The family moved to Lexington, Kentucky, and Lipscomb studied at the University of Kentucky.

Lipscomb went to graduate school at the California Institute of Technology (Caltech), studying physics and then changing to chemistry, influenced by his professor and later doctoral adviser, Linus Carl Pauling, two-time Nobel Prize-winning American chemist.

After an interruption in his studies to do wartime research for the U.S. government from 1942 to 1945, Lipscomb completed his Ph.D. degree at Caltech. He then taught at the University of Minnesota and in 1959 became professor of chemistry at Harvard University. At Caltech, he became interested in the chemical bonding in boron hydrides, also known as boranes. Borane chemistry was regarded as very difficult, because boranes are volatile and can be explosive.

During the 1950's, Lipscomb was able to determine the molecular structures of many boranes through a process called X-ray diffraction analysis, which measures the changes in radiation intensity of X rays projected into a material. Chemists at the time thought that the atoms in borane molecules were held together by covalent bonds. A covalent bond forms when two atoms are held together by a shared pair of electrons. However, the borane structures Lipscomb found could not be explained according to this theory. Lipscomb suggested that some of the atoms in borane molecules were creating three-center bonds, in which an electron pair unites either three boron atoms or two boron atoms and one hydrogen atom.

Lipscomb's theory of three-centered bonds explained the borane structures. It also predicted the possibility of new compounds, which later allowed chemists to create many new molecules. Lipscomb's boranes also showed promise in radiation cancer therapy.