ROBERT S. MULLIKEN

By: Jessica Lee, Jimmy Pham, and Kimberly Truong
Block: B


Portrait of Robert Mulliken
Portrait of Robert Mulliken

Click for Large Version

An American chemist and physicist who received the 1966 Nobel Prize for Chemistry for “fundamental work concerning chemical bonds and the electronic structure of molecules.”


Robert S. Mulliken, full name Robert Sanderson Mulliken, was born in Newburyport, Massachusetts on June 7th, 1896. His father was named Samuel Parsons Mulliken. He was a professor who worked on organic chemistry at a school called Massachusetts Instittte of Technology. Mulliken helped his father write his four-volume text on organic compound identification. This made him become an expert on organic chemical nomenclature. When Robert S. Mulliken was a child, he learned the name and classifications of plants. During Roberts young years, he has an amazing memory. An example of when he used this was when he learned German so will, that he skipped the course scientific German, in college. On December 24th, 1929, he married his wife, Mary Helen von Noé , who was the daughter of a geology professor at the University of Chicago. Robert and his wife, Marry, also had two children who where named Lucia Maria (Mrs. John P. Heard) and Valerie Noè.


Robert S. Mulliken attended high school in Newburyport and graduated in 1913, being involved in the science curriculum. Like father like son, Robert received the same scholarship as his father to MIT (Massachusetts Institute of Technology), with a major in chemistry.


When the United States was in World War I, he had a position at American University in Washington D.C, making poison gas with James B. Conant. Nine months later he was then drafted into the Army's Chemical robert-s-mullikan-1.jpgWarefare Service. After the war, he took a job, investigating effects of zinc oxide and carbon black on rubber. He quickly realized that this wasn't the kind of chemistry he wanted to study about. So then in 1919, he entered the PH.D program at the University of Chicago.


He got his doctorate in 1921 for researching the separation of isotopes of mercury by evaporation. He then became interested in strange molecules after exposure to work by Herman I. Schlesinger. At Chicago he had received a grant from National Research Council (NRC), which paid for most of his work in isotopes. He also went to Harvard University to learn spectrograph techniques from Frederick A, Saunders and quantum theory from E, C. Kemble.


In 1942 and 1927, Robert traveled to Europe, working with outstanding people, they all were developing the new quantum mechanics that would eventually replace the old quantum theory. Friedrich Hund, who has been working on quantum interpretations of band spectra of diatomic molecules, was very influential to Robert. In 1927, Robert worked with Hund and as and as a result they developed the molecular orbital theory, know known as the Hund-Mulliken theory.


external image chfa_03_img0573.jpg
Molecular - Orbital theory
Molecular - Orbital theory









The molecular orbital theory( which is known as the MO theory) is a way of determining molecular structure when electrons aren't assigned to a individual bond between atoms. Instead of that, they are treated as a moving electron under the influence of the nuclei in the molecule. This theory is said that each molecule has a set of molecular orbitals which are presumed that the molecular orbital could be written as a weighted sum of the n constituent atomic orbitals which is the equation below.
external image 0d58bf800e4e78d45bd42673db355d44.png

From 1926-1928, he taught in the physics department at New York University(NYU), which was his first recognition as a physicist. Not long after, he then returned to University of Chicago as an associate professor of physics, being promoted to full professor in 1931. He continued to hold positions in both the Chemistry and Physics department at NYU and Chicago, continuing to refine his molecular-orbital theory. And in 1936, Mulliken became a member of the National Academy of Sciences, as the youngest member in the organization history at that time. The Mulliken population analysis, a method of assigning charges to atoms in a molecule, was also named after him.

external image medalje_til_web.jpg

In 1934, he gained a new scale for measuring electronegative of elements. Then in 1942-1945, he directed the Information Office for University of Chicago's Plutonium. Afterward, he developed mathematical formulas to make progress of molecular-orbital theory.


In 1952, he apply quantum mechanics to reactions between Lewis acids and base molecules. Then in 1961, he became Professor of Chemistry and and Physics, continuing studies of molecular structure and spectra, from diatomic molecules to large complex aggregates.
He then retired in 1985 and died of congestive heart failure at his daughter's home at Arlington, Virginia. But was returned to Chicago for burial.


Robert S Mullikens Signature
Robert S Mullikens Signature




REFERENCE
http://nobelprize.org/nobel_prizes/chemistry/laureates/1966/mulliken-bio.html http://en.wikipedia.org/wiki/Robert_S._Mullikenhttp://nobelprize.org/nobel_prizes/chemistry/laureates/1966/mulliken-bio.html http://images.google.ca/images?hl=en&resnum=0&q=ROBERT%20S%20MULLIKEN&um=1&ie=UTF-8&sa=N&tab=wi http://www.chemistryexplained.com/Ma-Na/Molecular-Orbital-Theory.html