Robert S. Mulliken: The Father of Molecular Orbital Theory

A Pioneering Contribution to Chemistry

Robert S. Mulliken is renowned for developing the molecular orbital theory, a fundamental concept in chemistry that revolutionized the understanding of molecular structure and reactivity. His groundbreaking work in the field earned him the Nobel Prize in Chemistry in 1966, solidifying his position as a leading figure in the history of chemistry.

Early Life and Education

Born on June 7, 1896, in Newburyport, Massachusetts, Mulliken grew up in a family of intellectuals. His father, Samuel Parsons Mulliken, was a professor of organic chemistry at the Massachusetts Institute of Technology (MIT). This exposure to chemistry from a young age sparked Mulliken's interest in the subject, and he developed an exceptional memory for organic chemical nomenclature while helping his father with editorial work on a four-volume text on organic compound identification. Mulliken pursued his passion for chemistry at MIT, graduating in 1913 with a scientific curriculum. He went on to major in chemistry, conducting his first publishable research on the synthesis of organic chlorides as an undergraduate. This early start in research would become a hallmark of his illustrious career.

Early Career and World War I

Upon graduating from MIT in 1917, Mulliken took a position at American University in Washington, D.C., where he worked on the development of poison gas under James B. Conant during World War I. After nine months, he was drafted into the Army's Chemical Warfare Service, where he continued to work on chemical warfare agents.

The Birth of Molecular Orbital Theory

In the 1920s, Mulliken began to develop his molecular orbital theory, which proposed that electrons in molecules occupy molecular orbitals rather than atomic orbitals. This concept challenged the prevailing valence bond theory and paved the way for a deeper understanding of molecular structure and reactivity. Mulliken's work on molecular orbital theory led to the development of the molecular orbital method, a computational approach to calculating molecular structure and reactivity. This method has become a cornerstone of modern chemistry, with applications in fields such as materials science, pharmaceuticals, and biotechnology.

Awards and Honors

Mulliken's contributions to chemistry were recognized with numerous awards and honors, including:

• Nobel Prize in Chemistry (1966)
• Priestley Medal (1983)
• National Medal of Science (1964)
• Elliott Cresson Medal (1932)

Legacy and Impact

Mulliken's work has had a profound impact on the development of modern chemistry. His molecular orbital theory has been instrumental in shaping our understanding of molecular structure and reactivity, enabling breakthroughs in fields such as materials science, pharmaceuticals, and biotechnology. Through his research and mentorship, Mulliken inspired generations of chemists, including notable scientists such as Robert S. Berry and Alberte Pullman. His legacy continues to influence the development of new theories and methods in chemistry, ensuring his place as one of the most influential chemists of the 20th century.

Personal Life and Milestones

Mulliken's personal life was marked by a passion for chemistry and a commitment to his work. He married Mary Helen Witners in 1929, and the couple had two children together. Throughout his life, Mulliken maintained an impressive work ethic, publishing numerous papers and books on chemistry, including the seminal work " Molecular Orbitals in Chemistry, Physics, and Biology." He passed away on October 31, 1986, leaving behind a legacy that continues to shape the face of modern chemistry.