Chemical Bonding

The discovery of Chemical Bonding is linked to two scientists, Linus Pauling and Robert Mulliken.

The significance of the chemical bonding as a discovery is that it demonstrated how the new physics of quantum mechanics could explain the basis and fundamentals of a chemical interaction.


In the early 20th century, the nature of the atom has been developed and explained by chemistry and physics. However, in terms of quantum mechanics, these two science disciplines provided different perspectives. One point of contention was the chemical bonding of the element carbon. Whilst physicists and chemists agree on carbon's structure, that is, 6 electrons, 2 in an inner shell and 4 in an outer shell, its bonding issue in terms of the outer reaction of the 4 electrons was more complicated than normally met the eye of the chemists and physicists.


Chemistry Chemical Bonding

Working independently and in different times, chemist Linus Pauling (1901-1994) and physics/chemist Robert Mulliken (1896-1986) are both credited in discovering the chemical bonding as they worked on the mathematical formulation how electron orbitals "hybridized" to form molecular bonds in a process called chemical bonding.

Linus Pauling and Robert Mulliken

In 1928, Linus Pauling suggested his theory and later published an textbook entitled  The Nature of the Chemical Bond and the Structure of Molecules and Crystals.  Pauling and Mulliken were both awarded Nobel Prize in Chemistry for their contribution to Chemical Bonding Theory, Pauling in 1954, "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances", and Mulliken in 1966, "for his fundamental work concerning chemical bonds and the electric structure of molecules by the molecular orbital method".

More about Linus Pauling... his contributions to the theory of the chemical bond include the concept of orbital hybridisation and the first accurate scale of electronegativities of the elements. Pauling worked on the structures of biological molecules, and showed the importance of the alpha helix and beta sheet in protein secondary structure. Pauling's approach combined methods and results from X-ray crystallography, molecular model building, and quantum chemistry. His discoveries inspired the work of James Watson, Francis Crick, and Rosalind Franklin on the structure of DNA, which in turn made it possible for geneticists to crack the DNA code of all organisms. In his later years he promoted nuclear disarmament, as well as orthomolecular medicine, megavitamin therapy, and dietary supplements.  

 
Image Credit:

Chemical Bonding.  research.gov / Public Domain.


Resources:

• Defining Moments in Science.  London: Cassell Books, 2008.

• Symons, Alan. Nobel Laureates 1901-2000. London: Polo Publishing, 2000.

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