The Nobel Prize in Chemistry 1954 was awarded to Linus Pauling "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances".
 

When, in the early nineteenth century, Dalton had produced experimental proofs that matter consists of atoms it was not long before an explanation was sought of the forces that bind the atoms together. In 1819 when Berzelius presented his theory he could apply it almost exclusively to inorganic substances; only few organic substances were known as pure compounds, and the study of these was difficult due to their complicated and often insufficiently known composition. In the late nineteen thirties Pauling and his colleagues had already begun to determine with X-rays the structure of amino acids and dipeptides, that is to say, compounds of relatively simple structure containing what may be called fragments of proteins.