Charles J. Pedersen (1904-1989) spent more than forty years as a DuPont research chemist in the Organic Chemicals and Elastomer Chemicals departments. Pedersen’s early investigations led to the development of a dramatically improved process for manufacturing tetraethyl lead, an important gasoline additive. His discoveries relating to the degradative effects of heavy metals on petroleum products resulted in thirty patents for antioxidants and other related products. Pedersen’s greatest achievement, however, came toward the end of his career when he discovered a new class of molecules that he called "crown compounds." Twenty years after his ground-breaking discovery was first disclosed publicly, Pedersen shared the Nobel Prize in Chemistry. Pedersen’s research notebooks provide detailed accounts of laboratory preparations and analytical procedures. Also included in this collection are files compiled by Pedersen relating to his original research on crown compounds, as well as his earlier research.