3.4 Challenges and Opportunities

After World War II，the growth of organic chemistry occurred rapidly，as the field assimilated new results from many other disciplines. The early 1950s，in particular，saw the birth of many subfields of chemistry，including modern organometallic chemistry，beginning with the synthesis and characterization of ferrocene; molecular biology，with the elucidation of the structure of DNA; structural biochemistry，with the description of bonding in proteins and the first crystal structure of a protein; and modern instrumental analysis of organic structures，especially the development of nuclear magnetic resonance （NMR） spectroscopy. All of these propitious discoveries opened many new avenues of chemical research that were incorporated into the growing field of organic chemistry.

A major contribution to the growth of organic chemistry during this century has been the access-ibility of cheap starting materials. Petroleum and natural gas provide the building blocks for the construction of larger molecules. Many drugs，plastics，synthetic fibers，films，and elastomers are made from the organic chemicals obtained from petroleum. As we enter an age of inadequate and shrinking supplies，the use to which we put petroleum looms large in determining the kind of society we will have. Alternative sources of energy，especially for transportation，will allow a greater fraction of the limited petroleum available to be converted to petrochemicals instead of being burned in automobile engines. At a more fundamental level，scientists in the chemical industry are trying to devise ways to use carbon dioxide as a carbon source in the building block molecules.