3.2 The Subdisciplines of Organic Chemistry

In the study of organic chemistry，you will encounter several subdisciplines. Three areas that have been particularly important during development of the field and are still important today are physical organic chemistry，bioorganic chemistry and organometallic chemistry.

Physical organic chemistry encompasses studies of the pathways of chemical reactions of organic compounds and a systematic examination of all the variables involved in such processes. The structure and bonding of organic molecules as well as chemical reactions and their mechanisms （how reactions occur） fit into this broad subdiscipline.

Bioorganic chemistry concentrates on those compounds obtained from nature what we call nat-ural products. Researches in this area focus on how such molecules are made and how they are involved in biochemical transformations. Bioorganic chemistry，in some respects，overlap with the study of molecular biology.

Organometallic chemistry is the study of compounds in which carbon is bonded to a metal atom or ion. Although many aspects of organometallic chemistry research focus on the properties of the metal ions themselves，and thus might be better classified as inorganic chemistry，the use of metalcarbon bonded substances to prepare new materials constitutes an enormously large subdiscipline. Because many organometallic compounds are extremely reactive toward oxygen and water，the discovery of an organometallic species in nature，vitamin B₁₂，made us realize that compounds having a metalcarbon bond are sometimes quite stable and carry out chemical reactions that are otherwise difficult to do in a selective way.

Another way to classify subdisciplines of organic chemistry is to look at what organic chemists "do". For example，those interested in preparing new substances are said to be involved in synthetic organic chemistry．Those whose attention is focused on characterizing molecular structures study ana-lytical organic chemistry or organic spectroscopy. Chemists specializing in molecules with very high molecular weights，especially those substances that have regularly repeating structural motifs，are organic polymerchemists. The use of light to carry out chemical reactions of organic compounds has led to the growth of the field of organic photochemistry.