Organometallics and Organic Halides
Beyond the functional groups there are two notable subsets of organic compounds: organometallics and organic halides. The basics of organometallics involve organic compounds that have been reacted with group I and group II metals. This can be to create an intermediate to achieve the desired product, such as in a Grignard reaction, or the desired product could include a metal bonded to it. In more modern organometallic compounds, transition metals are heavily used. What classifies an organic compound as an organometallic is the bond between a carbon and the metal. Metals may also be used in a reaction, but it does not bond to the organic compound. In this instance the metal would be acting as a catalyst.
In regards to organic halides, these compounds will have one or more hydrogens in their structure replaced with a halide. The most common halides used are bromine and chlorine. Iodine is very reactive and is used as an intermediate in reactions, but it does not favor staying attached to a carbon. Fluorine is also extremely reactive, but on the flipside of Iodine, it will often react until it has filled all four bonds on the carbon.
Overall, organic chemistry is a very broad topic that involves many compounds composed primarily of carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorous. By understanding functional groups with their ability to react and their limitations, you can understand how some of the most complex organic molecules will function and interact with their environment.
To learn more about chemicals, check out the American Chemical Society.