Science, Tech, Math › Science Acyl Group Definition and Examples Learn What an Acyl Group Is in Chemistry Share Flipboard Email Print Acyl Group Chemical Structure. Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated May 06, 2019 Organic chemistry defines several moieties or functional groups. The acyl group is one of them: Acyl Group Definition An acyl group is a functional group with formula RCO- where R is bound to the carbon atom with a single bond. Typically the acyl group is attached to a larger molecule such that the carbon and oxygen atoms are joined by a double bond. Acyl groups are formed when one or more hydroxyl groups are removed from an oxoacid. Even though acyl groups are almost exclusively discussed in organic chemistry, they may be derived from inorganic compounds, such as phosphonic acid and sulfonic acid. Acyl Group Examples Esters, ketones, aldehydes and amides all contain the acyl group. Specific examples include acetyl chloride (CH3COCl) and benzoyl chloride (C6H5COCl). Sources IUPAC (1997). Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). "Acyl groups". doi:10.1351/goldbook.A00123Smith, Michael B. (2013). March's Advanced Organic Chemistry. Hoboken, NJ: Wiley. p. 857. ISBN 978-0-470-46259-1.