In chemistry, a ring is an ambiguous term referring either to a simple cycle of atoms and bonds in a molecule or to a connected set of atoms and bonds in which every atom and bond is a member of a cycle (also called a ring system). A ring system that is a simple cycle is called a monocycle or simple ring, and one that is not a simple cycle is called a polycycle or polycyclic ring system. A simple ring contains the same number of sigma bonds as atoms, and a polycyclic ring system contains more sigma bonds than atoms.
Four cycloalkanes, all of which exhibit simple rings
A molecule containing one or more rings is called a cyclic compound, and a molecule containing two or more rings (either in the same or different ring systems) is termed a polycyclic compound. A molecule containing no rings is called an acyclic or open-chain compound.
A homocycle or homocyclic ring is a ring in which all atoms are of the same chemical element.[1] A heterocycle or heterocyclic ring is a ring containing atoms of at least two different elements, i.e. a non-homocyclic ring.[2] A carbocycle or carbocyclic ring is a homocyclic ring in which all of the atoms are carbon.[3] An important class of carbocycles are alicyclic rings,[4] and an important subclass of these are cycloalkanes.
Rings and ring systems
In common usage the terms "ring" and "ring system" are frequently interchanged, with the appropriate definition depending upon context. Typically a "ring" denotes a simple ring, unless otherwise qualified, as in terms like "polycyclic ring", "fused ring", "spiro ring" and "indole ring", where clearly a polycyclic ring system is intended. Likewise, a "ring system" typically denotes a polycyclic ring system, except in terms like "monocyclic ring system" or "pyridine ring system". To reduce ambiguity, IUPAC's recommendations on organic nomenclature avoid the use of the term "ring" by using phrases such as "monocyclic parent" and "polycyclic ring system".[5]
^IUPAC Chemical Nomenclature and Structure Representation Division (2013). Favre, Henri A.; Powell, Warren H. (eds.). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. IUPAC–RSC. ISBN978-0-85404-182-4.
January 20, 2023
ring, chemistry, chemistry, ring, ambiguous, term, referring, either, simple, cycle, atoms, bonds, molecule, connected, atoms, bonds, which, every, atom, bond, member, cycle, also, called, ring, system, ring, system, that, simple, cycle, called, monocycle, sim. In chemistry a ring is an ambiguous term referring either to a simple cycle of atoms and bonds in a molecule or to a connected set of atoms and bonds in which every atom and bond is a member of a cycle also called a ring system A ring system that is a simple cycle is called a monocycle or simple ring and one that is not a simple cycle is called a polycycle or polycyclic ring system A simple ring contains the same number of sigma bonds as atoms and a polycyclic ring system contains more sigma bonds than atoms Four cycloalkanes all of which exhibit simple rings A molecule containing one or more rings is called a cyclic compound and a molecule containing two or more rings either in the same or different ring systems is termed a polycyclic compound A molecule containing no rings is called an acyclic or open chain compound Contents 1 Homocyclic and heterocyclic rings 2 Rings and ring systems 3 See also 4 ReferencesHomocyclic and heterocyclic rings EditA homocycle or homocyclic ring is a ring in which all atoms are of the same chemical element 1 A heterocycle or heterocyclic ring is a ring containing atoms of at least two different elements i e a non homocyclic ring 2 A carbocycle or carbocyclic ring is a homocyclic ring in which all of the atoms are carbon 3 An important class of carbocycles are alicyclic rings 4 and an important subclass of these are cycloalkanes Rings and ring systems EditIn common usage the terms ring and ring system are frequently interchanged with the appropriate definition depending upon context Typically a ring denotes a simple ring unless otherwise qualified as in terms like polycyclic ring fused ring spiro ring and indole ring where clearly a polycyclic ring system is intended Likewise a ring system typically denotes a polycyclic ring system except in terms like monocyclic ring system or pyridine ring system To reduce ambiguity IUPAC s recommendations on organic nomenclature avoid the use of the term ring by using phrases such as monocyclic parent and polycyclic ring system 5 See also EditCyclic compound Polycyclic compound Heterocyclic compound Bicyclic molecule Spiro compoundReferences Edit IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 1995 Homocyclic compounds doi 10 1351 goldbook H02843 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 1995 Heterocyclic compounds doi 10 1351 goldbook H02798 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 1995 Carbocyclic compounds doi 10 1351 goldbook C00818 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 1995 Alicyclic compounds doi 10 1351 goldbook A00216 IUPAC Chemical Nomenclature and Structure Representation Division 2013 Favre Henri A Powell Warren H eds Nomenclature of Organic Chemistry IUPAC Recommendations and Preferred Names 2013 IUPAC RSC ISBN 978 0 85404 182 4 Retrieved from https en wikipedia org w index php title Ring chemistry amp oldid 1110480595, wikipedia, wiki, book, books, library,
