Organic ligands and nomenclature

Carbene (alkylidene) Carbyne (alkylidyne) Cyclopropenyl (cycto-CgHj) 

The corresponding formulas and names are designated according to this system as follows  

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The need for simple descriptions of complicated organic ligands has led to the evolution of some trivial nomenclature systems, such as those for crown ethers (e.g. 76) 72AG(E)16) and cryptands 73MI10200), which have become quite elaborate 8OMII0200). These systems are intended primarily to indicate topology, and the positions of potential donor atoms, and are not particularly appropriate for general use. 

The second edition of the well-known Red Book, the definitive recommendations of the lUPAC Commission on Nomenclature of Inorganic Chemistry, appeared in Pure Appl. Chem., 28, 1-110 (1971). It is also available separately as a hard-bound reprint. In this edition, the rules for naming organometallic compounds have been completely revised and extended, with introduction of the rj nomenclature for organic ligands. 

For more detailed information on the nomenclature of organic neutral ligands and host-guest systems see Ref. 19. 

The review also pointed out some inconsistent practices in names for organic ligands, the need for agreement of organic ligand names with accepted organic nomenclature practices, and inconsistent practices in the eliding of vowels (e.g., pentammine vs. pentaammine). 

An abbreviation for an organic ligand should be derived from a name consistent with the current rules for the systematic nomenclature of organic compounds.4 (For some ligands a non-systematic name is included in Table VII if it was the source of the abbreviation and if that abbreviation is still commonly used.) New abbreviations should further be constructed according to the following recommendations ... 

For example, dibenzo[18]crown-6 is a crown ether with an 18-membered macrocyclic ring containing six oxygen atoms with two benzo substituents. A more generalised system of nomenclature for such neutral organic ligands was developed by Vogtle and Weber, and later modified by in which... 

This chapter focuses on the process by which T lymphocytes reach the major secondary lymphoid organs of the lung, the lymph nodes. We discuss the migration of the T lymphocyte to lymph nodes, the movement of the T lymphocyte from the vasculature into lymph nodes, and the migration of T lymphocytes within lymph nodes. B lymphocytes and dendritic cells are also discussed. In our discussion we employ the new classification system as presented at the last Keystone Chemokine Symposium. This nomenclature system uses CC, CXC, XC, or CX3C followed by R (for receptor) or L (for ligand) and then a number (5). 

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