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167:. Tridentate ligands usually bind via two kinds of connectivity, called "mer" and "fac." "fac" stands for facial, the donor atoms are arranged on a triangle around one face of the octahedron. "mer" stands for meridian, where the donor atoms are stretched out around one half of the octahedron. Cyclic tridentate ligands such as
185:(abbreviated trien). For different central metal geometries there can be different numbers of isomers depending on the ligand's topology and the geometry of the metal center. For octahedral metals, the linear tetradentate trien can bind via three geometries. Tripodal tetradentate ligands, e.g.
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Relationship between "linear" bi-, tri- and tetradentate ligands (red) bound to an octahedral metal center. The structures marked with * are chiral owing to the backbone of the tetradentate ligand.
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249:. Polydentate ligands such as hexa- or octadentate ligands tend to bind metal ions more strongly than ligands of lower denticity, primarily due to entropic factors.
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and classified by their denticity. Some atoms cannot form the maximum possible number of bonds a ligand could make. In that case one or more
228:(DTPA) are octadentate. They are particularly useful for binding lanthanide ions, which typically have coordination numbers greater than 6.
68:. In many cases, only one atom in the ligand binds to the metal, so the denticity equals one, and the ligand is said to be
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In general, the stability of a metal complex correlates with the denticity of the ligands, which can be attributed to the
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because hapticity refers exclusively to ligands where the coordinating atoms are contiguous. In these cases the
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are a quantitative measure to assess the thermodynamic stability of coordination complexes.
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Zelewsky, A. "Stereochemistry of Coordination Compounds" John Wiley: Chichester, 1995.
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Number of atoms in a ligand that bond to the central atom of a coordination complex
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Bidentate (also called didentate) ligands bind with two atoms, an example being
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471:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
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of the ligand are unused. Such sites can be used to form a bond with another
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describes an EDTA ligand that coordinates through 6 non-contiguous atoms.
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bind with five atoms, an example being ethylenediaminetriacetic acid.
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Ligands of denticity greater than 6 are well known. The ligands
84:. The denticity of a ligand is described with the Greek letter
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76:). Ligands with more than one bonded atom are called
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1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate
193:ligands are tetradentative, an example being the
153:, which features two different bidentate ligands.
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217:(although it can bind in a tetradentate manner).
181:bind with four donor atoms, an example being
383:η (eta or hapto) in inorganic nomenclature
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163:bind with three atoms, an example being
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56: 'tooth') refers to the number of
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213:bind with six atoms, an example being
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468:Compendium of Chemical Terminology
436:Compendium of Chemical Terminology
407:Compendium of Chemical Terminology
378:Compendium of Chemical Terminology
346:Compendium of Chemical Terminology
300:Compendium of Chemical Terminology
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277:2.4MB PDF - Slide 3 on denticity
226:diethylene triamine pentaacetate
149:Structure of the pharmaceutical
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275:EDTA chelation lecture notes.
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95:Denticity is different from
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103:('eta') notation is used.
88:('kappa'). For example, κ-
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443:in inorganic nomenclature
353:in inorganic nomenclature
175:bind in a facial manner.
119:Polydentate ligands are
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452:10.1351/goldbook.M03659
420:10.1351/goldbook.B00741
391:10.1351/goldbook.H01881
362:10.1351/goldbook.K03366
313:10.1351/goldbook.D01594
187:tris(2-aminoethyl)amine
499:Coordination chemistry
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42:coordination chemistry
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205:Pentadentate ligands
183:triethylenetetramine
179:Tetradentate ligands
66:coordination complex
251:Stability constants
241:Stability constants
211:Hexadentate ligands
36:monodentate ligands
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161:Tridentate ligands
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72:(sometimes called
60:groups in a given
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111:('mu') notation.
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509:Chelating agents
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224:(DOTA) and
191:macrocyclic
165:terpyridine
151:Oxaliplatin
78:polydentate
70:monodentate
493:Categories
351:κ (kappa)
329:047195599X
282:References
74:unidentate
48:(from
473:chelation
305:denticity
195:porphyrin
97:hapticity
46:denticity
34:Atom with
18:Bidentate
441:µ- (mu)
257:See also
173:9-ane-S3
107:use the
263:Chelate
115:Classes
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62:ligand
54:dentis
463:IUPAC
431:IUPAC
402:IUPAC
373:IUPAC
341:IUPAC
295:IUPAC
58:donor
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50:Latin
325:ISBN
215:EDTA
199:heme
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169:TACN
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109:μ
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86:κ
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