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156:. 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
174:(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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238:. 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
217:(DTPA) are octadentate. They are particularly useful for binding lanthanide ions, which typically have coordination numbers greater than 6.
57:. 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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460:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
428:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
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370:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
338:, 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
73:. The denticity of a ligand is described with the Greek letter
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65:). Ligands with more than one bonded atom are called
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1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate
182:ligands are tetradentative, an example being the
142:, which features two different bidentate ligands.
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206:(although it can bind in a tetradentate manner).
170:bind with four donor atoms, an example being
372:η (eta or hapto) in inorganic nomenclature
53:that bind to the central metal atom in a
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152:bind with three atoms, an example being
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45: 'tooth') refers to the number of
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202:bind with six atoms, an example being
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457:Compendium of Chemical Terminology
425:Compendium of Chemical Terminology
396:Compendium of Chemical Terminology
367:Compendium of Chemical Terminology
335:Compendium of Chemical Terminology
289:Compendium of Chemical Terminology
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266:2.4MB PDF - Slide 3 on denticity
215:diethylene triamine pentaacetate
138:Structure of the pharmaceutical
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264:EDTA chelation lecture notes.
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84:Denticity is different from
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92:('eta') notation is used.
77:('kappa'). For example, κ-
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432:in inorganic nomenclature
342:in inorganic nomenclature
164:bind in a facial manner.
108:Polydentate ligands are
470:10.1351/goldbook.C01012
441:10.1351/goldbook.M03659
409:10.1351/goldbook.B00741
380:10.1351/goldbook.H01881
351:10.1351/goldbook.K03366
302:10.1351/goldbook.D01594
176:tris(2-aminoethyl)amine
488:Coordination chemistry
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31:coordination chemistry
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194:Pentadentate ligands
172:triethylenetetramine
168:Tetradentate ligands
55:coordination complex
240:Stability constants
230:Stability constants
200:Hexadentate ligands
25:monodentate ligands
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150:Tridentate ligands
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61:(sometimes called
49:groups in a given
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100:('mu') notation.
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213:(DOTA) and
180:macrocyclic
154:terpyridine
140:Oxaliplatin
67:polydentate
59:monodentate
482:Categories
340:κ (kappa)
318:047195599X
271:References
63:unidentate
37:(from
462:chelation
294:denticity
184:porphyrin
86:hapticity
35:denticity
23:Atom with
430:µ- (mu)
246:See also
162:9-ane-S3
96:use the
252:Chelate
104:Classes
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51:ligand
43:dentis
452:IUPAC
420:IUPAC
391:IUPAC
362:IUPAC
330:IUPAC
284:IUPAC
47:donor
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39:Latin
314:ISBN
204:EDTA
188:heme
160:and
158:TACN
79:EDTA
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98:μ
90:η
75:κ
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