Search results
Results from the WOW.Com Content Network
Ethylenediamine ligand chelating to a metal with two bonds Cu 2+ complexes with nonchelating methylamine (left) and chelating ethylenediamine (right) ligands. The chelate effect is the greater affinity of chelating ligands for a metal ion than that of similar nonchelating (monodentate) ligands for the same metal.
The chelate effect increases as the number of chelate rings increases. For example, the complex [Ni(dien) 2)] 2+ is more stable than the complex [Ni(en) 3)] 2+; both complexes are octahedral with six nitrogen atoms around the nickel ion, but dien (diethylenetriamine, 1,4,7-triazaheptane) is a tridentate ligand and en is bidentate. The number of ...
This ligand–metal–ligand geometric parameter is used to classify chelating ligands, including those in organometallic complexes. It is most often discussed in terms of catalysis , as changes in bite angle can affect not just the activity and selectivity of a catalytic reaction but even allow alternative reaction pathways to become accessible.
Most commonly, amino acids coordinate to metal ions as N,O bidentate ligands, utilizing the amino group and the carboxylate. They are "L-X" ligands. A five-membered chelate ring is formed. The chelate ring is only slightly ruffled at the sp 3-hybridized carbon and nitrogen centers.
Ethylenediamine is a well-known bidentate chelating ligand for coordination compounds, with the two nitrogen atoms donating their lone pairs of electrons when ethylenediamine acts as a ligand. It is often abbreviated "en" in inorganic chemistry. The complex [Co(en) 3] 3+ is a well studied example. Schiff base ligands easily form from ...
Some are useful commercially, but the topic has attracted regular scholarly scrutiny. Oxalate (C 2 O 4 2-) is a kind of dicarboxylate ligand. [1] As a small, symmetrical dinegative ion, oxalate commonly forms five-membered MO 2 C 2 chelate rings. Mixed ligand complexes are known, e.g., [Co(C 2 O 4)(NH 3) 4] κ+. [2]
Synthesis of a diphosphine pincer ligand. To generate the metal complex, two common routes are employed. One is a simple oxidative addition of the ipso-C-X bond where X = Br, I to a metal centre, often a M(0) (M = Pd, Mo, Fe, Ru, Ni, Pt) though other metal complexes with higher oxidation states available can also be used (e.g. Rh(COD)Cl 2). [11 ...
A common diphosphine ligand is dppe, which forms a five-membered chelate ring with most metals. Some diphosphines, such as the extraordinary case of t Bu 2 P(CH 2 ) 10 P t Bu 2 , give macrocyclic complexes with as many as 72 atoms in a ring.