Tp Class
The tris(pyrazolyl)borate ligand is often known as Tp to many inorganic chemists - using different pyrazoles substituted in the 3,4, and 5 positions, a range of different ligands can be formed. In this article we will group all the trispyrazolylborates together.
These compounds are usually synthesized by reacting pyrazole with alkali-metal borohydrides, such as sodium borohydride NaBH4, under reflux. H2 is evolved as the borohydride is sequentially converted first to pyrazolylborate, then to bis(pyrazolyl)borate, and finally to tris(pyrazolyl)borate . Bulky pyrazolyl borates can be prepared from 3,5-disubstituted pyrazoles, such as the dimethyl derivative. These bulky pyrazolyl borates have proven especially valuable in the preparation of catalysts and models for enzyme active sites. Utilizing scorpionate ligands in the syntheses of metal catalysts may allow simpler and more accurate methods to be developed. ligands allow for good shielding of the bound metal while strong sigma bonds between the nitrogens and the metal stabilize the metal; these attributes help scorpionate compounds with creating highly symmetrical supramolecular silver complexes and olefin polymerization (with the compound hydrotris(pyrazolyl) borate Mn).
Read more about this topic: Scorpionate Ligand
Famous quotes containing the word class:
“But you must know the class of sweet women—who are always so happy to declare “they have all the rights they want”; “they are perfectly willing to let their husbands vote for them”Mare and always have been numerous, though it is an occasion for thankfulness that they are becoming less so.”
—Eliza “Mother” Stewart (1816–1908)