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 NaBH, under reflux.  H is evolved as the borohydride is sequentially converted first to pyrazolylborate [HB(CNH)], then to bis(pyrazolyl)borate [HB(CNH)], and finally to tris(pyrazolyl)borate [HB(CNH)]. 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).