What is "trisoxazolinylborate"

Tris(oxazolinyl)borate compounds are a class of tridentate ligands; often abbreviated To, where R is the substituent on the oxazoline ring. Most commonly the substituent is either a methyl, propyl, tert-butyl or hydrogen. The formation of anionic boron backbone with addition of a phenyl group on boron allows the ligand to strongly bind to the metal center. It results in a more robust complex.

Tris(oxazolinyl)borates can be characterised as scorpionate ligands and may be compared to tris(pyrazolyl)borate and trisoxazoline ligands. In bulky pyrazolylborate (Tp) derivatives, isomerization may occur via 1,2-shifts; additionally B–N bond cleavage is a common decomposition pathways for the Tp ligands. The oxazoline-based ligands with B-C linkages avoid these decomposition problems.