Triazole tridentate chelating

Mononuclear Fe(ll) Spin Crossover Compounds of Tridentate Chelating 1,2,4-Triazole Derivatives... 

A range of tridentate click ligands have been synthesized and characterized. While the majority of these ligands contain two or three 1,4-disubstituted-1,2,3-triazole units, there are a few examples of tridentate chelators that contain one 1,2,3-triazole unit. 

Adolfsson et al. have used related amino acid-derived mOTio-l,4-disubstituted-1,2,3-triazole containing tridentate chelators, 86, as ligands in ATH reactions (Fig. 19) [190]. The authors screened a family of ligands with different steric and electronic properties in the Rh(I)-catalyzed ATH of acetophenone to 1-phenyethanol and showed that the use of these click catalysts led to good conversion (62-79%) and high ee (71-93%). 

The perfluoro-1,2,4-triazoles are known to be effective ligands. For instance, a number of charge neutral Os(II) pyridyl-l,2,4-triazolate complexes with either bis(diphenylphosphino)methane 93 or ct>l,2-bis(diphenylphosphino)ethene 94 chelates were synthesized, and their structural, electrochemical, photophysical properties and thermodynamic relationships were established [89, 90], Chi, Carty et al. synthesized 6-(3-trifluoromethyl-l,2,4-triazolyl)-2,2 -bipyridine and built up on this basis tridentate 6-azolyl-2,2 -bipyridine chelate complex compounds of Ga and In 95 [91],... 

---