Formation of stable iron/cobalt NHC complexes via unexpected ring opening and in situ generation of a tridentate ligand

摘要

The reactions of FeCl _2 and CoCl _2 with a bistriazolium salt yields the NHC complexes [Fe ~III(L ~1) _2]I·H _2O, [Fe ~III(L ~2) _2]PF _6·CH _3CN and [Co ~III(L ~1) _2]I·0.5CH _3CN, through an unusual ring opening of one of the triazoyl rings, which leads to the formation of C,N,O tridentate ligands L ~1 or L ~2. Furthermore, a Fe(ii) species [Fe ~II(L ~1) _2]·CH _2Cl _2 was also obtained.