Oxygenextrusion from amidate ligands to generate terminal TaO units under reducing conditions. How to successfully use amidate ligands in dinitrogen coordination chemistry

Autor: Patricia Horrillo-Martinez, Michael D. Fryzuk, Brian O. Patrick, Laurel L. Schafer
Rok vydání: 2012
Předmět:
Zdroj: Dalton Trans.. 41:1609-1616
ISSN: 1477-9234
1477-9226
DOI: 10.1039/c1dt11595b
Popis: A series of mixed Cp* amidate tantalum complexes Cp*Ta(RNC(O)R')X(3) (where R = Me(2)C(6)H(3), (i)Pr, R' = (t)Bu, Ph, X = Cl, Me) have been prepared via salt metathesis and their fundamental reactivities under reducing conditions have been explored. Reaction of the tantalum chloro precursors with potassium graphite under N(2) or Ar leads to the stereoselective formation of the terminal tantalum oxo species, Cp*Ta=O(η(2)-RN=CR')Cl. This represents the formal extrusion of oxygen from the amidate ligand to the reduced tantalum center and is accompanied by the formation of the iminoacyl fragment bound to Ta(v). Amidate dinitrogen complexes, [Cp*TaCl(RNC(O)(t)Bu)](2)(μ-N(2)) (where R = Me(2)C(6)H(3), (i)Pr) were synthesized via salt metathesis from the known [Cp*TaCl(2)](2)(μ-N(2)) precursor, establishing that amidate ligands can support dinitrogen complexes, but not the reduction process often necessary for their synthesis.
Databáze: OpenAIRE