Iron(II) complexes bearing anilido-imine ligands: Synthesis and catalysis on ATRP of methyl methacrylate

Reactions of the ortho-C6H4(NHAr)-(CHNAr) with nBuLi and subsequent addition of FeCl2 afford the anilido-aldimine Fe(II) complexes [(ArNCHC6H4-NAr)Fe]2(μ-Cl)2 (Ar = 2,6-Me2C6H3 (1a); Ar = 2,6-Et2C6H3 (1b)), and (ArNCHC6H4-NAr)Fe(μ-Cl)2Li(THF)2 (Ar = 2,6-iPr2C6H3 (1c)). Similarly, reactions of the 2-(ArNC(H))C6H4-HNC9H6N with nBuLi and FeCl2 give the N,N,N-tridentate iron complexes {[2-(ArNC(H))C6H4-NC9H6N]Fe}2(μ-Cl)2 (Ar = 2,6-Me2C6H3 (2a), 2,6-Et2C6H3 (2b), and 2,6-iPr2C6H3 (2c)). The X-ray diffraction analysis reveals that 1a and 1b are dimeric complexes and 1c is hetero-binuclear complex. Fe(II) atoms in these complexes are all in a distorted tetrahedral geometry. Complex 2c was confirmed to be a dimeric complex with the iron atom in a trigonal bipyramidal geometry. Complexes 1a–1c show moderate activities in ATRP of MMA in the presence of benzyl chloride (BnCl). While complexes 2a–2c are inert under the same condition.

Several Fe(II) complexes supported by anilindo-imine and quinolinyl anilindo-imine ligands were synthesized and tested in iron mediated ATRP polymerization of MMA.Figure optionsDownload as PowerPoint slide