Syntheses and Electronic Structure of Bimetallic Complexes Containing a Flexible Redox-Active Bridging Ligand

Abstract

The new ligand L(1), 1-N,1-N-bis(pyridine-2-ylmethyl)-3-N-(pyridine-2-ylmethylidene)benzene-1,3-diamine, was synthesized as a platform for the study of bimetallic complexes containing redox-active ligands. The asymmetric L(1) contains a redox-active α-iminopyridine unit bridged to redox-inert bis(2-pyridylmethyl)amino counterpart and offers two distinct coordination sites. The coordination chemistry of L(1) with Fe, Cu, and Zn was examined. Reaction with zinc afforded the asymmetric binuclear complex [(L(1))Zn(2)Cl(4)] (1), whereas the symmetric [(L(1))(2)Fe(2)(OTf)(2)](OTf)(2) (2) and [(L(1))(2)Cu(2)](OTf)(4) (3) were isolated in reactions with iron and copper. Both metal- and ligand-centered redox processes are available to the series of metal compounds. EPR and Mössbauer spectroscopy and magnetic susceptibility studies establish that both 2 and 3 are paramagnetic; the vanishingly small ferromagnetic interaction produces decoupled high-spin Fe(II) (S = 2) ions in 2. DFT calculations provide further insight into the nature of the exchange interactions in the dimeric systems.

C‐H Oxidation by a Diiron Complex with Facially Opposing Active Sites

“…The synthesis and characterization of 1′ was previously described . The homologous [(L 1 ) 2 Fe 2 (CH 3 CN) 2 ](PF 6 ) 4 was synthesized in the reaction of L 1 with [Fe(CH 3 CN) 6 ](PF 6 ) 2 .…”

“…We recently reported the synthesis of a bimetallic iron complex, [(L 1 ) 2 Fe 2 (OTf) 2 ](OTf) 2 (Scheme , 1′ , Y = OTf), coordinated by an asymmetric, redox‐active ligand . We present here a newly isolated sister complex, [(L 1 ) 2 Fe 2 (CH 3 CN) 2 ](PF 6 ) 4 (Scheme , 1 , Y = CH 3 CN and Figure ), and the oxidative activity of this compound toward hydrocarbons.…”

Experimental and theoretical evaluation of N, N-Bis(2-pyridylmethyl)aniline as a novel corrosion inhibitor for mild steel in hydrochloric acid

“…1), was synthesized according to a previously reported literature [19]. (10 mmol) in N, N-diisopropylethylamine stirred well under N 2 atmosphere.…”

“…E HOMO is associated with the electron donating ability of a molecule, whereas E LUMO signifies the electron receiving tendency of a molecule [19]. Accordingly, the higher value of E HOMO , the stronger ability of the molecule to donate electrons while the lower E LUMO is, the greater ability of the molecule to accept electrons from the metal [24,25].…”

“…The condensed Fukui functions can be calculated as: (19) where q k is the gross charge of atom k in the molecule. q k (N+1), q k (N) and q k (N-1) correspond to the charge values of atom k for anion, neutral and cation, respectively.…”