Reaction Chemistry of Silver(I) Trifluoromethanesulfonate Complexes of Nitrogen-Confused C‑Scorpionates
journal contribution
posted on 2018-01-22, 23:10 authored by James R. Gardinier, Kristin J. Meise, Fathiya Jahan, Sergey V. LindemanTwo new C-scorpionate
ligands with a bis(3,5-dimethylpyrazol-1-yl)methyl group bound to
the 3 position of either an N-tosyl (TsL*) or an N–H pyrazole (HL*) ring have been prepared.
The silver(I) complexes of these new ligands and the two previously
reported analogous ligands with unsubstituted bis(pyrazol-1-yl)methyl
groups (TsL and HL) in both 1:1 and 2:1 ligand/metal
ratios were investigated to explore the effects of ligand sterics
on their physical and chemical properties. The structurally characterized
derivatives of the type [Ag(L)2](OTf) are four-coordinate,
where the confused pyrazolyl is not bound to the metal. On the other
hand, three 1:1 complexes [Ag(L)](OTf) had all pyrazolyls bound, while
the μ–κ1,κ1-TsL derivative had an unbound confused pyrazolyl. The molecularity
of the latter four ranged from polymeric to dimeric to monomeric in
the solid with increasing steric bulk of the ligand. The utility of
these complexes in stoichiometric ligand-transfer reactions and in
styrene aziridination was demonstrated. Thus, tricarbonylmanganese(I)
complexes were prepared as kinetically inert models for comparative
solution diffusion NMR studies. Also, [Fe(HL)2](OTf)2 was prepared for similar reasons and to compare
the effects of anion on spin-crossover properties.
