Ligand-Centered Redox Activity: Redox Properties of 3d Transition Metal Ions Ligated by the Weak-Field Tris(pyrrolyl)ethane Trianion

DSpace/Manakin Repository

Ligand-Centered Redox Activity: Redox Properties of 3d Transition Metal Ions Ligated by the Weak-Field Tris(pyrrolyl)ethane Trianion

Citable link to this page

 

 
Title: Ligand-Centered Redox Activity: Redox Properties of 3d Transition Metal Ions Ligated by the Weak-Field Tris(pyrrolyl)ethane Trianion
Author: Betley, Theodore A; Sazama, Graham Thomas

Note: Order does not necessarily reflect citation order of authors.

Citation: Sazama, Graham T., and Theodore A. Betley. 2010. Ligand-centered redox activity: Redox properties of 3d transition metal ions ligated by the weak-field tris(pyrrolyl)ethane trianion. Inorganic Chemistry 49(5): 2512–2524.
Access Status: Full text of the requested work is not available in DASH at this time (“dark deposit”). For more information on dark deposits, see our FAQ.
Full Text & Related Files:
Abstract: First-row transition metal complexes of the tris(pyrrolyl)ethane (tpe) trianion have been prepared. The tpe ligand was found to coordinate in a uniform η1,η1,η1-coordination mode to the divalent metal series as revealed by X-ray diffraction studies. Magnetic and structural characterization for complexes of the type [(tpe)MII(py)][Li(THF)4] (M: Mn, Fe, Co, Ni) reveal each divalent ion to be high-spin and have a distorted trigonal-monopyramidal geometry in the solid state. The pyridine ligand binds significantly canted from the molecular C3 axis due to a stabilizing π-stacking interaction with a ligand mesityl substituent. Cyclic voltammetry on the [(tpe)MII(py)]- series reveals a common irreversible oxidation pathway that is entirely ligand-based, invariant to the divalent metal bound. This latter observation indicates that fully populated ligand-based orbitals from the tpe construct are energetically most accessible in the electrochemical experiments, akin to their dipyrromethane analogues. Chemical oxidation of [(tpe)FeII(py)]- yields a product in which the ligand has dissociated one pyrrole (following tpe oxidation and H-atom abstraction) and binds a second equivalent of pyridine to form the neutral, tetrahedral FeII species (κ2-tpe)Fe(py)2. Similarly, chemical oxidation of the Zn(II) analogue shows evidence for tpe oxidation by electron paramagnetic resonance spectroscopy (77 K, toluene glass) with an isotropic signal for the organic radical at g = 2.002. Density functional theory analysis on this family of complexes reveals that the highest lying molecular orbitals are completely ligand-based, corroborating our proposed electronic structure assignment.
Published Version: doi:10.1021/ic100028y
Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:32116875
Downloads of this work:

Show full Dublin Core record

This item appears in the following Collection(s)

 
 

Search DASH


Advanced Search
 
 

Submitters