Characterization of tetranuclear manganese complexes and thermochromic copper(II) and nickel(II) complexes

Two different projects are described. In the first, the magnetic and electronic properties of four tetranuclear manganese complexes that are potential models for the oxygen evolving complex of photosystem II are examined. The complexes, based upon x-ray crystallography are cubane like structures containing a single manganese ion with a +4 oxidation state and three manganese ions with an oxidation state of +3. Based upon magnetic susceptibility measurements and high magnetization experiments the complexes were found to have an S = 9/1 ground state. This is the result of an antiferromagnetic interaction between Mn(III) and Mn(IV) ions and a ferromagnetic interaction between Mn(III) ions. Further characterization comes from theoretical X-alpha LCAO calculations on one of the complexes. These calculations correctly predicted the ground state and temperature dependence of the effective magnetic moment. Based upon these results, a model describing the effects of spin polarization on ground and excited state stability.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry, Inorganic

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Schmitt, Edward Albert

Contributors dc:contributor

• Hendrickson, David N.

• Chemistry, Inorganic
• Chemistry, Physical

Statement dc:rights

• Copyright 1995 Schmitt, Edward Albert

Language dc:language

eng

Identifier

AAI9624486
(UMI)AAI9624486

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/23650