Modeling the active sites of diiron and dicopper metalloproteins with napthyridine-, phthalazine-, and diethynylbenzene-based ligands

Chapter 1. Bio-Inspired Reactions of Diiron Centers with Dioxygen A variety of biological systems employ carboxylate-bridged diiron centers to achieve substrate oxidation using dioxygen, and numerous small molecule model compounds have been synthesized in order to mimic this chemistry in the absence of a protein scaffold. In this introductory chapter, a brief overview is presented of ligand systems that have been used to prepare diiron complexes, and the subsequent oxidation chemistry of these systems is outlined. Chapter 2. Carboxylate, Phosphodiester, and Hydroxide-Bridged Diiron(II) Complexes with a Sterically Hindered Phthalazine Ligand The synthesis and crystallographic characterization of a series of diiron(II) complexes with a sterically hindered bridging phthalazine ligand are presented. The compounds [Fe₂(Ph₄bdptz)([mu]-O₂CR)₂]²⁺ (R = CH₃ (3); C₂H₅ (4); CH₂Ph (5); t-C₄H₉ (6)), [Fe₂(Ph₄bdptz)([mu]-O₂P(OPh)₂)₂]²⁺ (7), and [Fe₂(Ph₄bdptz) ([mu]-OH)(MeCN)₂]³⁺ (8) were prepared as small molecule models of the catalytic sites in non-heme carboxylate-bridged diiron enzymes. The phenyl rings of Ph4bdptz form a hydrophobic size-constrained pocket in which additional ligands can be accommodated, and they block the possible formation of tetranuclear species. As the steric bulk of the ancillary ligands is increased, the carboxylates shift from a syn, anti to a syn, syn coordination mode, and the Mossbauer spectra of the diiron(II) compounds clearly reflect the symmetry of the iron coordination environment. The oxidation chemistry of the diiron(II) compounds is presented.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Kuzelka, Jane, 1975-

Advisor dc:contributor.advisor

• Stephen J. Lippard.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/30016

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/30016