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Macrocyclic chemistry: Part I - Characterization of a mixed-valence di-iron complex and synthesis of a new poly-iron complex. Part II - Synthesis, characterization of new diphosphoester macrocyclic polyethers

Author

Son Xuan Hoang, University of the Pacific

Date of Award

2011

Document Type

Dissertation - Pacific Access Restricted

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Pharmaceutical and Chemical Sciences

First Advisor

Larry Spreer

First Committee Member

Charles McCallum

Second Committee Member

Jianhua Ren

Third Committee Member

Liang Xue

Fourth Committee Member

Wade Russu

Abstract

Our research involved two projects: Crown Aza and Crown ether. Crown Aza are compounds that have nitrogens as the hetero-atoms in the macrocycle. In the first aim, the 1 H NMR spectrum of strongly-coupled di-iron complexes shows 5 different conformations, but is unable to identify these conformers. Calculation using Density Functional Theory (DFT) were performed to attempt to quantify these conformers to correlate with the experimental NMR data. The second aim of this study was to utilize the carbonyl functional group of the macrocycles to couple the iron complexes to obtain tetramers or higher oligomers. Visible spectra of the selective reduction of iron mono-keto-macrocycles with boron trifluoride and triethylsilane showed a coupling reaction to form a di-iron complex. A mixture of iron mono-keto-macrocycic with iron diketo-dimacrocycle showed a new species with an intense NIR absorption at 1010 nm. This intense band at 1010 nm is extremely rare in transition metal compounds and is of potential interest in photodynamic therapy. This indicates a new species is formed with a very low energy gap between the ground and excited states. Our second interest is in ionizable crown ethers that have many potential applications from environmental to medical. These macrocyclic poly-ethers contain phosphorous and oxygen atoms which produce a charged moiety in the ring to form a neutral complex with our targeted ions. They are significantly different from all ionizable cyclic poly-ethers in the literature. They vary in ring size from 16-crown-6 to 22-crown-8 using ethylene or propylene linkages between the oxygen atoms. Theoretical calculations revealed these ionizable crown ethers can accommodate ions from 2.6 angstroms to 4.2 angstroms in diameter. Strontium 90 ( 90 Sr 2+ ) is a radioactive product ion from nuclear fission reactions. The Phosphorous containing macrocyclic poly-ether with 2 charges could form complexes with Strontium and are possible candidates for clean-up agents of radioactive materials. The synthesis of ionizable crown ethers is discussed.

Pages

150

ISBN

9781124571065

Recommended Citation

Hoang, Son Xuan. (2011). Macrocyclic chemistry: Part I - Characterization of a mixed-valence di-iron complex and synthesis of a new poly-iron complex. Part II - Synthesis, characterization of new diphosphoester macrocyclic polyethers. University of the Pacific, Dissertation - Pacific Access Restricted. https://scholarlycommons.pacific.edu/uop_etds/157

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