Degree Type

Dissertation

Date of Award

2018

Degree Name

Doctor of Philosophy

Department

Chemistry

Major

Inorganic Chemistry

First Advisor

Aaron D. Sadow

Abstract

Our group previously developed the synthesis of main group Zn(II) and Mg(II) complexes supported by the ToM (tris(4,4-dimethyl-2-oxazolinyl)phenylborate) ligand. The reactivity of these main group oxazolinyl based complexes in oxygenation, hydrosilylation, and hydroboration reactions provided motivation for studying the reactivity of late first-row transition metals. This thesis focuses on the synthesis, characterization, and reactivity of late transition metal complexes based on iron, nickel and cobalt containing ToM as the ancillary as well as the synthesis and characterization of other paramagnetic molecules .

Salt metathesis reaction of TlToM with CoCl2THF (THF = tetrahydrofuran), FeBr2, or NiCl2DME (DME = dimethoxyethane) at room temperature in THF afforded ToMCoCl, ToMFeBr, and ToMNiCl, respectively. ToMCoCl, ToMFeBr, and ToMNiCl react with NaOAc to form the acetate complexes ToMCoOAc, ToMFeOAc, and ToMNiOAc, respectively. ToMCoOAc was studied in the oxidation of cyclohexane using meta-chloroperoxybenzoic acid (mCPBA) as the oxidant and found to selectively catalyze the formation of cyclohexanol over the over-oxidized products of cyclohexanone and ε–caprolactone.

Reaction of ToMCoCl, ToMFeBr, and ToMNiCl with alkyllithiums or potassium benzyl were attempted as a route to organometallic complexes. The nickel(II) alkyls were not identified under the reaction conditions attempted; however, ToMCoR (R = Me, Et, nBu, CH2SiMe3, Bn, and Ph) and ToMFeR (R = Bn) compounds were found to be isolable.

ToMCoR (R = Me, Et, nBu, CH2SiMe3, Bn, and Ph) complexes react with CO followed by O2 to form the carboxylate compounds ToMCoO2CR (R = Me, Et, nBu, CH2SiMe3, Bn, and Ph). The direct insertion of CO2 into the Co-R bond is determined to be much slower, requiring several days to weeks depending upon the R group. ToMFeBn reacts with CO to form ToMFe{C(O)Bn}(CO)2, but sequential addition of O2 does not provide the corresponding carboxylate compound suggesting the oxidative carbonylation reactivity is unique to cobalt. Lastly, the expertise gained from the synthesis and characterization of paramagnetic complexes provided guidance for the synthesis and characterization of deuterated biradicals to be used as polarizing agents in dynamic nuclear polarization (DNP).

DOI

https://doi.org/10.31274/etd-180810-6073

Copyright Owner

Regina Reinig

Language

en

File Format

application/pdf

File Size

155 pages

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