Date of Award

Spring 2013

Project Type


Program or Major


Degree Name

Master of Science

First Advisor

Samuel Pazicni


Heme-thiolate proteins are known to have hydrogen bond donors proximal to the axial thiolate ligand. The specific roles of these conserved H-bond donors have not yet been elucidated. However, various sources agree upon the positive influence that increased X-H···S interactions have on protein redox potentials. For example, synthetic modeling studies of the cytochromes P450 show similar positive shifts in potential in iron-porphyrin-thiolate model systems. The ligands used in modeling the H-bonding interactions in the P450 cytochromes included a series of 2,6-substituted thiophenols, -S(2,6-(CX3CONH)2C6H3), where X = H, F, CH3. The current synthetic route to these ligands is vague and employs materials that are no longer commercially available. Seeking a new synthetic route to the precursor to this ligand series, bis(2,6- diaminophenyl)disulfide, 2,6-dinitrophenylsulfonyl chloride (14) has been synthesized and characterized by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR). The steric contributions of these bulky ligands may have an effect on the redox potential and Fe-S bond length of the heme-thiolate complexes. This new idea prompted the synthesis of a putative precursor to the nearly isosteric bis-ester ligand series, -S-(2,6- (CX3COO) 2C6H3), where X is as specified above. Compound 18 and its intermediates were characterized by NMR.