| Bioinorganic model chemists seek to synthesize compounds that mimic the coordination environment and reactivity that are observed at the active sites of metallo-enzymes. The research presented here focuses on several ligand systems, containing either nitrogen or sulfur, and their potential use in complexes with biologically relevant metals. Compounds are characterized using an array of techniques including UV-visible spectroscopy, nuclear magnetic resonance spectroscopy (NMR), Infrared spectroscopy (IR), electron paramagnetic resonance spectroscopy (EPR), fluorescence spectroscopy, elemental analysis (EA), single crystal X-ray diffraction, temperature dependent magnetic susceptibility, and cyclic voltammetry (CV).; To model the ubiquitous histidine coordination environment found in many enzymes, diphenyldipyrazolylmethane (DPDPM) is synthesized. This ligand contains two pyrazole moieties for metal coordination. Mononuclear complexes with copper, zinc and iron reveal interesting aspects of its coordination chemistry and reactivity. Dinuclear, oxalato-bridged complexes employing DPDPM are also studied to explore Cu(II)-Cu(II) magnetic communication. Attempts are made to correlate the degree of antiferromagnetic coupling with structural parameters.; In addition, the spectroscopic properties of the macrocyclic ligand N-confused tetraphenylporphyrin (H2NCTPP), an isomer of porphyrin, are explored. The periphery of the macrocycle is altered, using electron withdrawing or electron donating groups, to study the effect on absorption and fluorescence spectra. Both the internal and the external tautomers, depending on solvent conditions, are discussed, and the synthetic crude yields and purification techniques are provided.; Finally, cysteine-based ligands are synthesized and characterized. A three-step synthetic protection protocol was developed to produce ligands with only the thiol group available for metal binding. Interestingly, racemic mixtures of D- and L-cysteine are produced under the conditions of the reactions. The single crystal X-ray structures are provided as rare examples of crystalline cysteine ligands. |
