Synthesis, Characterization And Electrochemical Investigation Of Novel Diiron Model Complexes Of [FeFe]-Hydrogenase

In this dessertation, ligands of the moiety of1,8-naphthalenedisulfide were designed and synthesised. Reaction of the ligands with Fe3(CO)12plus post-reaction modification produced10diiron hexacarbonyl model complexes as the mimics of [FeFe]-hydrogenase. These model complexes were fully charcterised, and the electron transfer mechanisms of the reduction process of the complexes were also inverstigated.Ligands derived from naphthalene-1,8-dithiolate were2-formylnaphthalene-1,8-disulfide (2a),4-formylnaphthalene-1,8-disulfide2b and naphthalene-1,8-dithiolate-2-carboxylic acid (8). Rection of these ligands with [Fe3(CO)12] produced diiron complexes3a,3b and9, respectrively. Complexes4a and4b were synthesized by reducing the aldehyde group into hydroxymethyl group. The hydroxyl group could react further to form complexes5a,5b,6a,6b and7a, respectively. These complexes were fully characterized by FTIR, UV-vis,1H NMR. The structures of some of the diiron complexes (3a,3b,4b,5b,6a, and7a) were also crystallographically determined, and the electro-catalytic reduction of proton by these compounds was studied in details.7a was synthesised to act as an electrochemical probe to investigate the electron transfer of the diiron complexes. Electrochemical investigations, chemical reduction and DFT-calculation of7a revealed that in the ECE (E for electrochemical reaction and C for chemical reaction) mechanism with potential inversion adopted by the complex, the redox potential of the second process is nearly identical to that of the first one.