Chemistry and Biochemistry
Dithiolenes, Nickel dithiolene, Molybdenum dithiolene, Pyran
A new class of dithiolene ligand containing a pyran ring that mimics a biologically important MPT (molybdopterin) have been proposed and the key reactions have been established to synthesize this ligand. Along with that, new dithiolene complexes of nickel [Ni(dt)2]n, where dt=dithiolene ligand, n=charge, have been synthesized and characterized by several spectroscopic techniques. A characteristic low energy charge transfer band in UV-visible spectra is found to be the good indicator of purity as well as the anionic states of the nickel complexes.
A ligand exchange reaction using neutral nickel complexes and molybdenum carbonyl complexes has been utilized to synthesize (LN2)MoO(dt) type of complexes, where LN2 = nitrogen based bis chelating ligand, to mimic the active site of mononuclear molybdoenzymes. We observed a ligand exchange reaction to generate a Mo(dt)3 type species but no target complexes were observed under the conditions we employed. Another set of reactions involving complexes having higher oxidation state of Mo and LN2 ligands showed promising results. 1H NMR, IR Spectroscopy and Mass spectrometry results showed that we have synthesized complexes of type (LN2)MoO(dt) and (LN2)Mo(CO)2(dt), where LN2 = 1,10-Phenanthroline.
Nigam, A. (2004). Chemistry of Dithiolenes and Their Nickel and Molybdenum Complexes (Master's thesis, Duquesne University). Retrieved from https://dsc.duq.edu/etd/981