The synthesis and characterization of dithiolenes with intense electronic transitions in the Near-IR region near 1.5 microns

Date of Completion

January 1988


Physics, Optics




One of the most unusual properties of dithiolene complexes is their intense electronic transition in the VIS and Near-IR regions of the electromagnetic spectrum. To investigate the possibility of utilizing dithiolenes as dyes for the purpose of Q-switching NIR lasers, this work concerns the synthesis and characterization of new dithiolenes with intense absorption in the region between 1.3 and 1.5 $\mu$. The first task was to define the design of new ligand systems which incorporate several structural features necessary to shift the adsorption band into the lower energy range. An analysis of these structural features suggests the dithiolenes with amino-substituted acenaphthene and phenanthrene ligands as the best choice to reach 1.5$\mu$. Therefore, the target compounds of this thesis are bis(3,6-bis-diethylaminophenanthrene-9,10-dithiolato)nickel, bis(1,12-diethyl-1,2,3,4,9,10,11,12-octahydro-1,12-diazapentaphene-6,7-dithiolato)nickel and bis(1,4,9,12-tetraethyl-1,2,3,4,9,10,11,12-octahydro-1,4,9,12-tetraazapentaphene-6,7-dithiolato)nickel. The synthesis of these materials was accomplished. It was also deduced from the experimental results that this approach is reaching the limits to which donor-substituted benzenoid aromatics can be expected to shift the low-energy dithiolene absorption. ^