1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

ing does not allow for the possibility of an O-N bidentate coordination pocket like in V-
9 there are interesting potential oxidations states including the possibility of a zwitterion.
This project has only been taken as far as the HCl salt (similar to the direct precursor for
V-9) and while there has been some preliminary work put towards the formation of the
dichloride salt not enough evidence has been collected to verify that this reaction has
been completed successfully. The following will discuss the characterization data
obtained for the dinitro species as well as the subsequent HCl salt.
5.4.2 Synthesis
The first step of this reaction was originally carried out in an early attempt at
obtaining V-11. After attempting to replicated the synthesis outlined in the original
reference for this compound, 8
several other methods of nitration were attempted
including the harsh conditions involving concentrated sulfuric acid as the solvent with the
addition of concentrated nitric acid as the nitrating agent. When the 1,2-naphthoquinone
was first dissolved in sulfuric acid at 0 °C the orange/brown solid gave way to a dark blue
solution. Then a small amount of concentrated nitric acid, consistent with approximately
2 equivalents of NO 2 was added while the reaction mixture was held at 0 °C. This
resulted in a slight red tinge emerging in the reaction mixture which was then warmed to
room temperature and then further heated to approximately 60-70 °C for about 45
minutes. After this time the solution was clear and dark red and it was allowed to cool to
room temperature. It was then poured on crushed ice resulting in a large amount of pale
orange solid crashing out of the solution (V-15). This was filtered and washed with a
small amount of water followed by diethyl ether to ensure that the compound would be
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