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

In Figure 2-1a, the nickel complex has a very strong peak at 1471 cm -1 which is most
likely a result of a peak from the metal-containing starting material which has shifted
slightly. The other labelled peaks 1421, 831, 647 and 427 cm -1 can be seen in the
spectrum for the radical but barely rise above the baseline in the coordination complex.
In Figure 2-1b, the spectrum for the manganese complex has a shoulder appearing in the
same region as the peak at 1471 cm -1 from the previous example. Also, once again, there
are low intensity peaks in the coordination complex that can be attributed to the radical at
824, 650 and 635 cm -1 .
The infrared spectra for the two DTDA zinc coordination species are fairly similar to
one another as the binuclear molecular complex is present in both samples. The carbonyl
hfac stretch is 1646 cm -1 for both and does not change after coordination of the neutral
radical. The other diagnostic peaks that can be picked out of the baseline of the
coordination complex, 840/841, 716, 647 cm -1 are the same for both sets of spectra. There
are two peaks at 1135 and 796 cm -1 which are present for II-8 which appear to be less
apparent for II-7. It is possible that these stretches may be a differentiating feature for
these spectra. While these data provides some immediate evidence for successful
coordination, elemental analyses and crystallographic measurements are required to
determine unambiguously that the target compounds have been created.
2.2.2. EPR
A very dilute, golden yellow solution of II-1 in methylene chloride was prepared and
analyzed via EPR spectroscopy. The result was a large featureless absorption similar to
that obtained for other DSDA radical species reported in the literature, 8 and can be
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