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

eaches the lower end of the investigated temperature regime and hysteresis is observed
at 1.8 K. The room temperature magnetic study revealed a broad maximum at 60 K
indicating a short-range antiferromagnetic interaction prior to the onset of the long-range
ordering at 36 K. 82 Interestingly pressure related studies performed on this compound
found that increasing the pressure up to 16 kbar resulted in a substantial increase of the
ordering temperature up to 64.5 K. 85
It is rather important that spin canted
antiferromagnetism can only occur in non-centrosymmetric space groups.
The
phenomenon arises from the antiferromagnetic alignment of spins on two magnetic
sublattices which are not exactly antiparallel. 86
As 1,2,3,5-DTDA based systems are one of the major focal points of this thesis a
brief discussion of the methodologies employed for their synthesis is appropriate. These
types of radicals have received a lot of attention and this is due, in part, to the ease with
which they can be prepared and purified. The procedures used to obtain them are well
established 87 and usually call for a nitrile to be reacted with lithium bis(trimethylsilyl)
amide and subsequently treated with trimethylsilyl chloride to give the trisilyl amidine. 88
These compounds are usually low melting solids (in the cases of mono DTDAs) and can
therefore often be purified by vacuum distillation. These compounds can then be reacted
with SCl 2 or S 2 Cl 2 to give the dithiadiazolium cation with a chloride counter ion. The
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