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

The d 10 zinc complexes II-7 and II-8 however, behave differently as the local angles
around zinc are, on average, much further from the ideal 90°, as is expected for a d 10
system as it possesses no ligand field stabilization energy. However these complexes are
still most accurately described as possessing octahedral site geometry. The coordination
geometry about the manganese ion in complex II-6, by contrast, can be better described
as trigonal prismatic and is roughly the same for both of the molecules in the asymmetric
unit. This is consistent with a six-coordinate high-spin d 5 complex which would also
theoretically possess no ligand field stabilization energy.
The most important aspect of the crystallographic data is the crystal packing
information. The binuclear DSDA nickel complex II-5 was shown to have close Se...Se
contacts between neighboring complexes which are well within the sum of the van der
Waal’s radii for two selenium atoms at 3.215 Å, shown in Figure 2-6.
Figure 2-6. Crystallographic representation of neighboring DSDA nickel complexes II-5 showing close
Se...Se contacts. The backbone of the ancillary hfac ligand and H atoms have been removed for clarity.
Of all the examples of binuclear coordination complexes of II-2 and II-1, this is the
only molecule that forms dimers which have necessarily adapted the trans-antarafacial
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