The preparation and structural characterization of the neutral, square planar complexes [Pt
II(
tbpy)(A)] (
1), [Pt
II(
tbpy)(B)] (
2), and [Pt
II(PPh
3)
2(B)] (
3) have been accomplished, where (
tbpy) = 4,4'-di-
tert-butylpyridine, (A)
2- =3,6-bis(trimethylsilyl)-1,2-benzenedithiolate(2-), and (B)
2- = 1,2-bis(4-
tert-butylphenyl)ethylene-1,2-dithiolate(2-)and (A
![](/images/entities/bull.gif)
)
1- and (B
![](/images/entities/bull.gif)
)
1- represent the corresponding monoanionic radicals. Electrochemical and chemical one-electronoxidation of
1 and
2 in CH
2Cl
2 solution affords the monomeric monocations [Pt
II(
tbpy)(A
![](/images/entities/bull.gif)
)]
+ (
1a) and [Pt
II(
tbpy)(B
![](/images/entities/bull.gif)
)]
+(
2a), both of which possess an
S =
1/
2 ground state. The corresponding spin doublet monocationic dimers [Pt
II2(
tbpy)
2(A)(A
![](/images/entities/bull.gif)
)]
+ (
1b) and [Pt
II2(
tbpy)
2(B)(B
![](/images/entities/bull.gif)
)]
+ (
2b) were electrochemically generated in solution (50% oxidation) andidentified by X-band EPR spectroscopy. Complete one-electron oxidation of
1 and
2 yielded the diamagnetic dimers[Pt
II2(
tbpy)
2(A
![](/images/entities/bull.gif)
)
2]
2+ (
1c) and [Pt
II2(
tbpy)
2(B
![](/images/entities/bull.gif)
)
2]
2+ (
2c) which are in equilibrium with the corresponding paramagneticmonomers
1a and
2a in solution. The crystal structure of [Pt
II2(
tbpy)
2(B
![](/images/entities/bull.gif)
)
2](PF
6)
2·3CH
2Cl
2 (
2c) revealed acentrosymmetric, lateral dimer whose bridging part is a Pt
II2(
2-S)
2 rhomb; the metal ions possess a square basedpyramidal geometry. Solid-state sulfur K-edge X-ray absorption spectra of
1,
2,
2a,
2c, and [Pt
II(B
![](/images/entities/bull.gif)
)
2]
0 (
4) havebeen recorded, which clearly show that a sulfur-centered radical (B
![](/images/entities/bull.gif)
)
1- is present in
2a,
2c, and
4. The absenceof ligand-based radicals in
1 and
2 is also clearly established. One-electron oxidation of [Pt(PPh
3)
2(B)] (
3) affordedonly the spin doublet species [Pt
II(PPh
3)
2(B
![](/images/entities/bull.gif)
)]
+ (
3a); no dimer formation was detected. Synthesis and crystal structureof square planar [Pt
II(B
![](/images/entities/bull.gif)
)
2]
0·thf are also reported.