Deep Blue Mixed-Valent PtIIIPtIIIPtII Complex [Pt3Br2(μ-pz)6] (pz=Pyrazolate) Showing Valence-Detrapping Behavior in Solution
✍ Scribed by Keisuke Umakoshi; Takashi Kojima; Yong Hun Kim; Masayoshi Onishi; Yoshihide Nakao; Shigeyoshi Sakaki
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 306 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0947-6539
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The oxidation of the pyrazolate bridged cyclic Pt^II^ trimer, [Pt~3~(μ‐pz)~6~] (1), in the presence of bromide ion gave a deep blue mixed‐valent Pt^II,III,III^ complex, [Pt~3~Br~2~(μ‐pz)~6~] (2). The structural analysis of 2 disclosed that the complex has localized PtPt bond. Our theoretical calculations revealed that the HOMO and LUMO of Pt~3~^II,III,III^ species mainly consists of (d~σ~–d~σ~) and (d~σ~–d~σ~)* orbitals, respectively, and the origin of deep blue color of the bromo complex, 2, arises from the (d~σ~–d~σ~)→(d~σ~–d~σ~)* transition. Unique fluxional behavior was observed due to valence‐detrapping of 2 in solution. The activation parameters of the valence‐detrapping of 2 obtained by Eyring analyses were Δ__H__^≠^=37(2) kJ mol^−1^ and Δ__S__^≠^=−67(7) J mol^−1^ K^−1^.