Photophysics of the Platinum(II) Terpyridyl Terpyridylacetylide Platform and the Influence of FeII and ZnII Coordination
详细信息 查看全文
- 作者：Maria L. Muro ; Sté ; phane Diring ; Xianghuai Wang ; Raymond Ziessel ; Felix N. Castellano
- 刊名：Inorganic Chemistry
- 出版年：2008
- 出版时间：August 4, 2008
- 年：2008
- 卷：47
- 期：15
- 页码：6796-6803
- 全文大小：399K
- 年卷期：v.47,no.15(August 4, 2008)
- ISSN：1520-510X
文摘
The synthesis, structural characterization, and photoluminescence (PL) properties of the square-planar terpyridylplatinum(II) complex [tBu3tpyPtCCtpy]+ (1) and the octahedral trinuclear FeII and ZnII analogues [Fe(tBu3tpyPtCCtpy)2]4+ (2) and [Zn(tBu3tpyPtCCtpy)2]4+ (3) are described. The photophysical properties of the mononuclear PtII complex 1 are consistent with a charge-transfer excited-state parentage producing a large Stokes shift with a concomitant broad, structureless emission profile. The Fe-based ligand-field states in 2 provide an efficient nonradiative deactivation pathway for excited-state decay, resulting in a nonemissive compound at room temperature. Interestingly, upon chelation of 1 with ZnII, a higher energy charge-transfer emission with a low-energy shoulder and a 215 ns excited-state lifetime is produced in 3. A spectroscopically identical species relative to 3 was produced in control experiments when 1 was reacted with excess protons (HClO4) as ascertained by UV−vis and static PL spectra measured at room temperature and 77 K. Therefore, the chelation of ZnII to 1 is acid−base in nature, and its Lewis acidity renders the highest occupied molecular orbital level in 1 much less electron-rich, which induces a blue shift in both the absorption and emission spectra. At 77 K, complexes 1, 3, and protonated 1 display at least one prevalent vibronic component in the emission profile (1360 cm−1) resembling PL emanating from a ligand-localized excited-state, indicating that these emitting states are inverted relative to room temperature. These results are qualitatively confirmed by the application of time-dependent theory using only the 1360 cm−1 mode to reproduce the low-temperature emission spectra.