Photophysical and Structural Properties of Cyanoruthenate Complexes of Hexaazatriphenylene
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- 作者：Juan-Manuel Herrera ; Simon J. A. Pope ; Anthony J. H. M. Meijer ; Timothy L. Easun ; Harry Adams ; Wassim Z. Alsindi ; Xue-Zhong Sun ; Michael W. George ; Stephen Faulkner ; Michael D. Ward
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：September 19, 2007
- 年：2007
- 卷：129
- 期：37
- 页码：11491 - 11504
- 全文大小：767K
- 年卷期：v.129,no.37(September 19, 2007)
- ISSN：1520-5126
文摘
The tritopic bridging ligand hexaazatriphenylene (HAT) has been used to prepare the mono-,di-, and trinuclear cyanoruthenate complexes [Ru(CN)4(HAT)]2- ([1]2-), [{Ru(CN)4}2(2-HAT)]4- ([2]4-), and[{Ru(CN)4}3(3-HAT)]6- ([3]6-). These complexes are of interest both for their photophysical propertiesand ability to act as sensitizers, associated with strong MLCT absorptions; and their structural properties,with up to 12 externally directed cyanide ligands at a single "node" for preparation of coordination networks.The complexes are strongly solvatochromic, with broad and intense MLCT absorption manifolds arisingfrom the presence of low-lying * orbitals on the HAT ligand, as confirmed by DFT calculations; in aproticsolvents [3]6- is a panchromatic absorber of visible light. Although nonluminescent in fluid solution, thelowest MLCT excited states have lifetimes in D2O of tens of nanoseconds and could be detected by time-resolved IR spectrosocopy. For dinuclear [2]4- and trinuclear [3]6- the TRIR spectra are indicative ofasymmetric MLCT excited states containing distinct Ru(III) and Ru(II) centers on the IR time scale. Thecomplexes show red 3MLCT luminescence as solids and in EtOH/MeOH glass at 77 K. Ln(III) salts of[1]2-, [2]4-, and [3]6- form infinite coordination networks based on Ru-CN-Ln bridges with a range ofone-, two-, and three-dimensional polymeric structures. In the Yb(III) and Nd(III) salts of [3]6- the complexanion forms an 8-connected node. Whereas all of the Gd(III) salts show strong 3MLCT luminescence inthe solid state, the Ru-based emission in the Nd(III) and Yb(III) analogues is substantially quenched by Ru Ln photoinduced energy transfer, which results in sensitized near-infrared luminescence from Yb(III)and Nd(III).