Red-Emitting [Ru(bpy)2(N-N)]2+ Photosensitizers: Emission from a Ruthenium(II) to 2,2′-Bipyridine 3MLCT State in the Presence of Neutral Ancillary “Super Donor” Ligand
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- 作者：Amlan K. Pal ; Samik Nag ; Janaina G. Ferreira ; Victor Brochery ; Giuseppina La Ganga ; Antonio Santoro ; Scolastica Serroni ; Sebastiano Campagna ; Garry S. Hanan
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：February 3, 2014
- 年：2014
- 卷：53
- 期：3
- 页码：1679-1689
- 全文大小：531K
- ISSN：1520-510X
文摘
The synthesis and characterization of a novel family of [RuII(bpy)2(N-N)](PF6)2 (bpy = 2,2鈥?bipyridine) complexes are reported, where N-N = pyridine/pyrimidine/pyrazine functionalized in different positions with the electron-donating bicyclic hexahydropyrimidopyrimidine (hpp) unit. A series of bidentate ligands 1a鈥?b>5a were synthesized in good to high yields (55鈥?6%). The corresponding complexes 1b, 2b, and 5b were prepared in n-butanol, while complexes 3b and 4b were prepared in a mixture of n-butanol and water (1/1, v/v) in modest to good yields (23鈥?6%). Both ligand and complex structures were fully characterized by a variety of techniques, including X-ray crystallography. In cyclic voltammetric studies, all the complexes exhibit a RuIII/II couple, which is 500 mV less positive than the RuIII/II couple in Ru(bpy)32+. The 1MLCT and 3MLCT states of all of the complexes (530鈥?60 nm/732鈥?45 nm) are shifted bathochromically in comparison to those of Ru(bpy)32+ (450 nm/620 nm). These values are in good agreement with DFT and TD-DFT calculations.