报道了用t Bu或C 12 H 25功能化的两个联吡啶-六-周边-六苯并二氢呋喃(bpy-HBC)配体及其Re(I)三羰基氯配合物的合成,并使用光谱和计算方法研究了它们的电子性质。金属配合物表现出不同寻常的性质,我们使用时间分辨红外光谱观察到了长寿命激发态的形成。根据不同的溶剂,这似乎是形式Rebpy的• - HBC •+或以bpy为中心的π,π*状态。TD-DFT计算支持了这些系统的供体-受体电荷转移特性,其中HBC是供体,bpy是受体。基态的光学性质主要由HBC发色团主导,另外还有明显的复合物跃迁,一个跃迁与MLCT 450 nm(ε> 17000 L mol –1 cm –1)有关,另一个与HBC /金属向bpy的电荷转移有关,称为MLLCT谱带(373 nm,ε= 66 000 L mol –1 cm –1)。这些分配也得到共振拉曼光谱的支持。
Synthesis, metal complex formation, and switching properties of spiropyrans linked to chelating sites
摘要:
The synthesis of 5-pinacolato-2,2'-bipyridine and its applicability in cross-coupling reactions is reported. The use of this framework in Suzuki type cross-coupling reactions, together with a recently published way to achieve indolization has been used to synthesize new spiropyran systems attached to two bipyridine moieties. The indolization method followed, is based on an 'in situ' hydrolysis/Fischer cyclization protocol reported by Buchwald and co-workers. The synthesis of a new phenanthroline based spirooxazine attached to a bipyridine moiety is also reported. One of the spiropyran system was used as a ligand to form a ruthenium metal complex. There photophysical properties were tested with respect to the application as sensitizer in functionalized, wire-type bridging ligands in heteronuclear metal complexes. (C) 2002 Elsevier Science Ltd. All rights reserved.
作者:Scott A. Sadler、Hazmi Tajuddin、Ibraheem A. I. Mkhalid、Andrei S. Batsanov、David Albesa-Jove、Man Sing Cheung、Aoife C. Maxwell、Lena Shukla、Bryan Roberts、David C. Blakemore、Zhenyang Lin、Todd B. Marder、Patrick G. Steel
DOI:10.1039/c4ob01565g
日期:——
The iridium-catalysed CâH borylation is a valuable and attractive method for the preparation of aryl and heteroaryl boronates. However, application of this methodology for the preparation of pyridyl and related azinyl boronates can be challenged by low reactivity and propensity for rapid protodeborylation, particularly for a boronate ester ortho to the azinyl nitrogen. Competition experiments have revealed that the low reactivity is due to inhibition of the active catalyst through coordination of the azinyl nitrogen lone pair at the vacant site on the iridium. This effect can be overcome through the incorporation of a substituent at C-2. Moreover, when this is sufficiently electron-withdrawing protodeborylation is sufficiently slowed to permit isolation and purification of the C-6 boronate ester. Following functionalization, reduction of the directing C-2 substituent provides the product arising from formal ortho borylation of an unhindered pyridine ring.
作者:Ena T. Luis、Hasti Iranmanesh、Kasun S. A. Arachchige、William A. Donald、Gina Quach、Evan G. Moore、Jonathon E. Beves
DOI:10.1021/acs.inorgchem.8b01157
日期:2018.7.16
We have designed linear metalloligands which contain a central photoactive [Ru(N∧N)3]2+ unit bordered by peripheral metal binding sites. The combination of these metalloligands with Zn(II) and Fe(II) ions leads to heterometallic tetrahedral cages, which were studied by NMR spectroscopy, mass spectrometry, and photophysical methods. Like the parent metalloligands, the cages remain emissive in solution