Low Quantum Yields of Relaxed Electron Transfer Products of Moderately Coupled Ruthenium(II)−Cobalt(III) Compounds on the Subpicosecond Laser Excitation
摘要:
Photoinduced electron-transfer reactions of [(tpy)Ru-II(tpy-tpy)Co-III(tpy)]5+ (tpy = 2,2':6',2"-terpyridine and tpy-tpy = 6',6"-bis(2-pyridyl)-2,2':4',4":2",2"'-quarterpyridyne), [(tpy)Ru-II(tpy-ph-tpy)Co-III(tpy)](5+) (tpy-ph-tpy = 1,4-bis[2,2':6',2"-terpyridine-4'-yl]benzene), and [(bpy)(2)Ru-II(tpphz)Co-III(bpy)(2)](5+) (bpy = 2,2'-bipyridine, and tpphz = tetrapyrido[3,2-a:2',3'-c:3",2"-h::2"',3"'-j]phenazine) were studied in the range 140-298 K by means of subpicosecond transient absorption spectroscopy. (MLCT)-M-3(Ru) of [(tpy)Ru-II(L-L)Co-III(tpy)](5+) (L-L: tpy-tpy and tpy-ph-tpy) underwent intramolecular electron-transfer (EET) reaction to form [Ru-2(III)(tpy)(L-L)Co-2(II)(tpy)](5+) in a shorter time than 10 ps. Low quantum yields of the EET products (0.53 for tpy-tpy and 0.41 for tpy-ph-tpy in butyronitrile at 298 K) measured before the fast return electron-transfer were found as in the intermolecular electron-transfer quenching of (MLCT)-M-3(Ru) by [Co(tpy)(2)](3+). The quantum yield of [(tpy)-Ru-II(tpy-tpy)Co-II(tpy)](5+) (Phi) decreases to 0.38 in a slowly reorganizing solvent of propylene carbonate and that of [(tpy)Ru-II(tpy-ph-tpy)Co-III(tpy)](5+) to 0.21 at 180 K. The reductions in the EET yields, 1 - Phi, can be ascribed to a fast transition of the nonrelaxed EET product to the lowest triplet d-d* state of [Co-III(tpy)(2)] moiety during the solvent reorganization. A tunneling transition of the nonrelaxed EET products to the lowest lying d-d excited-state of [Co-III(tpy)(2)] moiety takes place as a hole transfer, HT, from the dpi-orbital of Ru(III) to that of Co(II) with a configuration of dpi(6)dsigma*. An electronic coupling of dpi(Ru)-dpi(Co) estimated from the intensity of inter-valence transition of [(tpy)Ru-III(L-L)Ru-II(tpy)](5+) (Collin, J.-P.; Laine, P.; Launay, J.-P.; Sauvage, J.-P.; Sour, A. J. Chem. Soc., Chem. Commun. 1993, 434) is large enough to carry out the HT. The weak coupling of dpi(Ru)-dpi(Co) in the case of [(bpy)(2)Ru(tpphz)Co(bpy)(2)](5+) attenuates the HT rate to bring about a high yield of EET (0.8). The possibility that energy-transfer of (MLCT)-M-3(Ru) to the Co(III) moiety via an intermediate super-exchange coupling between dpi(Ru) and dpi(Co) occurs in competition with the EET of [(tpy)Ru-III(tpy-ph-tpy)Co-II(tpy)](5+) is also pursued.
已经制备了一系列基于马参部分的新的Ru II Schiff碱复合物。其中包括四种包含Ni II,Pd II或Pt II的柔性单金属Ru II化合物和六个刚性双金属类似物阳离子进入丹参络合位点。稳态发光滴定表明该化合物具有光探针G-四链体(G4)DNA的能力。此外,席夫碱的大量结构变化允许广泛评估配体表面,柔性和电荷对化合物与G4 DNA相互作用的影响。这要归功于圆二色谱熔融分析和生物层干涉法研究,这些研究指出了Ru II Schiff碱基配合物对G4 DNA的高亲和力和良好的选择性。在纤维素用最有前途的化合物进行了研究。观察到化合物在核以及在核仁中的细胞摄取。在黑暗和光照射下,用U2OS骨肉瘤细胞进行细胞活力实验,从而可以测量IC 50值和光指数。他们显示了光照射除了在黑暗中分子的低细胞毒性外,还对药物的活性发挥了重要作用。总之,报告的结果强调了Ru II Schiff碱基复合物作为开发潜在的靶向诊断或治疗化合物的G4
Two structurally analogous ruthenium complexes as naked-eye and reversible molecular “light switch” for G-quadruplex DNA
作者:Xiao-Hui Lu、Shuo Shi、Jun-Liang Yao、Xing Gao、Hai-Liang Huang、Tian-Ming Yao
DOI:10.1016/j.jinorgbio.2014.07.003
日期:2014.11
that both Ru-complexes exhibited a remarkable “light switch” effect in the presence of hybrid G-quadruplex DNA. Interestingly, the “light switch” can be repeated off and on through the successive addition of Cu2 + ions and EDTA, and all these behaviors can be observed even by the naked eyes. Moreover, FRET melting assay revealed that both complexes could be potential stabilizers for G-quadruplex architectures
The complex [(bpy)2Ru(tpphz)]2+(tpphz = tetrapyridophenazine), is obtained by reaction of [(bpy)2Ru(phendione)]2+with 5,6-diamino-1,10-phenanthroline; upon reaction with [(bpy)2Ru(Me2CO)2]2+, the fully conjugated dimer [(bpy)2Ru(tpphz)Ru(bpy)2]4+ is obtained.
Synthesis of Novel Substituted 1,10-Phenanthrolines
作者:Heather Camren、Mei-Yueh Chang、Liansheng Zeng、Mark E. McGuire
DOI:10.1080/00397919608003733
日期:1996.3
Abstract The syntheses of both 5-amino-6-nitro-1,10-phenanthroline and 5,6-diamino-1,10-phenanthroline (starting from 5-nitro-1,10-phenanthroline) are described in detail.
DNA binding and cleavage properties of a newly synthesised Ru(II)-polypyridyl complex
作者:Amrita Ghosh、Amit Mandoli、D. Krishna Kumar、Narendra Singh Yadav、Tamal Ghosh、Bhavanath Jha、Jim A. Thomas、Amitava Das
DOI:10.1039/b906756f
日期:——
The single crystal X-ray structure of the newly synthesized ruthenium (II)-polypyridyl complex, [(bpy)(2)Ru(L)](PF(6))(2) (1) (bpy is 2,2'-bipyridyl and L is 2-methyl-2H-1,3,7,8-tetraaza-cyclopenta[l]phenanthren-2-ol revealed a near planar conformation for the fused imidazole moiety, suggesting the complex may be capable of binding to duplex DNA. Binding-induced changes in spectral properties, along
Observation of supramolecular π–π dimerization of a dinuclear ruthenium complex by 1H NMR and ESMS
作者:Eléna Ishow、André Gourdon
DOI:10.1039/a805809a
日期:——
The dinuclear ruthenium complex of bisdipyrido[3,2-f:2â²,3â²-h]quinoxalo}[2,3-e:2â²,3â²-l]pyrene (bqpy) forms dimers in solution maintained only by ÏâÏ stacking of the bridging ligand, stable enough to be observed not only by 1H NMR spectroscopy but also by electrospray mass spectrometry at low accelerating cone voltage.