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1.
A new ruthenium(II) complex, [Ru(bpy)2(Htip)]Cl2 {where bpy = 2,2′-bipyridine and Htip = 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline}, has been synthesized and characterized by 1H NMR spectroscopy, elemental analysis, and mass spectrometry. The pH effects on UV-Vis absorption and emission spectra of the complex have been studied, and the ground- and excited-state acidity ionization constant values have been derived. The calf thymus (ct) DNA binding properties of the complex have been investigated with UV-Vis absorption and luminescence titrations, steady-state emission quenching by [Fe(CN)6]4−, DNA competitive binding with ethidium bromide, DNA melting experiments, and viscosity measurements. The molecular structures and electronic properties of [Ru(bpy)2(Htip)]2+ and deprotonated form [Ru(bpy)2(tip)]+ have also been investigated by means of density functional theory calculations in an effort to understand the DNA binding properties. The results suggest that the complex undergo three-step successive protonation/deprotonation reactions with one of which occurring over physiological pH region, and act as a ct-DNA intercalator with an intrinsic DNA binding constant value on 105 M−1 order of magnitude that is insensitive to pH. 相似文献
2.
Yan-Min Chen 《Journal of inorganic biochemistry》2009,103(10):1395-1404
A novel Ru(II) complex, [Ru(bpy)2(btppz)]Cl2, where bpy = 2,2′-bipyridine and btppz = benzo[h]tripyrido[3,2-a:2′,3′-c:2″,3″-j]phenazine, has been synthesized and characterized. The pH effects on UV-visible (UV-vis) absorption and emission spectra of the complex have been studied and ground- and excited-state ionization constants of the complex have been derived. The calf thymus DNA (ct-DNA) binding properties of the complex were investigated with UV-vis absorption and luminescence spectrophotometric titrations, steady-state emission quenching by [Fe(CN)6]4−, DNA competitive binding with ethidium bromide, DNA melting experiments, reverse salt titrations and viscosity measurements. The complex was demonstrated to act as dual molecular switches: pH-induced “on-off” emission switch with an on-off intensity ratio of ∼54 which is favorably compared with those reported for structurally analogous Ru(II) complexes, and a DNA molecular light switch with a luminescence enhancement factor of 22 as it intercalatively bound to the DNA. 相似文献
3.
An-Guo Zhang Huai-Xia Yang Ke-Zhi Wang 《Journal of biomolecular structure & dynamics》2013,31(6):955-968
Abstract A new Ru(II) complex of [Ru(bpy)2(Hppip)]2+ {bpy = 2,2′-bipyridine; Hppip = 2-(4-(pyridin- 2-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline} has been synthesized by grafting of 2-pyridyl to parent complex [Ru(bpy)2(Hpip)]2+ {Hppip = 2-(4-phenyl)-1H-imidazo[4,5-f] [1,10]phenanthroline}. The acid-base properties of [Ru(bpy)2(Hppip)]2+ studied by UV-visible and luminescence spectrophotometric pH titrations, revealed off-on-off luminescence switching of [Ru(bpy)2(Hppip)]2+ that was driven by the protonation/deprotonation of the imidazolyl and the pyridyl moieties. The complex was demonstrated to be a DNA intercalator with an intrinsic DNA binding constant of (5.56 ± 0.2) × 105 M?1 in buffered 50 mM NaCl, as evidenced by UV-visible and luminescence titrations, reverse salt effect, DNA competitive binding with ethidium bromide, steady-state emission quenching by [Fe(CN)6]4-, DNA melting experiments and viscosity measurements. The density functional theory method was also used to calculate geometric/electronic structures of the complex in an effort to understand the DNA binding properties. All the studies indicated that the introduction of 2-pyridyl onto Hpip ligand is more favorable for extension of conjugate plane of the main ligand than that of phenyl, and for greatly enhanced ct-DNA binding affinity accordingly. 相似文献
4.
The new ligand 2-(4-phenoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (ppip) and its Ru(II) complexes [Ru(2,9-dmp)2(ppip)]2+ (1) and [Ru(4,7-dmp)2(ppip)]2+ (2; 2,9- and 4,7-dmp = 2,9- and 4,7-dimethyl-1,10-phenanthroline, resp.) were synthesized and characterized. The binding properties of the two complexes towards calf-thymus DNA (CT-DNA) in buffered H2O (pH 7.2) were investigated by different spectrophotometric methods and viscosity measurements. Both 1 and 2 strongly bind to CT-DNA by means of intercalation, but with different binding strengths. In contrast to the more tightly bound complex 2, the sterically more-demanding complex 1 showed no fluorescence emission, neither alone nor in the presence of CT-DNA. Our results demonstrate that the position of Me groups on phenanthroline (phen) ancillary ligands significantly affects the overall DNA-recognition propensities of Ru(II)-polypyridyl complexes. Further, the partly resolved complex 2 was shown by circular dichroism (CD) to stereoselectively recognize CT-DNA, in contrast to 1. 相似文献
5.
The solid-state structures for two complexes, 7 and 8, are reported. Complex 7 was prepared by treating Ru(OAc)2(Binap) with two equivalents of HBArF in toluene solution, and represents only the second solid-state structure of a Binap complex, in which the Binap is a 6e donor to the Ru(II). The bonding is maintained in solution as shown via 13C NMR studies. The unusual cation 8, as an salt, arises from prolonged reaction of Ru(OAc)2(Binap) with wet HBF4 (and, subsequently, added HSbF6) in 1,2-dichloroethane. 相似文献
6.
A series of mixed-ligand ruthenium(II) complexes of the type [Ru(en)(2)bpy](2+) (bpy=2,2-bipyridine; 1), [Ru(en)(2)phen](2+) (phen=1,10-phenantroline; 2), [Ru(en)(2)IP](2+) (IP=imidazo[4,5-f][1,10]phenanthroline; 3), and [Ru(en)(2)PIP](2+) (PIP=2-phenylimidazo[4,5-f][1,10]phenanthroline; 4) have been isolated and characterized by UV/VIS, IR, and (1)H-NMR spectral methods. The binding of the complexes with calf thymus DNA has been investigated by absorption, emission spectroscopy, viscosity measurements, DNA melting, and DNA photo-cleavage. The spectroscopic studies together with viscosity measurements and DNA melting studies support that complexes 1 and 2 bind to CT DNA (=calf thymus DNA) by groove mode. Complex 2 binds more avidly to CT DNA than complex 1, complexes 3 and 4 bind to CT DNA by intercalation mode, 4 binds more avidly to CT DNA than 3. Noticeably, the four complexes have been found to be efficient photosensitisers for strand scissions in plasmid DNA. 相似文献
7.
Ashraf SM Kandioller W Mendoza-Ferri MG Nazarov AA Hartinger CG Keppler BK 《化学与生物多样性》2008,5(10):2060-2066
The hydration of nitriles to the corresponding amides is an important reaction for both laboratory and industry purposes. The classical synthesis method requires harsh conditions, gives low yields, and is nonselective due to further hydrolysis of the amides into carboxylic acids. To obtain good yields and high selectivity, transition metal complexes have been utilized as catalysts for this transformation. Herein, a series of Ru(II)- and Os(II)-arene complexes--based on pyranone, thiopyranone, and pyridinone ligands--were assayed on the hydration of chloroacetonitriles. The influence of the substitution pattern of the ligand, and of the nuclearity and of the type of substrate on the yield, the selectivity, and the turnover numbers are discussed. 相似文献
8.
Jean-Paul Collin 《Inorganica chimica acta》2007,360(3):923-930
Three new ruthenium(II) complexes which contain two 1,10-phenanthroline units and a third bis-thioether chelate have been prepared and characterized. For two complexes, the X-ray structure shows a perfect fit between the two phen ligands and the bis-thioethers, with almost perfect C2 symmetry for the Ru(phen)2 unit and the S-containing ligand. This geometrical complementarity is also reflected by π-π stacking between the phen nuclei and the S-borne phenyl rings. In relatively harsher preparation conditions a ruthenium complex composed of one phenanthroline and two bis-thioethers is formed as a result of a scrambling reaction. When a bis-thioether chelate incorporated in a macrocycle also including a 6,6′-disubstituted-2,2′-bipyridine unit is used, 1H NMR study shows that an exo S-bonded ruthenium(II) complex is obtained. In presence of chloride anions a photosubstitution reaction of the bis-thioether chelate takes place selectively and efficiently. 相似文献
9.
In order to systematically perform an experimental and theoretical study on DNA binding and photocleavage properties of transition
metal complexes of the type [M(L)2(L1)](PF6)n · xH2O (where M = Co(III) or Ni(II), L = 1,10-phenanthroline or 2.2′ bipryidine, L1 = Thiophene [2,3-b] quinoline (qt), n = 3 or 2 and x = 5 or 2) have been synthesized and characterized by elemental analysis, IR, 1H NMR, UV and magnetic susceptibility data. The DNA-binding properties of these complexes have been investigated with UV-Vis,
viscosity measurements, thermal denaturation and cyclic voltametric studies. It is experimentally found that all the complexes
are bound to DNA via intercalation in the order [Co(bpy)2(qt)](PF6)3 > [Co(phen)2(qt)](PF6)3 > [Ni(phen)2(qt)](PF6)2 > [Ni(bpy)2(qt)](PF6)2. The photocleavage studies with pUC19 DNA shows that all these complexes promoted the conversion of SC form to NC form in
absence of ‘inhibitors’. 相似文献
10.
Tris-chelate 5-hydroxymethyl-2,2′-bipyridine complexes of ruthenium (II) and the structurally related benzo- and naphthoesters have been isolated. The mer-isomer of the alcohol functionalised complex has been isolated by selective precipitation from methylene chloride and was subsequently functionalised to the benzoester with retention of the geometrical isomerism. The fac- and mer-isomeric forms of the ester complexes were separated using preparative plate silica chromatography and characterised by 1H NMR spectroscopy. X-ray structural analysis of the fac-isomer of both the ester complexes confirmed the product assignment. The photophysical properties of the three isomers were investigated, indicating very similar absorption spectra to [Ru(bipy)3]2+. The emission wavelength was comparable in each case, with the aromatic ester complexes giving a much longer lifetime and higher quantum yields 相似文献
11.
Yasuo Nakabayashi Hiroyuki Inada Yuki Minoura Nobuaki Iwamoto Osamu Yamauchi 《Inorganica chimica acta》2009,362(3):869-4841
For reactions of [{RuCl(bpy)2}2(μ-BL)]2+ (bpy = 2,2′-bipyridine, BL = H2N(CH2)nNH2 (n = 4-8, 12), [Ru2-BL]2+) with mononucleotides, the MLCT absorption bands of [Ru2-BL]2+ blue-shifted with hyperchromism for GMP and hypochromism for TMP with time. Reactions of [Ru2-BL]2+ with GMP or TMP proceed via initial Cl− ions replacement by coordination to N7 of GMP and N3 of TMP, respectively. In competition binding experiments for [Ru2-BL]2+ with GMP versus TMP, only GMP selectively coordinated to ruthenium(II). For reactions with calf thymus (CT) DNA, [Ru2-BL]2+ complexes selectively bind to guanine residues of DNA. The higher degrees of binding of [Ru2-BL]2+ to CT-DNA were observed with increasing n values for H2N(CH2)nNH2, which may be explained by the length of the bridging ligands. Studies on the inhibition of the restriction enzyme Acc I revealed that [Ru2-BL]2+ complexes appear to be covalently favorable for the type of difunctional binding. In addition, it is very interesting to observe that circular dichroism spectroscopy of the supernatants obtained following the reactions of CT-DNA with racemic [Ru2-BL]2+ show enrichments of the solutions in the ΔΔ isomers, demonstrating preferences of the ΛΛ isomers for covalent binding to CT-DNA. 相似文献
12.
The mononuclear dipeptide‐based CuII complexes [CuII(trp‐phe)(phen)(H2O)] ⋅ ClO4 ( 1 ) and [CuII(trp‐phe)(bpy)(H2O)] ⋅ ClO4 ( 2 ) (trp‐phe=tryptophanphenylalanine, phen=1,10‐phenanthroline, bpy=2,2′‐bipyridine) were isolated, and their interaction with DNA was studied. They exhibit intercalative mode of interaction with DNA. The intercalative interaction was quantified by Stern Volmer quenching constant (Ksq=0.14 for 1 and 0.08 for 2 ). The CuII complexes convert supercoiled plasmid DNA into its nicked circular form hydrolytically at physiological conditions at a concentration as low as 5 μM (for 1 ) and 10 μM (for 2 ). The DNA hydrolysis rates at a complex concentration of 50 μM were determined as 1.74 h−1 (R=0.985) for 1 and 0.65 h−1 (R=0.965) for 2 . The rate enhancement in the range of 2.40–4.10×107‐fold compared to non‐catalyzed double‐stranded DNA is significant. This was attributed to the presence of a H2O molecule in the axial position of the Cu complexes. 相似文献
13.
Laurent Bouffier Pascal Dumy Andrée Kirsch-De Mesmaeker 《Inorganica chimica acta》2007,360(10):3162-3168
A mononuclear Ru(II) complex based on a new heptacyclic ligand (dpqp) has been prepared and characterized by NMR spectroscopy, ES mass spectrometry and electrochemistry. It forms dimers and aggregates of up to seven complex units in CH3CN solution observed by ESMS. The monomer has an extremely weak luminescence in water or even in organic solvent probably due to the existence of a low lying π-π∗ excited state centered on the heptacycle. In spite of the strong interaction of the complex with DNA, its luminescence is not enhanced by the DNA microenvironment. 相似文献
14.
Synthesis of new bichromophoric di- and pentanuclear complexes 2-7 by datively binding (bpy)2RuII, (phen)2RuII and Cp (PPh3)RuII units to the periphery of [Co(OBTTAP)], 1, and their spectroscopic properties are described. IR, 1H NMR, UV-Vis, and mass spectral data were used for their characterization. Relative intensities and positions of the Soret and Q-bands absorptions in the di- and pentanuclear complexes were observed shifted vis-à-vis that in the precursor complex [Co(OBTTAP)], 1. These complexes particularly, those possessing [Co(OBTTAP)] and (bpy)2RuII/(phen)2RuII units, exhibited efficient inter-component electronic excitation energy transfer in their fluorescence excitation-emission spectra, that are suggestive of a high degree of inter-component electronic interaction in them. Also, the electrode activity of the complexes improved upon binding of the peripheral units and they exhibited multiple one-electron reversible oxidation waves in the cyclic voltammograms. These effects have been explained in terms of dπ(S)-dπ(Ru) interactions. 相似文献
15.
Anthony Baker 《Inorganica chimica acta》2005,358(12):3513-3518
New ruthenium(II) complexes with cyanamide ligands, cis-[Ru(bpy)2(Ipcyd)2] (1) and [Ru(bpy)2(OHpcyd)2] (2) (bpy = 2,2′-bipyridine, Ipcyd = 4-iodophenylcyanamide anion, OHpcyd = 4-(3-hydroxy-3-methylbut-1-ynil)phenylcyanamide), have been prepared and characterized by UV-Vis, IR and 1H NMR spectroscopies as well as electrochemical technique (CV). The complex cis-[Ru(bpy)2(Ipcyd)2] (1) crystallized with empirical formula of C34H24I2N8Ru in a monoclinic crystal system and space group of P21/c with a = 11.769(7) Å, b = 24.188(12) Å, c = 11.623(2) Å, β = 91.63(3)°, V = 3308(3) Å3 and Z = 4. 相似文献
16.
Two new ruthenium complexes [Ru(bpy)2(mitatp)](ClO4)21 and [Ru(bpy)2(nitatp)](ClO4)22 (bpy = 2,2′-bipyridine, mitatp = 5-methoxy-isatino[1,2-b]-1,4,8,9-tetraazatriphenylene, nitatp = 5-nitro-isatino[1,2-b]-1,4,8,9-tetraazatriphenylene) have been synthesized and characterized by elemental analysis, 1H NMR, mass spectrometry and cyclic voltammetry. Spectroscopic and viscosity measurements proved that the two Ru(II) complexes intercalate DNA with larger binding constants than that of [Ru(bpy)2(dppz)]2+ (dppz = dipyrido[3,2-a:2′,3′-c]phenazine) and possess the excited lifetime of microsecond scale upon binding to DNA. Both complexes can efficiently photocleave pBR322 DNA in vitro under irradiation. Singlet oxygen (1O2) was proved to contribute to the DNA photocleavage process, the 1O2 quantum yields was determined to be 0.43 and 0.36 for 1 and 2, respectively. Moreover, a photoinduced electron transfer mechanism was also found to be involved in the DNA cleavage process. 相似文献
17.
The trinuclear [{RuII(bpy)2(bpy-terpy)}2CoII]6+ complex (16+) in which a Co(II)-bis-terpyridine-like centre is covalently linked to two Ru(II)-tris-bipyridine-like moieties by a bridging bipyridine-terpyridine ligand has been synthesised and characterised. Its electrochemical, photophysical and photochemical properties have been investigated in CH3CN. The cyclic voltammetry exhibits two successive reversible oxidation processes, corresponding to the CoIII/CoII and RuIII/RuII redox couples at E1/2 = −0.06 and 0.91 V vs Ag/Ag+ 10 mM, respectively. The one-electron oxidized form of the complex, [{RuII(bpy)2(bpy-terpy)}2CoIII]7+ (17+) obtained after exhaustive electrolysis carried out at 0.2 V is fully stable. 16+ and 17+ are only poorly luminescent, indicating that the covalent linkage of the Ru(II)-tris-bipyridine centre to the cobalt subunit leads to a strong quenching of the RuII excited state by an intramolecular process. Luminescence lifetime experiments carried out at different temperatures indicate that the transfer is more efficient for 17+ compare to 16+ due to lower activation energy. Continuous irradiation of 17+ performed at 405 nm in the presence of P(Ph)3 acting as sacrificial electron donor leads to its quantitative reduction into 16+, whereas similar experiment starting from 16+ with a sulfonium salt as sacrificial electron acceptor converts 16+ into 17+ with a slower rate and a maximum yield of 80%. These photoinduced electron transfers were followed by UV-Visible spectroscopy and compared with those obtained with a simple mixture of both mononuclear parent complexes i.e. [RuII(bpy)3]2+ and [CoII(tolyl-terpy)2]2+ or [CoIII(tolyl-terpy)2]3+ (tolyl-terpy = 4′-(4-methylphenyl)-2,2′:6′,2′′-terpyridine). 相似文献
18.
Hong-Ju Yin An-Guo Zhang Li-Hua Gao Hua Zhao 《Nucleosides, nucleotides & nucleic acids》2020,39(4):592-614
AbstractDNA groove binders have been poorly studied as compared to the intercalators. A novel Ru(II) complex of [Ru(aeip)2(Haip)](PF6)2 {Haip?=?2-(9-anthryl)-1H-imidazo[4,5-f][1,10]phenanthroline and aeip = 2-(anthracen-9-yl)-1-ethyl-imidazo[4,5-f][1, 10]phenanthroline} is synthesized and characterized by elemental analysis, 1H NMR spectroscopy and mass spectrometry. The complex is evidenced to be a calf-thymus DNA groove binder with a large intrinsic binding constant of 106 M?1 order of magnitude as supported by UV–visible absorption spectral titrations, salt effects, DNA competitive binding with ethidium bromide, DNA melting experiment, DNA viscosity measurements and density functional theory calculations. The acid-base properties of the complex studied by UV–Vis spectrophotometric titrations are reported as well. 相似文献
19.
Eun Hwa Kim Joong Min Lee Young Moo Jun Byeong Hyo Kim 《Inorganica chimica acta》2009,362(5):1577-1584
New bridging ligands, such as bpy-(COOCH2)-bpy (BL1), mbpy-(CH2)3COOCH2-bpy (BL2), bpy-COO(CH2)6OOC-bpy (BL3), and bpy-COOCH2PhPhCH2OOC-bpy (BL4), have been synthesized and coordinated to [RuL2(acetone)2](PF6)2 for various [Ru(L)2(BL)Ru(L)2](PF6)4-type dinuclear ruthenium complexes (where BL = BL1, BL2, BL3, BL4, and L = bpy, o-phen, DTDP). Their electrochemical redox potentials, spectroscopic properties and relative electrochemiluminescence were investigated in detail. All dinuclear Ru complexes exhibit MLCT (metal-to-ligand charge transfer) absorption and luminescence bands in the visible region. ECL intensities of dinuclear ruthenium(II) complexes were affected not only by the kind of the ligand, but also by the nature of the bridging ligand. Among the synthesized dinuclear Ru complexes, [(DTDP)2Ru(mbpy)-(CH2)3COOCH2-(bpy)Ru(DTDP)2](PF6)4 exhibited enhanced ECL intensities as high as 2.9 times greater than that of the reference, [Ru(o-phen)3](PF6)2. 相似文献
20.
The mixed-ligand complexes [Cu(II)(HisLeu)(phen)](+) (1) and [Cu(II)(HisSer)(phen)](+) (2; phen=1,10-phenanthroline) were synthesized and characterized. The intercalative interaction of the Cu(II) complexes with calf-thymus DNA (CT-DNA) was probed by UV/VIS and fluorescence titration, as well as by thermal-denaturation experiments, and the intrinsic binding constants (K(b)) for the complexes with 1 and 2 were 4.2x10(3) and 4.9x10(3) M(-1), resp. Both complexes were found to be efficient catalysts for the hydrolytic cleavage of plasmid pUC19 DNA, as tested by gel electrophoresis, converting the DNA from the supercoiled to the nicked-circular form at rate constants of 1.32 and 1.40 h(-1) for 1 and 2, resp. 相似文献