共查询到20条相似文献,搜索用时 0 毫秒
1.
Yali Sun 《Inorganica chimica acta》2010,363(1):283-287
Here we describe the efficient high yield atmospheric pressure microwave-assisted synthesis for seven distinct RuII coordination complexes relevant to solar energy conversion schemes and dye sensitized solar cells. In all instances, the reaction times have been markedly shortened, concomitant with higher yields with little or no need for subsequent purification and several multi-step reactions proceeded flawlessly in a single pot. Importantly, we observed no evidence for the decarboxylation of the essential metal oxide surface-anchoring 4,4′-diethylester-2,2′-bipyridine or 4,4′-dicarboxy-2,2′-bipyridine ligands as long as open reaction vessel conditions were utilized; these functionalities are not tolerant to sealed microwave reaction (superheated solvent/pressurized) conditions. The combined results suggest that microwave-assisted chemistry is indeed a valuable tool as far as RuII coordination chemistry is concerned and can likely be applied in the combinatorial pursuit of new dyes bearing sensitive functionalities. 相似文献
2.
Three new complexes [Pt(dpop)(Cl)2], [(Cl)2Pt(dpop)Pt(Cl)2] and [(bpy)2Ru(dpop)Pt(Cl)2](PF6)2 (dpop = dipyrido(2,3-a:3′,2′-h)phenazine) were prepared and studied. The electronic absorption spectra of the complexes display Pt dπ → dpop π* and Ru dπ → dpop π* MLCT transitions at longer wavelengths than for previously reported similar complexes. Results of cyclic voltammograms show reversible dpop centered reductions while for the mixed metal [(bpy)2Ru(dpop)Pt(Cl)2]2+ an irreversible Pt(II) oxidative wave precedes the Ru(II) oxidation/reduction couple. Spectroelectrochemical results show that all oxidative and reductive processes are completely reversible. The [(Cl)2Pt(dpop)Pt(Cl)2] complex cleaves in solution with pseudo-first order kinetics resulting in loss of the Pt dπ → dpop π* MLCT transition at 545 nm. 相似文献
3.
Feiyue WuRandolph P Thummel 《Inorganica chimica acta》2002,327(1):26-30
The ligands 3,3′-dimethylene-2,2′-bibenzo[g]quinoline and bisbenzo[2,3:9,8]-1,10-phenanthroline have been coordinated with Ru(II) to form both tris- and mixed ligand complexes. These species are highly congested about the metal center but can be formed through the use of microwave irradiation. Shielding and deshielding effects on the chemical shifts of the aryl as well as the bridge protons reveal important conformational effects. Bathochromic shifts are observed in the electronic absorption spectra, associated with increased delocalization of the ligand and lowering of the π*-energy level. Similar effects are observed for the reduction potentials while the oxidation potentials are much less sensitive to ligand structure. 相似文献
4.
Mona Abboud 《Inorganica chimica acta》2009,362(14):4953-345
One-step syntheses are reported of 4′-(pyrrol-2-yl)-2,2′;6′,2″-terpyridine, 4-(pyrrol-2-yl)-2,6-di(pyrazol-2-yl)pyridine and of their homoleptic Ru(II) complexes, in good to very good yields. DFT calculations confirmed that the pyrrole rings lay coplanar with the tridentate cores and constituted effective π-donors, but also showed that the properties of the Ru(II) complexes defied classical analyses based on localized metal- or ligand-centred orbitals. The low-potential electrochemical oxidations led to electropolymerization but were not purely pyrrole-centred. The low-energy electronic spectral absorptions were not purely metal-to-ligand charge transfer (MLCT) in character, but resulted from mixed metal-to-ligand and intraligand transitions. The complexes’ photosensitization abilities showed that the pyrrole groups were beneficial to the survival of the photoexcited states, albeit not as much as p-tolyl groups. 相似文献
5.
Heteroleptic complexes [Ru(bpy)2(R2bpm)]2+, where bpy = 2,2′-bipyridine and R2bpm = 6,6′-diaryl-4,4′-bipyrimidine, have been synthesized and characterized, together with the homoleptic complex [Ru(R2bpm)3]2+, in which R2bpm = 6,6′-diphenyl-4,4′-bipyrimidine. The substituent aryl on the bipyrimidine has significant effects on the properties of these complexes as compared to the parent [Ru(bpy)2(bpm)]2+ complex. The complexes exhibit Ru-to-bpm charge transfer (CT) absorptions centered at about 540 nm and Ru-to-bpy CT absorptions centered at about 435 nm. The assignment of the low energy absorptions is supported by the relative ease of the reduction of the new complexes as compared to [Ru(bpy)3]2+. The new complexes exhibit a relatively intense emission at room temperature, with lifetimes in the 10-50 ns range, with the homoleptic species exhibiting the higher-energy (maximum at 724 nm) and the longest-lived (τ = 48 ns) emission among the complexes. Luminescence lifetimes and quantum yields are governed by the energy gap law, indicating that direct deactivation to the ground state is the dominant relaxation pathway for 1-6, while thermally activated processes are inefficient. 相似文献
6.
Suresh Rathinasamy Subhas Somalingappa Karki Shiladitya Bhattacharya Lakshmanan Manikandan Senthilkumar G. Prabakaran Malaya Gupta 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):501-507
Bis(1,10-phenanthroline/2,2′-bipyridine) ruthenium(II)complexes containing TCP, TTZ OPBI, and BTSC ligands (where, TCP = 1-thiocarbamoyl-3,5-diphenyl-2-pyrazoline,TTZ = 2-(3,5-diphenyl-4,5-dihydropyrazol-1-yl)-4-phenylthiazole, OPBI = 2-hydroxyphenyl benzimidazole and BTSC = benzoin thiosemicarbazone) have been prepared and characterized. The spectral data suggested that the ligands were coordinated with the metal through nitrogen, sulfur and oxygen atoms. The target complexes were tested in vivo for anticancer activity against transplantable murine tumor cell line, Ehrlich's Ascitic Carcinoma (EAC). All these complexes increased the life span of the EAC-bearing mice, decreased their tumor volume and viable ascitic cell count as well as improved Hb, RBC and WBC counts. These results suggest that the Ru(II) complexes exhibit significant antitumor activity in EAC-bearing mice. It was also observed that the ruthenium complexes protected red blood cells from 2,2′-azo-bis(2-methylpropionamidine) dihydrochloride (AAPH)- induced hemolysis. The inhibitory effect was dose-dependent at a concentration of 20–120 μg/ml. 相似文献
7.
Venugopal Rajendiran Vaiyapuri Subbarayan Periasamy 《Journal of inorganic biochemistry》2010,104(2):217-364
The ‘molecular light switch’ complexes [Ru(bpy)2(dppz)]2+ (1) and [Ru(phen)2(dppz)]2+ (2), where bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline and dppz = dipyrido[3,2-a:2′,3′-c]phenazine, have been explored as probes for diagnosing and staining nuclear components. The phen complex acts as a better staining agent for nonviable cells than for viable cells and exhibits a staining efficiency in tail region of comet more specific and stronger than the already known dye Hoechst 33258. 相似文献
8.
Tetrapodal ligands H4L1 and H4L2 containing imidazole groups have been synthesized by the reaction of 1,10‐phenanthroline‐5,6‐dione with 1,2,4,5‐tetrakis[(4‐formylphenoxy)methyl]benzene and 1,2,4,5‐tetrakis[(3‐formylphenoxy)methyl]benzene, respectively, in presence of NH4OAc. Two star‐shaped complexes [{Ru(bpy)2}4(μ4‐H4L1)](PF6)8 and [{Ru(bpy)2}4(μ4‐H4L2)](PF6)8 (bpy = 2,2′‐bipyridine) have been prepared by refluxing Ru(bpy)2Cl2·2H2O and each ligand in ethylene glycol. The deprotonated complexes [{Ru(bpy)2}4(μ4‐L1)](PF6)4 and [{Ru(bpy)2}4(μ4‐L2)](PF6)4 have been obtained by the reaction of sodium methoxide with [{Ru(bpy)2}4(μ4‐H4L1)](PF6)8 and [{Ru(bpy)2}4(μ4‐H4L2)](PF6)8, respectively, in methanol. The pH effects on the UV–vis light absorption and emission spectra of both complexes have been studied, and ground‐ and excited‐state ionization constants of both complexes have been derived. The photophysical properties of both complexes are strongly dependent on the solution pH. They act as proton‐induced off–on–off luminescent sensors through two successive deprotonation processes of imidazole groups, with a maximum on–off ratio of 8 in buffer solution at room temperature. Theoretical calculations for the highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LOMO) orbitals of bridging ligand are also presented for plausible explanations of the fluorescence changes. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
9.
Jianhua Wang Garry S. Hanan Frédérique Loiseau Sebastiano Campagna 《Inorganica chimica acta》2007,360(3):876-884
A new series of ruthenium(II) complexes, based on 4′-(9-anthryl)-2,2′:6′,2″-terpyridine (an-tpy), have been synthesized from the Ru(III) precursor (an-tpy)RuCl3 (4). These new Ru(II) complexes, [(an-tpy)Ru(tpy-pm-R)] (R = H, 3a; Cl, 3b; phenyl, 3c; p-bromophenyl, 3d), have extended π-conjugation through the 5′-substituted pyrimidyl group, and have been characterized by analytical and spectroscopic methods, and X-ray single crystal structure determination for 3b and 3d. Luminescence lifetime measurements have shown that the anthryl chromophore greatly increases room temperature (r.t.) excited-state lifetime, even though it is not directly connected to the ligand involved in the metal-to-ligand charge transfer (3MLCT) emitting state. This result demonstrates that an equilibrium is established between the anthryl triplet state (3an) and the 3MLCT state even though the two chromophores are physically separated by more than one nanometer. At low temperature in rigid matrix, such equilibrium does not take place and emission arises from both 3an and 3MLCT excited states. The temperature dependence of the excited-state equilibration induces a temperature switch from single (room temperature) to dual (77 K) emission behavior. 相似文献
10.
Kenan Buldurun Nevin Turan Abdulmelik Aras Asim Mantarc Fikret Turkan Ercan Bursal 《化学与生物多样性》2019,16(8)
The new complex compounds [RuLCl(p‐cymene)] ? 3H2O and [NiL2(H2O)2] ? 3H2O (L: 1‐{4‐[(2‐hydroxy‐3‐methoxybenzylidene)amino]phenyl}ethanone) were prepared and characterized using FT‐IR, 1H‐ and 13C‐NMR, mass spectroscopy, TGA, elemental analysis, X‐ray powder diffraction and magnetic moment techniques. Octahedral geometry for new Ni(II) and Ru(II) complexes was proposed. Thermal decomposition confirmed the existence of lattice and coordinated water molecule in the complexes. To determine the antioxidant properties of Schiff base ligand and its Ni(II), Ru(II) metal complexes, FRAP, CUPRAC, ABTS and DPPH methods of antioxidant assays were used. Moreover, enzyme inhibition of complexes was evaluated against carbonic anhydrase I and II isoenzymes (CA I and CA II) and acetylcholinesterase (AChE). For CA I and CA II, the best inhibition enzymes, was the Ni(II) complex with 62.98±18.41, 86.17±23.62 Ki values, whereas this inhibition effect showed ligand with 24.53±2.66 Ki value for the AChE enzyme. 相似文献
11.
Alessio Terenzi Antonio Palumbo Piccionello Annalisa Guarcello 《Inorganica chimica acta》2011,373(1):62-67
The synthesis and structural characterization of NiII, CuII and ZnII complexes of two chelating 1,2,4-oxadiazole ligands, namely 3,5-bis(2′-pyridyl)-1,2,4-oxadiazole (bipyOXA) and 3-(2′-pyridyl)5-(phenyl)-1,2,4-oxadiazole (pyOXA), is here reported. The formed hexacoordinated metal complexes are [M(bipyOXA)2(H2O)2](ClO4)2 and [M(pyOXA)2(ClO4)2], respectively (M = Ni, Cu, Zn). X-ray crystallography, 1H and 13C NMR spectroscopy and C, N, H elemental analysis data concord in attributing them an octahedral coordination geometry. The two coordinated pyOXA ligands assume a trans coplanar disposition, while the two bipyOXA ligands are not. The latter result is a possible consequence of the formation of H-bonds between the coordinated water molecules and the nitrogen atom of the pyridine in position 5 of the oxadiazole ring. The expected splitting of the d metal orbitals in an octahedral ligand field explains the observed paramagnetism of the d8 and d9 electron configuration of the nickel(II) and copper(II) complexes, respectively, as determined by the broadening of their NMR spectra. 相似文献
12.
Palanisamy Uma Maheswari Mallayan Palaniandavar Reji Thomas 《Inorganica chimica acta》2006,359(14):4601-4612
A series of mixed ligand Ru(II) complexes of 5,6-dimethyl-1,10-phenanthroline (5,6-dmp) as primary ligand and 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), pyridine (py) and NH3 as co-ligands have been prepared and characterized by X-ray crystallography, elemental analysis and 1H NMR and electronic absorption spectroscopy. The X-ray crystal structure of the complex [Ru(phen)2(bpy)]Cl2 reveals a distorted octahedral coordination geometry for the RuN6 coordination sphere. The DNA binding constants obtained from the absorption spectral titrations decrease in the order, tris(5,6-dmp)Ru(II) > bis(5,6-dmp)Ru(II) > mono(5,6-dmp)Ru(II), which is consistent with the trend in apparent emission enhancement of the complexes on binding to DNA. These observations reveal that the DNA binding affinity of the complexes depend upon the number of 5,6-dmp ligands and hence the hydrophobic interaction of 5,6-dimethyl groups on the DNA surface, which is critical in determining the DNA binding affinity and the solvent accessibility of the exciplex. Among the bis(5,6-dmp)Ru(II) complexes, those with monodentate py (4) or NH3 (5) co-ligands show DNA binding affinities slightly higher than the bpy and phen analogues. This reveals that they interact with DNA through the co-ligands while both the 5,6-dmp ligands interact with the exterior of the DNA surface. All these observations are supported by thermal denaturation and viscosity measurements. Two DNA binding modes - surface/electrostatic and strong hydrophobic/partial intercalative DNA interaction - are suggested for the mixed ligand complexes on the basis of time-resolved emission measurements. Interestingly, the 5,6-dmp ligands promote aggregation of the complexes on the DNA helix as a helical nanotemplate, as evidenced by induced CD signals in the UV region. The ionic strength variation experiments and competitive DNA binding studies on bis(5,6-dmp)Ru(II) complexes reveal that EthBr and the partially intercalated and kinetically inert [Ru(phen)2(dppz)]2+ (dppz = dipyrido[3,2-a:2′,3′-c]phenazine) complexes revert the CD signals induced by exciton coupling of the DNA-bound complexes with the free complexes in solution. 相似文献
13.
Reaction of the symmetrical proligand H2L with metal(II) acetate and a counteranion to promote crystallisation has given the homodinuclear complexes [Zn2L(OAc)2](BF4)]·2MeOH and [Ni2L(OAc)2](BF4)]·2MeOH the crystal structures of which are reported. These show the presence of a triply bridging (μ-cresolato)bis(μ-carboxylato) dimetal core. 相似文献
14.
Amrita Ghosh 《Inorganica chimica acta》2011,372(1):115-119
Nitrite is quite an abundant anion in the environment. It, however, becomes toxic to human life, as well as aquatic animals when present above the permissible concentration level. We have reported here a Ru(II)-polypyridyl-based complex (1) for chemodosimetric detection of nitrite ion in aqueous solution. Formation of the new triazole based complex, generated by reaction of 1 and N2O3, is ascertained by comparing its properties with a presynthesised triazole complex. 相似文献
15.
Roberto Buscaino Claudia Barolo Michael Grätzel Guido Viscardi 《Inorganica chimica acta》2008,361(3):798-805
We report a mass spectrometric study of ruthenium(II) sensitizer ((C4H9)4N)2[Ru(4-carboxy-4′-carboxylate-2,2′bipyridine)2(NCS)2] (N719) in various organic and aqueous solvents. At the equilibrium different species were found, depending on solution properties. After stoichiometry confirmation through high-resolution mass spectra and isotopic pattern analysis, the formation of these complexes was found to strongly depend from the polarity and the ionic strength of solvent medium. Mass spectra obtained in acetonitrile/tert-butanol (1:1) mixture, used for the absorption of N719 on TiO2, suggests that the main species involved in the adsorption process is the dicarboxylate form of N719 with one (C4H9)4N as counter ion. The photovoltaic data of the N719 sensitizer adsorbed on TiO2 films exhibited a remarkable power conversion efficiency, 11.20% at 1 sun. 相似文献
16.
A novel complex, [Ru(phen)2pzip]2+1 (phen = 1,10-phenanthroline; pzip = 2-(pyrazine-2-yl)imidazo-[4,5-f][1,10]phenanthroline]), has been synthesized and characterized by elemental analysis, ES-MS, 1H NMR. The DNA-binding behaviors of this complex were studied by spectroscopic methods and viscosity measurements. The results indicate that the complex can bind to CT-DNA in an intercalative mode. When irradiated at 365 nm, complex 1 can promote the cleavage of plasmid pBR322DNA. Furthermore, Zn2+ can trigger the DNA cleavage of complex 1 without irradiation. The mechanism studies revealed that the DNA cleavage by complex 1 in the presence of Zn2+ is likely to proceed via a hydrolytic cleavage process. 相似文献
17.
Kotha Laxma Reddy Y. Harish Kumar Reddy S. Satyanarayana 《Nucleosides, nucleotides & nucleic acids》2013,32(10):953-968
Four Ru(II) polypyridyl complexes, [Ru(bpy)2(7-NO2-dppz)]2+, [Ru(bpy)2(7-CH3-dppz)]2+, [Ru(phen)2(7-NO2-dppz)]2+, and [Ru(phen)2(7-CH3-dppz)]2+ (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline), (7-Nitro-dppz = 7-Nitro dipyrido[3,2-a:2′-3′-c]phenazine, 7-CH3-dppz = 7-Methyl dipyrido[3,2-a:2′-3′-c]phenazine), have been synthesized and characterized by IR, UV, elemental analysis, 1H NMR, 13C-NMR, and mass spectroscopy. The DNA-binding properties of the four complexes were investigated by spectroscopic and viscosity measurements. The results suggest that all four complexes bind to DNA via an intercalative mode. Under irradiation at 365 nm, all four complexes were found to promote the photocleavage of plasmid pBR 322 DNA. Toxicological effects of the selected complexes were performed on industrially important yeasts (eukaryotic microorganisms). 相似文献
18.
A novel Ru(III) complex, mer-[RuCl(3)(CH(3)CN)(dpq)] (1), has been synthesized and characterized by X-ray diffraction, where dpq=dipyrido[3,2-d:2',3'-f]quinoxaline. Its chemical and biological properties have been intensively compared with those of mer-[RuCl(3)(DMSO)(dpq)] (DMSO=dimethyl sulfoxide) (2). It has been found that the stability in buffered solutions and the reduction potential for the Ru(III)/Ru(II) couple can be modulated by changing the small molecule bonded to the Ru(III) center. Interactions of 1 with DNA have been investigated by DNA melting experiments, DNA competitive binding with EB (ethidium bromide), plasmid DNA cleavage experiments and viscosity measurements. The interaction of 1 and 2 with BSA (bovine serum albumin) has also been studied using fluorescent quenching method. The experimental results show that 1 exerts higher affinity towards DNA and BSA than 2 does. The cytotoxicity of 1 has been evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method, and 2 shows slightly higher anticancer potency than 1 does against all the cell lines screened. Attempts are made to clarify the possible antitumor mechanisms of these two complexes by analyzing the experimental results presented. 相似文献
19.
Jing Han 《Inorganica chimica acta》2006,359(1):99-108
Four novel Mo(II) and Rh(II) complexes with cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene (cis-dbe) or closed-dbe were synthesized and characterized. Employing [M(O2CCF3)4] (M = Mo, Rh) with cis-dbe or closed-dbe afforded complex [Mo2(O2CCF3)4(cis-dbe)](benzene) (1), [Rh2(O2CCF3)4(cis-dbe)](benzene) (2), [{Mo2(O2CCF3)4}2(closed-dbe)] (3), and [Rh2(O2CCF3)4(closed-dbe)](p-xylene) (4). The structures of four metal complexes were revealed by X-ray crystallographic analyses and the correlation between the crystal structures and the photochromic performance was discussed. In all complexes, two cyano groups of the ligand bridged two dimetal carboxylates to give a 1-D zigzag infinite chain structure. Upon irradiation with 405 nm light, complex 1 turned into reddish purple from yellow, and the color reverted to initial yellow on exposure to 563 nm light, indicating the reversible cyclization/ring-opening reaction in the crystalline phase. However, the Rh(II) complex 2 did not display similarities in reaction induced by light, which is attributable to the lower ratio of photoactive anti-parallel conformers compared with complex 1 and coordination effect of metal ions on photochromism of diarylethenes. The complexes of Rh(II) ions did not exhibit the expected reversible photoinduced behavior. 相似文献
20.
A series of Pt(II) complexes containing 1,2-diphenylethylenediamine (stien) isomers were synthesized and tested for their antitumor activity against leukemia L1210. Among the Pt(II) complexes examined water-soluble Pt(II) complexes with sulfate, nitrate and D-glucuronate ions as leaving groups exhibited relatively high antitumor activity. Furthermore, the interactions between calf-thymus DNA and Pt(SO4) (stein) complexes were investigated by means of circular dichroism spectrometry. Dichroism enhancements observed in the interaction between DNA and Pt(SO4) (stien) complexes were analysed to be contributable to two factors: (1) vicinal effects of DNA on the d-d transitions of Pt(II) ions and (2) conformational changes of DNA caused by the coordination of cis-configurational Pt(II) complexes. 相似文献