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1.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(41):12802-12807
Using a new mononuclear “building block,” for the first time, a dinuclear RuII(dppn) complex and a heteroleptic system containing both RuII(dppz) and RuII(dppn) moieties are reported. The complexes, including the mixed dppz/dppn system, are 1O2 sensitizers. However, unlike the homoleptic dppn systems, the mixed dppz/dppn complex also displays a luminescence “switch on” DNA light‐switch effect. In both cisplatin sensitive and resistant human ovarian carcinoma lines the dinuclear complexes show enhanced uptake compared to their mononuclear analogue. Thanks to a favorable combination of singlet oxygen generation and cellular uptake properties all three of the new complexes are phototoxic and display potent activity against chemotherapeutically resistant cells. 相似文献
2.
Tuning the Excited State of Water‐Soluble IrIII‐Based DNA Intercalators that are Isostructural with [RuII(NN)2(dppz)] Light‐Switch Complexes 下载免费PDF全文
Sasha Stimpson Dan R. Jenkinson Andrew Sadler Dr. Mark Latham Dr Ashley Wragg Dr. Anthony J. H. M. Meijer Dr. Jim A. Thomas 《Angewandte Chemie (International ed. in English)》2015,54(10):3000-3003
The synthesis of two new IrIII complexes which are effectively isostructural with well‐established [Ru(NN)2(dppz)]2+ systems is reported (dppz=dipyridophenazine; NN=2,2′‐bipyridyl, or 1,10‐phenanthroline). One of these IrIII complexes is tricationic and has a conventional N6 coordination sphere. The second dicationic complex has a N5C coordination sphere, incorporating a cyclometalated analogue of the dppz ligand. Both complexes show good water solubility. Experimental and computational studies show that the photoexcited states of the two complexes are very different from each other and also differ from their RuII analogues. Both of the complexes bind to duplex DNA with affinities that are two orders of magnitude higher than previously reported Ir(dppz)‐based systems and are comparable with RuII(dppz) analogues. 相似文献
3.
Ruthenium Complex “Light Switches” that are Selective for Different G‐Quadruplex Structures 下载免费PDF全文
Erin Wachter Diego Moyá Dr. Sean Parkin Dr. Edith C. Glazer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):550-559
Recognition and regulation of G‐quadruplex nucleic acid structures is an important goal for the development of chemical tools and medicinal agents. The addition of a bromo‐substituent to the dipyridylphenazine (dppz) ligands in the photophysical “light switch”, [Ru(bpy)2dppz]2+, and the photochemical “light switch”, [Ru(bpy)2dmdppz]2+, creates compounds with increased selectivity for an intermolecular parallel G‐quadruplex and the mixed‐hybrid G‐quadruplex, respectively. When [Ru(bpy)2dppz‐Br]2+ and [Ru(bpy)2dmdppz‐Br]2+ are incubated with the G‐quadruplexes, they have a stabilizing effect on the DNA structures. Activation of [Ru(bpy)2dmdppz‐Br]2+ with light results in covalent adduct formation with the DNA. These complexes demonstrate that subtle chemical modifications of RuII complexes can alter G‐quadruplex selectivity, and could be useful for the rational design of in vivo G‐quadruplex probes. 相似文献
4.
Dr. Eszter M. Nagy Andrea Pettenuzzo Giulia Boscutti Prof. Dr. Luciano Marchiò Prof. Dr. Lisa Dalla Via Prof. Dr. Dolores Fregona 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(45):14464-14472
Hereby we present the synthesis of several ruthenium(II) and ruthenium(III) dithiocarbamato complexes. Proceeding from the Na[trans‐RuIII(dmso)2Cl4] ( 2 ) and cis‐[RuII(dmso)4Cl2] ( 3 ) precursors, the diamagnetic, mixed‐ligand [RuIIL2(dmso)2] complexes 4 and 5 , the paramagnetic, neutral [RuIIIL3] monomers 6 and 7 , the antiferromagnetically coupled ionic α‐[RuIII2L5]Cl complexes 8 and 9 as well as the β‐[RuIII2L5]Cl dinuclear species 10 and 11 (L=dimethyl‐ (DMDT) and pyrrolidinedithiocarbamate (PDT)) were obtained. All the compounds were fully characterised by elemental analysis as well as 1H NMR and FTIR spectroscopy. Moreover, for the first time the crystal structures of the dinuclear β‐[RuIII2(dmdt)5]BF4 ? CHCl3 ? CH3CN and of the novel [RuIIL2(dmso)2] complexes were also determined and discussed. For both the mono‐ and dinuclear RuII and RuIII complexes the central metal atoms assume a distorted octahedral geometry. Furthermore, in vitro cytotoxicity of the complexes has been evaluated on non‐small‐cell lung cancer (NSCLC) NCI‐H1975 cells. All the mono‐ and dinuclear RuIII dithiocarbamato compounds (i.e., complexes 6 – 10 ) show interesting cytotoxic activity, up to one order of magnitude higher with respect to cisplatin. Otherwise, no significant antiproliferative effect for either the precursors 2 and 3 or the RuII complexes 4 and 5 has been observed. 相似文献
5.
Ruthenium‐Containing Linear Helicates and Mesocates with Tuneable p53‐Selective Cytotoxicity in Colorectal Cancer Cells 下载免费PDF全文
Dr. Simon J. Allison Dr. David Cooke Francesca S. Davidson Prof. Paul I. P. Elliott Dr. Robert A. Faulkner Hollie B. S. Griffiths Owen J. Harper Omar Hussain Prof. P. Jane Owen‐Lynch Prof. Roger M. Phillips Prof. Craig R. Rice Samantha L. Shepherd Dr. Richard T. Wheelhouse 《Angewandte Chemie (International ed. in English)》2018,57(31):9799-9804
The ligands L1 and L2 both form separable dinuclear double‐stranded helicate and mesocate complexes with RuII. In contrast to clinically approved platinates, the helicate isomer of [Ru2( L1 )2]4+ was preferentially cytotoxic to isogenic cells (HCT116 p53?/?), which lack the critical tumour suppressor gene. The mesocate isomer shows the reverse selectivity, with the achiral isomer being preferentially cytotoxic towards HCT116 p53+/+. Other structurally similar RuII‐containing dinuclear complexes showed very little cytotoxic activity. This study demonstrates that alterations in ligand or isomer can have profound effects on cytotoxicity towards cancer cells of different p53 status and suggests that selectivity can be “tuned” to either genotype. In the search for compounds that can target difficult‐to‐treat tumours that lack the p53 tumour suppressor gene, [Ru2( L1 )2]4+ is a promising compound for further development. 相似文献
6.
Controlling the Direction of the Molecular Axis of Rod‐Shaped Binuclear Ruthenium Complexes on Single‐Walled Carbon Nanotubes 下载免费PDF全文
Dr. Hiroaki Ozawa Kazuma Kosaka Tomomi Kita Kai Yoshikawa Prof. Dr. Masa‐aki Haga 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6575-6582
We report the synthesis of a mixed‐valence ruthenium complex, bearing pyrene moieties on one side of the ligands as anchor groups. Composites consisting of mixed‐valence ruthenium complexes and SWNTs were prepared by noncovalent π–π interactions between the SWNT surface and the pyrene anchors of the Ru complex. In these composites, the long axis of the Ru complexes was aligned in parallel to the principal direction of the SWNT. The optimized conformation of these complexes on the SWNT surface was calculated by molecular mechanics. The composites were examined by UV/Vis absorption and FT‐IR spectroscopy, XPS, and SEM analysis. Furthermore, their electrochemical properties were evaluated. Cyclic voltammograms of the composites showed reversible oxidation waves at peak oxidation potentials (Epox) = 0.86 and 1.08 V versus Fc+/Fc, which were assigned to the RuII‐RuII/RuII‐RuIII and the RuII‐RuIII/RuIII‐RuIII oxidation events of the dinuclear ruthenium complex, respectively. Based on these observations, we concluded that the electrochemical properties and mixed‐valence state of the dinuclear ruthenium complexes were preserved upon attachment to the SWNT surface. 相似文献
7.
Qian‐Xiong Zhou Dr. Wan‐Hua Lei Jing‐Rong Chen Chao Li Yuan‐Jun Hou Xue‐Song Wang Prof. Bao‐Wen Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(10):3157-3165
Ruthenium(II) polypyridyl complexes with long‐wavelength absorption and high singlet‐oxygen quantum yield exhibit attractive potential in photodynamic therapy. A new heteroleptic RuII polypyridyl complex, [Ru(bpy)(dpb)(dppn)]2+ (bpy=2,2′‐bipyridine, dpb=2,3‐bis(2‐pyridyl)benzoquinoxaline, dppn=4,5,9,16‐tetraaza‐dibenzo[a,c]naphthacene), is reported, which exhibits a 1MLCT (MLCT: metal‐to‐ligand charge transfer) maximum as long as 548 nm and a singlet‐oxygen quantum yield as high as 0.43. Steady/transient absorption/emission spectra indicate that the lowest‐energy MLCT state localizes on the dpb ligand, whereas the high singlet‐oxygen quantum yield results from the relatively long 3MLCT(Ru→dpb) lifetime, which in turn is the result of the equilibrium between nearly isoenergetic excited states of 3MLCT(Ru→dpb) and 3ππ*(dppn). The dppn ligand also ensures a high binding affinity of the complex towards DNA. Thus, the combination of dpb and dppn gives the complex promising photodynamic activity, fully demonstrating the modularity and versatility of heteroleptic RuII complexes. In contrast, [Ru(bpy)2(dpb)]2+ shows a long‐wavelength 1MLCT maximum (551 nm) but a very low singlet‐oxygen quantum yield (0.22), and [Ru(bpy)2(dppn)]2+ shows a high singlet‐oxygen quantum yield (0.79) but a very short wavelength 1MLCT maximum (442 nm). 相似文献
8.
Wuyang Hua Dr. Gang Xu Dr. Jian Zhao Dr. Z. Wang Jiapeng Lu Prof. Wenfang Sun Prof. Shaohua Gou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(72):17495-17503
Subtle ligand modifications on RuII-polypyridyl complexes may result in different excited-state characteristics, which provides the opportunity to tune their photo-physicochemical properties and subsequently change their biological functions. Here, a DNA-targeting RuII-polypyridyl complex (named Ru1 ) with highly photosensitizing 3IL (intraligand) excited state was designed based on a classical DNA-intercalator [Ru(bpy)2(dppz)] ⋅ 2 PF6 by incorporation of the dppz (dipyrido[3,2-a:2′,3′-c]phenazine) ligand tethered with a pyrenyl group, which has four orders of magnitude higher potency than the model complex [Ru(bpy)2(dppz)] ⋅ 2 PF6 upon light irradiation. This study provides a facile strategy for the design of organelle-targeting RuII-polypyridyl complexes with dramatically improved photobiological activity. 相似文献
9.
Presented herein is a set of bimetallic and trimetallic “coordination booster‐catalyst” assemblies in which the coordination complexes [RuII(terpy)2] and [OsII(terpy)2] acted as boosters for enhancement of the catalytic activity of [RuII(NHC)(para‐cymene)]‐based catalytic site. The boosters accelerated the oxidative loss of para‐cymene from the catalytic site to generate the active catalyst during the oxidation of alkenes and alkynes into corresponding aldehydes, ketones and diketones. It was found that the boosting efficiency of the [OsII(terpy)2] units was considerably higher than its congener [RuII(terpy)2] unit in these assemblies. Mechanistic studies were conducted to understand this unique improvement. 相似文献
10.
T. N. Kropacheva V. I. Kornev D. A. Loginov V. I. Meshcheryakov E. V. Mutseneck D. V. Muratov D. S. Perekalin L. S. Shul’pina A. R. Kudinov 《Russian Chemical Bulletin》2005,54(10):2354-2358
New dinuclear ruthenium manganese complexes of general composition (bpy)2Ru(L)MnClx(H2O)2 (L is 1,10-phenanthroline-5,6-dione, 3,3′-dicarboxy-2,2′-bipyridyl, or bis(pyrazolyl); x = 2 or 4) were synthesized by the reaction of (bpy)2Ru(L) with MnCl2 · 4H2O. These compounds and the starting mononuclear ruthenium complexes were studied by spectrophotometric and electrochemical
methods in MeCN. The position of the charge-transfer band RuII → L in the spectra depends on the donor-acceptor characteristics of the ligand L. For the dinuclear complex under study,
the formal potentials of reversible one-electron oxidation of RuII are in the range of 0.9–1.2 V (vs. the standard hydrogen electrode), whereas oxidation of MnII occurs at more positive (by 0.1–0.2 V) potentials.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2281–2285, October, 2005. 相似文献
11.
Thread Insertion of a Bis(dipyridophenazine) Diruthenium Complex into the DNA Double Helix by the Extrusion of AT Base Pairs and Cross‐Linking of DNA Duplexes 下载免费PDF全文
D. Roeland Boer Lisha Wu Per Lincoln Miquel Coll 《Angewandte Chemie (International ed. in English)》2014,53(7):1949-1952
The crystal structure of the Δ,Δ enantiomer of the binuclear “light‐switch” ruthenium complex [μ‐(11,11′‐bidppz)(1,10‐phenanthroline)4 Ru2]4+ bound to the oligonucleotide d(CGTACG) shows that one dppz moiety of the dumbbell‐like compound inserts into the DNA stack through the extrusion of an AT base pair. The second dppz moiety recruits a neighboring DNA molecule, and the complex thus cross‐links two adjacent duplexes by bridging their major grooves. 相似文献
12.
Andrs Zelcer Zulema D. Chaia Fabio D. Cukiernik Oscar E. Piro Eduardo E. Castellano 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):m144-m146
The title compound, catena‐poly[[tetrakis(μ‐decanoato‐κ2O:O′)diruthenium(II,III)(Ru—Ru)]‐μ‐octanesulfonato‐κ2O:O′], [Ru2(C10H19O2)4(C8H17O3S)], is an octanesulfonate derivative of the mixed‐valence complex diruthenium tetradecanoate. The equatorial carboxylate ligands are bidentate, bridging two Ru atoms to form a dinuclear structure. Each of the two independent dinuclear metal complexes in the asymmetric unit is located at an inversion centre. The octanesulfonate anion bridges the two dinuclear units through axial coordination. The alkyl chains of the carboxylate and sulfonate ligands are arranged in a parallel manner. The global structure can be seen as infinite chains of polar moieties separated by a double layer of non‐polar alkyl groups, without interdigitation of the alkyl chains. 相似文献
13.
Ketimido Metallophthalocyanines: An Approach to Phthalocyanine‐Supported Mononuclear High‐Valent Ruthenium Complexes 下载免费PDF全文
Dr. Jie‐Sheng Huang Dr. Kwok‐Ming Wong Dr. Sharon Lai‐Fung Chan Ken Chi‐Hang Tso Tao Jiang Prof. Dr. Chi‐Ming Che 《化学:亚洲杂志》2014,9(1):338-350
A “metal–ketimine+ArI(OR)2” approach has been developed for preparing metal–ketimido complexes, and ketimido ligands are found to stabilize high‐valent metallophthalocyanine (M? Pc) complexes such as ruthenium(IV) phthalocyanines. Treatment of bis(ketimine) ruthenium(II) phthalocyanines [RuII(Pc)(HN?CPh2)2] ( 1a ) and [RuII(Pc)(HNQu)2] ( 1b ; HNQu=N‐phenyl‐1,4‐benzoquinonediimine) with PhI(OAc)2 affords bis(ketimido) ruthenium(IV) phthalocyanines [RuIV(Pc)(N?CPh2)2] ( 2a ) and [RuIV(Pc)(NQu)2] ( 2b ), respectively. X‐ray crystal structures of 1b and [RuII(Pc)(PhN?CHPh)2] ( 1c ) show Ru? N(ketimine) distances of 2.075(4) and 2.115(3) Å, respectively. Complexes 2a , 2b readily revert to 1a , 1b upon treatment with phenols. 1H NMR spectroscopy reveals that 2a , 2b are diamagnetic and 2b exists as two isomers, consistent with a proposed eclipsed orientation of the ketimido ligands in these ruthenium(IV) complexes. The reaction of 1a , 1b with PhI(OAc)2 to afford 2a , 2b suggests the utility of ArI(OR)2 as an oxidative deprotonation agent for the generation of high‐valent metal complexes featuring M? N bonds with multiple bonding characters. DFT and time‐dependent (TD)‐DFT calculations have been performed on the electronic structures and the UV/Vis absorption spectra of 1b and 2b , which provide support for the diamagnetic nature of 2b and reveal a significant barrier for rotation of the ketimido group about the Ru? N(ketimido) bond. 相似文献
14.
The basic aqueous coordination chemistry of RuII has been studied using the catalytically important TPPTS phosphine (TPPTS=trisodium salt of 3,3′,3″‐phosphinetriylbenzenesulfonic acid) and small gas molecules (H2, CO, N2) as ligands. As a result, new water‐soluble ruthenium mixed hydride complexes, presumably key species in many industrial catalytic processes, have been formed and identified. The RuII mixed hydrides were synthesized, and their formation was followed in situ by multinuclear NMR spectroscopy, pressurizing aqueous RuII? TPPTS systems with H2 and CO gas in sapphire NMR tubes. The formation equilibrium of these complexes is highly dependant on the temperature and the gas pressures. Under 50 atm of N2, the unique [RuH(CO)(N2)(TPPTS)2(H2O)]+ complex has been identified, which could be the first step toward dinitrogen activation. 相似文献
15.
The reaction of 2,2′:4,4′′:4′,4′′′‐quaterpyridyl (qtpy), with d6 ruthenium(II) (RuII), and rhenium(I) (ReI) metal centers has been investigated. The pendant pyridyl groups on the products have also been methylated to produce a second series of complexes containing coordinated Meqtpy2+. The absorption spectra of the complexes are dominated by intraligand and charge‐transfer bands. The ruthenium(II) complexes display broad unstructured luminescence consistent with emission from a Ru(d)→diimine(π*) manifold in acetonitrile solutions. In aqueous solutions, their emissions are weaker and the lifetimes are shorter. This effect is particularly acute for complexes incorporating coordinated dipyridylpyrazine, dppz, ligands. Although the emission of the ruthenium(II) complexes containing Meqtpy2+ is generally shorter than their qtpy analogs, it is notable that solvent‐dependent effects are much less intense. The rhenium(I) complexes also display broad unstructured luminescence but, compared with the ruthenium(II) systems, they have a relatively short lifetime in acetonitrile. Electrochemical studies reveal that all of the RuII complexes display chemically reversible metal‐based oxidations. ReI complexes only display irreversible metal‐based oxidations. In most cases, the reduction processes were not fully chemically reversible. The electrochemical and optical studies reveal that the nature of the lowest excited state of these complexes—particularly, the systems incorporating dppz—is highly dependent on the nature of the coordinated ligands. Calculations indicate that, although the excited state of most of the complexes is centered on the qtpy or Meqtpy2+ ligands, the excited state of the complexes containing dppz ligands is switched away from the dppz by qtpy methylation. A crystallographic study on one of the dicationic ruthenium(II) structures reveals that it forms an inclusion complex with benzene. 相似文献
16.
The complex cis‐[RuIII(dmbpy)2Cl2](PF6) ( 2 ) (dmbpy = 4, 4′‐dimethyl‐2, 2′‐bipyridine) was obtained from the reaction of cis‐[RuII(dmbpy)2Cl2] ( 1 ) with ammonium cerium(IV) nitrate followed by precipitation with saturated ammonium hexafluoridophosphate. The 1H NMR spectrum of the RuIII complex confirms the presence of paramagnetic metal atoms, whereas that of the RuII complex displays diamagnetism. The 31P NMR spectrum of the RuIII complex shows one signal for the phosphorus atom of the PF6– ion. The perspective view of each [RuII/III(dmbpy)2Cl2]0/+ unit manifests that the ruthenium atom is in hexacoordinate arrangement with two dmbpy ligands and two chlorido ligands in cis position. As the oxidation state of the central ruthenium metal atom becomes higher, the average Ru–Cl bond length decreases whereas the Ru–N (dmbpy) bond length increases. The cis‐positioned dichloro angle in RuIII is 1.3° wider than that in the RuII. The dihedral angles between pair of planar six‐membered pyridyl ring in the dmbpy ligand for the RuII are 4.7(5)° and 5.7(4)°. The observed inter‐planar angle between two dmbpy ligands in the RuII is 89.08(15)°, whereas the value for the RuIII is 85.46(20)°. 相似文献
17.
Dr. Wilson D. Bailey Alexander S. Phearman Dr. Lapo Luconi Dr. Andrea Rossin Prof. Dmitry G. Yakhvarov Dr. Lucia D'Accolti Dr. Sarah E. Flowers Dr. Werner Kaminsky Prof. Richard A. Kemp Dr. Giuliano Giambastiani Prof. Karen I. Goldberg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(42):9920-9929
The hydrogenolysis of mono- and dinuclear PdII hydroxides was investigated both experimentally and computationally. It was found that the dinuclear μ-hydroxide complexes {[(PCNR)Pd]2(μ-OH)}(OTf) (PCNH=1-[3-[(di-tert-butylphosphino)methyl]phenyl]-1H-pyrazole; PCNMe=1-[3-[(di-tert-butylphosphino)methyl]phenyl]-5-methyl-1H-pyrazole) react with H2 to form the analogous dinuclear hydride species {[(PCNR)Pd]2(μ-H)}(OTf). The dinuclear μ-hydride complexes were fully characterized, and are rare examples of structurally characterized unsupported singly bridged μ-H PdII dimers. The {[(PCNMe)Pd]2(μ-OH)}(OTf) hydrogenolysis mechanism was investigated through experiments and computations. The hydrogenolysis of the mononuclear complex (PCNH)Pd-OH resulted in a mixed ligand dinuclear species [(PCNH)Pd](μ-H)[(PCC)Pd] (PCC=a dianionic version of PCNH bound through phosphorus P, aryl C, and pyrazole C atoms) generated from initial ligand “rollover” C−H activation. Further exposure to H2 yields the bisphosphine Pd0 complex Pd[(H)PCNH]2. When the ligand was protected at the pyrazole 5-position in the (PCNMe)Pd−OH complex, no hydride formed under the same conditions; the reaction proceeded directly to the bisphosphine Pd0 complex Pd[(H)PCNMe]2. Reaction mechanisms for the hydrogenolysis of the monomeric and dimeric hydroxides are proposed. 相似文献
18.
Marek B. Majewski Dr. Norma R. de Tacconi Prof. Frederick M. MacDonnell Prof. Michael O. Wolf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(25):8331-8341
RuII complexes incorporating both amide‐linked bithiophene donor ancillary ligands and laminate acceptor ligands; dipyrido[3,2‐a:2′,3′‐c]phenazine (dppz), tetrapyrido[3,2‐a:2′,3′‐c:3′′,2′′‐h:2′′′,3′′′‐j]phenazine (tpphz), and 9,11,20,22‐tetraazatetrapyrido[3,2‐a:2′,3′‐c:3′′,2′′‐l:2′′′,3′′′]‐pentacene (tatpp) exhibit long‐lived charge separated (CS) states, which have been analyzed using time‐resolved transient absorption (TA), fluorescence, and electronic absorption spectroscopy in addition to ground state electrochemical and spectroelectrochemical measurements. These complexes possess two electronically relevant 3MLCT states related to electron occupation of MOs localized predominantly on the proximal “bpy‐like” portion and central (or distal) “phenazine‐like” portion of the acceptor ligand as well as energetically similar 3LC and 3ILCT states. The unusually long excited state lifetimes (τ up to 7 μs) observed in these complexes reflect an equilibration of the 3MLCTprox or 3MLCTdist states with additional triplet states, including a 3LC state and a 3ILCT state that formally localizes a hole on the bithiophene moiety and an electron on the laminate acceptor ligand. Coordination of a ZnII ion to the open coordination site of the laminate acceptor ligand is observed to significantly lower the energy of the 3MLCTdist state by decreasing the magnitude of the excited state dipole and resulting in much shorter excited state lifetimes. The presence of the bithiophene donor group is reported to substantially extend the lifetime of these Zn adducts via formation of a 3ILCT state that can equilibrate with the 3MLCTdist state. In tpphz complexes, ZnII coordination can reorder the energy of the 3MLCTprox and 3MLCTdist states such that there is a distinct switch from one state to the other. The net result is a series of complexes that are capable of forming CS states with electron–hole spatial separation of up to 14 Å and possess exceptionally long lifetimes by equilibration with other triplet states. 相似文献
19.
Christopher S. Wilson Dr. Timothy J. Prior Dr. Jordon Sandland Huguette Savoie Prof. Ross W. Boyle Dr. Benjamin S. Murray 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(50):11593-11603
Dinuclear metallodrugs offer much potential in the development of novel anticancer chemotherapeutics as a result of the distinct interactions possible with bio-macromolecular targets and the unique biological activity that can result. Herein, we describe the development of isostructural homo-dinuclear OsII–OsII and hetero-dinuclear OsII–RuII organometallic complexes formed from linking the arene ligands of [M(η6-arene)(C2O4)(PTA)] units (M=Os/Ru; PTA=1,3,5-triaza-7-phosphaadamantane). Using these complexes together with the known RuII–RuII analogue, a chromatin-modifying agent, we probed the impact of varying the metal ions on the structure, reactivity and biological activity of these complexes. The complexes were structurally characterised by X-ray diffraction experiments, their stability and reactivity were examined by using 1H and 31P NMR spectroscopy, and their biological activity was assessed, alongside that of mononuclear analogues, through MTT assays and cell-cycle analysis (HT-29 cell line). The results revealed high antiproliferative activity in each case, with cell-cycle profiles of the dinuclear complexes found to be similar to that for untreated cells, and similar but distinct profiles for the mononuclear complexes. These results indicate these complexes impact on cell viability predominantly through a non-DNA-damaging mechanism of action. The new OsII–OsII and OsII–RuII complexes reported here are further examples of a family of compounds operating via mechanisms of action atypical of the majority of metallodrugs, and which have potential as tools in chromatin research. 相似文献
20.
Reaction of five N,N′-bis(aryl)pyridine-2,6-dicarboxamides (H2L-R, where H2 denotes the two acidic protons and R (R = OCH3, CH3, H, Cl and NO2) the para substituent in the aryl fragment) with [Ru(trpy)Cl3](trpy = 2,2′,2″-terpyridine) in refluxing ethanol in the presence of a base (NEt3) affords a group of complexes of the type [RuII(trpy)(L-R)], each of which contains an amide ligand coordinated to the metal center as a dianionic tridentate N,N,N-donor along with a terpyridine ligand. Structure of the [RuII(trpy)(L-Cl)] complex has been determined by X-ray crystallography. All the Ru(II) complexes are diamagnetic, and show characteristic 1H NMR signals and intense MLCT transitions in the visible region. Cyclic voltammetry on the [RuII(trpy)(L-R)] complexes shows a Ru(II)–Ru(III) oxidation within 0.16–0.33 V versus SCE. An oxidation of the coordinated amide ligand is also observed within 0.94–1.33 V versus SCE and a reduction of coordinated terpyridine ligand within −1.10 to −1.15 V versus SCE. Constant potential coulometric oxidation of the [RuII(trpy)(L-R)] complexes produces the corresponding [RuIII(trpy)(L-R)]+ complexes, which have been isolated as the perchlorate salts. Structure of the [RuIII(trpy)(L-CH3)]ClO4 complex has been determined by X-ray crystallography. All the Ru(III) complexes are one-electron paramagnetic, and show anisotropic ESR spectra at 77 K and intense LMCT transitions in the visible region. A weak ligand-field band has also been shown by all the [RuIII(trpy)(L-R)]ClO4 complexes near 1600 nm. 相似文献