Robust Tris‐Cyclometalated Iridium(III) Phosphors with Ligands for Effective Charge Carrier Injection/Transport: Synthesis,Redox, Photophysical,and Electrophosphorescent Behavior

With the target to design and develop new functionalized green triplet light emitters that possess distinctive electronic properties for robust and highly efficient phosphorescent organic light‐emitting diodes (PHOLEDs), a series of bluish–green to yellow–green phosphorescent tris‐cyclometalated homoleptic iridium(III) complexes [Ir(ppy‐X)₃] (X=SiPh₃, GePh₃, NPh₂, POPh₂, OPh, SPh, SO₂Ph, Hppy=2‐phenylpyridine) have been synthesized and fully characterized by spectroscopic, redox, and photophysical methods. By chemically manipulating the lowest triplet‐state character of Ir(ppy)₃ with some functional main‐group 14–16 moieties on the phenyl ring of ppy, a new family of metallophosphors with high‐emission quantum yields, short triplet‐state lifetimes, and good hole‐injection/hole‐transporting or electron‐injection/electron‐transporting properties can be obtained. Remarkably, all of these Ir^III complexes show outstanding electrophosphorescent performance in multilayer doped devices that surpass that of the state‐of‐the‐art green‐emitting dopant Ir(ppy)₃. The devices described herein can reach the maximum external quantum efficiency (η_ext) of 12.3 %, luminance efficiency (η_L) of 50.8 cd A^?1, power efficiency (η_p) of 36.9 Lm W^?1 for [Ir(ppy‐SiPh₃)₃], 13.9 %, 60.8 cd A^?1, 49.1 Lm W^?1 for [Ir(ppy‐NPh₂)₃], and 10.1 %, 37.6 cd A^?1, 26.1 Lm W^?1 for [Ir(ppy‐SO₂Ph)₃]. These results provide a completely new and effective strategy for carrier injection into the electrophosphor to afford high‐performance PHOLEDs suitable for various display applications.     

Cyclometallated iridium(III) complexes with substituted 1,10-phenanthrolines: a new class of highly active organometallic second order NLO-phores with excellent transparency with respect to second harmonic emission

[Ir(ppy)(2)(5-R-1,10-phen)][PF(6)] (ppy = cyclometallated 2-phenylpyridine, phen = phenanthroline, R = H, Me, NMe(2), NO(2)) and [Ir(ppy)(2)(4-R',7-R'-1,10-phen)][PF(6)] (R' = Me, Ph) complexes are characterized by one of the highest second order NLO response (measured by the EFISH technique) reported for a metal complex, mainly due (as suggested by a theoretical SOS-TDDFT investigation) to MLCT processes from the ppy-Ir based moiety acting as donor push system to pi* orbitals of phen, acting as an acceptor pull system; the good transparency to the second harmonic emission renders these NLO-phores appealing as building blocks for molecular materials with second harmonic generation.     

Synthesis,Characterization and Magnetic Studies of μ‐Oxamido Copper (II) ‐ Chromium (III) Heterodinuclear Complexes

Three new μ‐oxamido‐bridged heterodinuclear copper (II)‐chromium (III) complexes formulated [Cu(Me₂oxpn)Cr‐(L)₂](NO₃)₃, where Me₂oxpn denotes N,N'‐bis(3‐amino‐2, 2‐dimethylpropyl)oxamido dianion and L represents 5‐methyl‐1,10‐phenanthroline (Mephen), 4,7‐diphenyl‐1,10‐phenanthroline (Ph₂phen) or 2,2′‐bipyridine (bpy), have been synthesized and characterized by elemental analyses, IR and electronic spectral studies, magnetic moments of room‐temperature and molar conductivity measurements. It is proposed that these complexes have oxamido‐bridged structures consisting of planar copper (II) and octahedral chromium (III) ions. The variable temperature magnetic susceptibilities (4.2–300 K) of complexes [Cu(Me₂oxpn)Cr(Ph₂phen)₂](NO₃)₃ (1) and [Cu(Me₂oxpn)Cr(Mephen)₂] (NO₃)₃ (2) were further measured and studied, demonstrating the ferromagnetic interaction between the adjacent chromium (III) and copper (II) ions through the oxamido‐bridge in both complexes 1 and 2. Based on the spin Hamiltonian, ? = ‐ 2J?₁ · ?₂, the exchange integrals J were evaluated as + 21.5 an^?1 for 1 and + 22.8 cm^?1 for 2.     

Theoretical studies of ground and excited electronic states in a series of heteroleptic iridium complexes using density functional theory

A series of new heteroleptic iridium(III) complexes [Ir(C^?N)₂(N^?N)]PF₆ ( 1 ‐ 6 ) (each with two cyclometalating C^?N ligands and one neutral N^?N ancillary ligand, where C^?N = 2‐phenylpyridine (ppy), 5‐methyl‐2‐(4‐fluoro)phenylpyridine (F‐mppy), and N^?N = 2,2′‐dipyridyl (bpy), 1,10‐phenanthroline (phen), 4,4′‐diphenyl‐2,2′‐dipyridy (dphphen) were found to have rich photophysical properties. Theoretical calculations are employed for studying the photophysical and electrochemical properties. All complexes are investigated using density functional theory. Excited singlet and triplet states are examined using time‐dependent density functional theory. The low‐lying excited‐state geometries are optimized at the ab initio configuration interaction singles level. Then, the excited‐state properties are investigated in detail, including absorption and emission properties, photoactivation processes. The excited state of complexes is complicated and contains triplet metal‐to‐ligand charge transfer, triplet ligand‐to‐ligand charge transfer simultaneously. Importantly, the absorption spectra and emission maxima can be tuned significantly by changing the N^?N ligands and C^?N ligands. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012     

Decreased Turn‐On Times of Single‐Component Light‐Emitting Electrochemical Cells by Tethering an Ionic Iridium Complex with Imidazolium Moieties

We report a significant decrease in turn‐on times of light‐emitting electrochemical cells (LECs) by tethering imidazolium moieties onto a cationic Ir complex. The introduction of two imidazolium groups at the ends of the two alkyl side chains of [Ir(ppy)₂(dC6‐daf)]⁺(PF₆)^? (ppy=2‐phenylpyridine, dC6‐daf=9,9′‐dihexyl‐4,5‐diazafluorene) gave the complex [Ir(ppy)₂(dC6MIM‐daf)]³⁺[(PF₆)^?]₃ (dC6MIM‐daf=9,9‐bis[6‐(3‐methylimidazolium)hexyl]‐1‐yl‐4,5‐diazafluorene). Both complexes exhibited similar photoluminescent/electrochemical properties and comparable electroluminescent efficiencies. The turn‐on times of the LECs based on the latter complex, however, were much lower than those of devices based on the former. The improvement is ascribed to increased concentrations of mobile counterions ((PF₆)^?) in the neat films and a consequent increase in neat‐film ionic conductivity. These results demonstrate that the technique is useful for molecular modifications of ionic transition‐metal complexes (ITMCs) to improve the turn‐on times of LECs and to realize single‐component ITMC LECs compatible with simple driving schemes.     

IrIII and RuII Complexes Containing Triazole‐Pyridine Ligands: Luminescence Enhancement upon Substitution with β‐Cyclodextrin

Novel 2‐(1‐substituted‐1H‐1,2,3‐triazol‐4‐yl)pyridine (pytl) ligands have been prepared by “click chemistry” and used in the preparation of heteroleptic complexes of Ru and Ir with bipyridine (bpy) and phenylpyridine (ppy) ligands, respectively, resulting in [Ru(bpy)₂(pytl‐R)]Cl₂ and [Ir(ppy)₂(pytl‐R)]Cl (R=methyl, adamantane (ada), β‐cyclodextrin (βCD)). The two diastereoisomers of the Ir complex with the appended β‐cyclodextrin, [Ir(ppy)₂(pytl‐βCD)]Cl, were separated. The [Ru(bpy)₂(pytl‐R)]Cl₂ (R=Me, ada or βCD) complexes have lower lifetimes and quantum yields than other polypyridine complexes. In contrast, the cyclometalated Ir complexes display rather long lifetimes and very high emission quantum yields. The emission quantum yield and lifetime (Φ=0.23, τ=1000 ns) of [Ir(ppy)₂(pytl‐ada)]Cl are surprisingly enhanced in [Ir(ppy)₂(pytl‐βCD)]Cl (Φ=0.54, τ=2800 ns). This behavior is unprecedented for a metal complex and is most likely due to its increased rigidity and protection from water molecules as well as from dioxygen quenching, because of the hydrophobic cavity of the βCD covalently attached to pytl. The emissive excited state is localized on these cyclometalating ligands, as underlined by the shift to the blue (450 nm) upon substitution with two electron‐withdrawing fluorine substituents on the phenyl unit. The significant differences between the quantum yields of the two separate diastereoisomers of [Ir(ppy)₂(pytl‐βCD)]Cl (0.49 vs. 0.70) are attributed to different interactions of the chiral cyclodextrin substituent with the Δ and Λ isomers of the metal complex.     

Synthesis,characterization and optical properties of a new cationic cyclometalated platinum(ii) complex

The cyclometalated platinum (II) complex, [Pt(ppy)(ppyH)₂] OTF, 2 , in which ppy and ppyH denote the cyclometalated and non‐cyclometalated 2‐phenylpyridine ligand respectively, was prepared from the reaction of the platinum(IV) complex [PtMe₃(OTF)], 1 , with 3 equiv 2‐phenylpyridine at room temperature. The cyclometalated complex 2 was characterized using ¹H NMR spectroscopy. The solid state structure of 2 was further identified by single crystal X‐ray structure determination. 2 displays a green emission in solution and in solid state at room temperature and TD‐DFT calculations is used to elucidate the origin of the electronic transitions in the UV–vis spectrum of 2 .     

Long‐Lived Room‐Temperature Deep‐Red‐Emissive Intraligand Triplet Excited State of Naphthalimide in Cyclometalated IrIII Complexes and its Application in Triplet‐Triplet Annihilation‐Based Upconversion

Cyclometalated Ir^III complexes with acetylide ppy and bpy ligands were prepared (ppy=2‐phenylpyridine, bpy=2,2′‐bipyridine) in which naphthal ( Ir‐2 ) and naphthalimide (NI) were attached onto the ppy ( Ir‐3 ) and bpy ligands ( Ir‐4 ) through acetylide bonds. [Ir(ppy)₃] ( Ir‐1 ) was also prepared as a model complex. Room‐temperature phosphorescence was observed for the complexes; both neutral and cationic complexes Ir‐3 and Ir‐4 showed strong absorption in the visible range (ε=39600 M ^?1 cm^?1 at 402 nm and ε=25100 M ^?1 cm^?1 at 404 nm, respectively), long‐lived triplet excited states (τ_T=9.30 μs and 16.45 μs) and room‐temperature red emission (λ_em=640 nm, Φ_p=1.4 % and λ_em=627 nm, Φ_p=0.3 %; cf. Ir‐1 : ε=16600 M ^?1 cm^?1 at 382 nm, τ_em=1.16 μs, Φ_p=72.6 %). Ir‐3 was strongly phosphorescent in non‐polar solvent (i.e., toluene), but the emission was completely quenched in polar solvents (MeCN). Ir‐4 gave an opposite response to the solvent polarity, that is, stronger phosphorescence in polar solvents than in non‐polar solvents. Emission of Ir‐1 and Ir‐2 was not solvent‐polarity‐dependent. The T₁ excited states of Ir‐2 , Ir‐3 , and Ir‐4 were identified as mainly intraligand triplet excited states (³IL) by their small thermally induced Stokes shifts (ΔE_s), nanosecond time‐resolved transient difference absorption spectroscopy, and spin‐density analysis. The complexes were used as triplet photosensitizers for triplet‐triplet annihilation (TTA) upconversion and quantum yields of 7.1 % and 14.4 % were observed for Ir‐2 and Ir‐3 , respectively, whereas the upconversion was negligible for Ir‐1 and Ir‐4 . These results will be useful for designing visible‐light‐harvesting transition‐metal complexes and for their applications as triplet photosensitizers for photocatalysis, photovoltaics, TTA upconversion, etc.     

Charge‐Neutral Amidinate‐Containing Iridium Complexes Capable of Efficient Photocatalytic Water Reduction

Two new charge‐neutral iridium complexes, [Ir(tfm‐ppy)₂(N,N′‐diisopropyl‐benzamidinate)] ( 1 ) and [Ir(tfm‐ppy)₂(N,N′‐diisopropyl‐4‐diethylamino‐3,5‐dimethyl‐benzamidinate)] ( 2 ) (tfm‐ppy=4‐trifluoromethyl‐2‐phenylpyridine) containing an amidinate ligand and two phenylpyridine ligands were designed and characterised. The photophysical properties, electrochemical behaviours and emission quenching properties of these species were investigated. In concert with the cobalt catalyst [Co(bpy)₃]²⁺, members of this new class of iridium complexes enable the photocatalytic generation of hydrogen from mixed aqueous solutions via an oxidative quenching pathway and display long‐term photostability under constant illumination over 72 h; one of these species achieved a relatively high turnover number of 1880 during this time period. In the case of complex 1 , the three‐component homogeneous photocatalytic system proved to be more efficient than a related system containing a charged complex, [Ir(tfm‐ppy)₂(dtb‐bpy)]⁺ ( 3 , dtb‐bpy=4,4′‐di‐tert‐butyl‐2,2′‐dipyridyl). In combination with a rhodium complex as a water reduction catalyst, the performances of the systems using both complexes were also evaluated, and these systems exhibited a more efficient catalytic propensity for water splitting than did the cobalt‐based systems that have been studied previously.     

A Tri‐µ‐O‐S‐O Manganese Dimer: Synthesis,Structral and EPR Study

A Tri‐µ‐O‐S‐O coordinative manganese dimer: [Mn₂(SO₄)₂(phen)₄]·CH₃OH (phen1,10‐phenanthroline) ( 1 ) was yielded by the reaction of 1,10‐phenanthroline and MnSO₄·H₂O in a mixed solvent of methanol and acetonitrile under room temperature and was structurally characterized. Single crystal analysis shows that complex 1 has polymeric structure based on binuclear Mn(II) units bridged by O‐S‐O groups of two SO₄²⁻ anion. The UV spectrum of the complex clarifies that each metal‐organic building unit parallels with each other through the Π‐Π interactions of face‐to‐face separations of two 1,10‐phen planes among the complex, forming a layered structure. And the electronic paramagnetic resonance (EPR) signal clearly indicates that those manganese atoms in complex 1 are in +2 oxidation states.     

Synthesis,Characterization, Antibacterial and Antifungal Activity of Yttrium(III) Complexes Including 1,10‐Phenanthroline

Two rare metal coordination complexes of yttrium(III) including 1,10‐phenanthroline, Y(phen)₂(NO₃)₃ and (phenH)₂[Y₂(pydc)₃(NO₃)₂·6H₂O] (phen=1,10‐phenanthroline, pydc=2,6‐pyridinedicarboxylate), and a proton transfer compound (phenH⁺)₂(pydc^2?) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra (IR), nuclear magnetic resonance (NMR) and thermal analysis. The proposed structures of yttrium complexes were exhibited. The in vitro biological activities of the newly synthesized complexes have also been investigated against Bacillus coli, Staphylococcus aureus and Candida albicans. The results showed that yttrium(III) complexes including 1,10‐phenanthroline exhibited better antibacterial/antifungal activity than their ligands and corresponding compounds.     

Experimental and Theoretical Studies on DNA‐Binding and Spectral Properties of ‘Light Switch’ Complexes [Ru(L)2(ppn)]2+ (L=2,2′‐Bipyridine and 1,10‐Phenanthroline; ppn=Pteridino[6,7‐f] [1,10]phenanthroline‐11,13‐diamine)

The ligand pteridino[6,7‐f] [1,10]phenanthroline‐11,13‐diamine (ppn) and its Ru^II complexes [Ru(bpy)₂(ppn)]²⁺ ( 1 ; bpy=2,2′‐bipyridine) and [Ru(phen)₂(ppn)]²⁺ ( 2 ; phen=1,10‐phenanthroline) were synthesized and characterized by elemental analysis, electrospray MS, ¹H‐NMR, and cyclic voltammetry. The DNA‐binding behaviors of 1 and 2 were studied by spectroscopic and viscosity measurements. The results indicate that both complexes strongly bind to calf‐thymus DNA in an intercalative mode, with DNA‐binding constants K_b of (1.7±0.4)?10⁶ M ^?1 and (2.6±0.2)?10⁶ M ^?1, respectively. The complexes 1 and 2 exhibit excellent DNA‐‘light switch’ performances, i.e., they do not (or extremely weakly) show luminescence in aqueous solution at room temperature but are strongly luminescent in the presence of DNA. In particular, the experimental results suggest that the ancillary ligands bpy and phen not only have a significant effect on the DNA‐binding affinities of 1 and 2 but also have a certain effect on their spectral properties. [Ru(phen)₂(ppn)]²⁺( 2 ) might be developed into a very prospective DNA‐‘light switch’ complex. To explain the DNA‐binding and spectral properties of 1 and 2 , theoretical calculations were also carried out applying the DFT/TDDFT method.     

Crystal Structure of Complex Tris（4,4,4—trifluoro—1—pheny1—1,3—butanedione）（1,10—phenanthroline）Europium（Ⅲ）

The complex Eu(btfa)₃ (phen) (btfa=4,4,4‐trifluoro‐1‐phenyl‐1, 3‐butanedione, phen = 1,10‐phenanthroline) has been prepared and characterized by elemental analysis, IR and UV spectroscopies. The crystal and molecular structures of the complex have been determined by X‐ray diffraction analysis. It belongs to the monoclinic crystal system, space group P2₁/c with a = 0.9700(2) nm, b = 3.7450(5) nm, c = 1.0917(3) nm, β = 92.51(2)°, V = 3.962(1) nm⁵, Z = 4, D_c = 1.639 g/cm³, μ = 1.676 mm^?1, F(000) = 1936, R₁, = 0.0388, wR₂ = 0.0775. Structure analysis shows that the europium(III) ion is coordinated to six oxygen atoms of β‐diketonate anions and two nitrogen atoms of phenanthroline molecule. The coordination polyhedron is an approximate square antiprism.     

Highly Sensitive and Selective Amperometric Detection of Periodate at Glassy Carbon Electrode Modified with a Cyclometalated Iridium(III) Complex and Single‐Wall Carbon Nanotubes

Single‐wall carbon nanotubes (SWCNTs) were used as an immobilization matrix to incorporate [Ir(ppy)₂(phen‐dione)](PF₆) complex onto a glassy carbon electrode for the study of electrocatalytic reduction of periodate ion. Detailed preliminary electrochemical data for the Ir(III)‐complex in acetonitrile solution and for the modified GCE/SWCNTs/[Ir(ppy)₂(phen‐dione)](PF₆)/CGE are presented. The modified electrode was applied to selective amperometric detection of periodate through its electrocatalytic reduction to iodide at 0.200 V and pH 2.0. The use of amperometry resulted in two calibration plots over the concentration ranges of 1‐20 μM and 20‐450 μM, with a detection limit of 0.6 μM and sensitivity of 198 nA μM^?1.     

Electrochemiluminescence Studies of Phosphorescent Dopant and Host Molecules of Polymer Light-emitting Diodes

Electrochemiluminescence (ECL) from tris(2‐phenylpyridine)irdium [Ir(ppy)₃] was investigated following cross reaction of its anion with oxidized poly(N‐vinyl‐carbazole) (PVK) and its cation with reduced 2‐(4‐biphenylyl)‐5‐(4‐tert‐butyl‐phenyl)‐1,3,4‐oxadiazole (PBD). Both cross reactions show Ir(ppy)₃ emission and the cross reaction of PVK^+·/Ir(ppy)⁻₃ showed the highest ECL intensity. The comparisons of the reaction enthalpy and the energy of Ir(ppy)₃ light emitting shows that reaction between PVK^+· and Ir(ppy)⁻₃ is energy sufficient to populate metal‐to‐ligand charge transfer (MLCT) excited singlet (3.04 eV) of Ir(ppy)₃, while the reaction between Ir(ppy)⁺₃ and PBD^{− ·} is energy efficient to populate MLCT excited triplet (2.4 eV). The ECL result in solution reveals that the energy released from charge transfer between the Ir(ppy)₃ and PVK or PBD is sufficient to produce the excited state of Ir(ppy)₃ in solid polymer light‐emitting diodes (PLEDs) based on PVK:PBD hosts doped by Ir(ppy)₃. These results obtained will provide further insight into charge‐transfer excitation in PLEDs.     

Nucleic Acid Biosensor for Detection of Human Immunodeficiency Virus Using Aquabis(1,10‐phenanthroline)copper(II) Perchlorate as Electrochemical Indicator

The electrochemical behavior of aquabis(1,10‐phenanthroline)copper(II) perchlorate [Cu(H₂O)(phen)₂]·2ClO₄, where phen=1,10‐phenanthroline, on binding to DNA at a glassy carbon electrode (GCE) and in solution, was described. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) results showed that [Cu(H₂O)(phen)₂]²⁺ had excellent electrochemical activity on the GCE with a couple of quasi‐reversible redox peaks. The interaction mode between [Cu(H₂O)(phen)₂]²⁺ and double‐strand DNA (dsDNA) was identified to be intercalative binding. An electrochemical DNA biosensor was developed with covalent immobilization of human immunodeficiency virus (HIV) probe for single‐strand DNA (ssDNA) on the modified GCE. Numerous factors affecting the probe immobilization, target hybridization, and indicator binding reactions were optimized to maximize the sensitivity and speed of the assay. With this approach, a sequence of the HIV could be quantified over the range from 7.8×10^?9 to 3.1×10^?7 mol·L^?1 with a linear correlation of γ=0.9987 and a detection limit of 1.3×10^?9 mol·L^?1.     

Fabrication of Self‐Assembled Tris(1,10‐phenanthroline) ruthenium/12‐Molybdophosphoric Acid Films with Bifunctional Electrocatalytic and Photoluminescent Properties

The thin films containing transition metal complex tris(1,10‐phenanthroline) ruthenium(II) Ru(phen)₃Cl₂ (abbr Ru(phen)₃, phen=1,10‐phenanthroline), and 12‐molybdophosphoric acid [PMo₁₂O₄₀]_3? (abbr PMo₁₂) were fabricated on quartz, silicon and ITO substrates by layer‐by‐layer (LBL) method. The LBL films were characterized by the UV‐vis spectroscopy, X‐ray photoelectron spectroscopy, atomic force microscopy and cyclic voltammetry. The films can catalyze both the reduction of ClO , BrO , IO , and the oxidation of C₂O due to the presence of bifunctional composite, and the redox potentials depend on pH as a result of protonation. The photoluminescence of films were also investigated. The films exhibited photoluminescence arising from π*–t_2g ligand‐to‐metal transition of Ru(phen)₃.     

Greenish‐yellow‐, yellow‐, and orange‐light‐emitting iridium(III) polypyridyl complexes with poly(ε‐caprolactone)–bipyridine macroligands

A set of novel greenish‐yellow‐, yellow‐, and orange‐light‐emitting polymeric iridium(III) complexes were synthesized with the bridge‐splitting method. The respective dimeric precursor complexes, [Ir(ppy)₂‐μ‐Cl]₂ (ppy = 2‐phenylpyridine) and [Ir(ppy? CHO)₂‐μ‐Cl]₂ [ppy? CHO = 4‐(2‐pyridyl)benzaldehyde], were coordinated to 2,2′‐bipyridine carrying poly(ε‐caprolactone) tails. The resulting emissive polymers were characterized with one‐dimensional (¹H) and two‐dimensional (¹H? ¹H correlation spectroscopy) nuclear magnetic resonance and infrared spectroscopy, gel permeation chromatography, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, and the successful coordination of the iridium(III) centers to the 2,2′‐bipyridine macroligand was revealed. The thermal behavior was studied with differential scanning calorimetry and correlated with atomic force microscopy. Furthermore, the quantitative coordination was verified by both the photophysical and electrochemical properties of the mononuclear iridium(III) compounds. The photoluminescence spectra showed strong emissions at 535 and 570 nm. The color shifts depended on the substituents of the cyclometallating ligands. Cyclic voltammetry gave oxidation potentials of 1.23 V and 1.46 V. Upon the excitation of the films at 365 nm, yellow light was observed, and this could allow potential applications in light‐emitting devices. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2765–2776, 2005     

One‐dimensional copper(II) coordination polymers based on 1,3‐bis(pyridin‐4‐yl)propane and diimine ligands

Two one‐dimensional (1D) coordination polymers (CPs), namely catena‐poly[[[aqua(2,2′‐bipyridine‐κ²N,N′)(nitrato‐κO)copper(II)]‐μ‐1,3‐bis(pyridin‐4‐yl)propane‐κ²N:N′] nitrate], {[Cu(NO₃)(C₁₀H₈N₂)(C₁₃H₁₄N₂)(H₂O)]·NO₃}_n ( 1 ), and catena‐poly[[[aqua(nitrato‐κO)(1,10‐phenanthroline‐κ²N,N′)copper(II)]‐μ‐1,3‐bis(pyridin‐4‐yl)propane‐κ²N:N′] nitrate], {[Cu(NO₃)(C₁₂H₈N₂)(C₁₃H₁₄N₂)(H₂O)]·NO₃}_n ( 2 ), have been synthesized using [Cu(NO₃)(NN)(H₂O)₂]NO₃, where NN = 2,2′‐bipyridine (bpy) or 1,10‐phenanthroline (phen), as a linker in a 1:1 molar ratio. The CPs were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray structure determination. The 1,3‐bis(pyridin‐4‐yl)propane (dpp) ligand acts as a bridging ligand, leading to the formation of a 1D polymer. The octahedral coordination sphere around copper consists of two N atoms from bpy for 1 or phen for 2 , two N atoms from dpp, one O atom from water and one O atom from a coordinated nitrate anion. Each structure contains two crystallographically independent chains in the asymmetric unit and the chains are linked via hydrogen bonds into a three‐dimensional network.     

多吡啶锌配合物键合与切割DNA研究

The complex of Zn[(phen)(dione)Cl]ClO_4·H_2O(where phen is 1,10-phenanthroline and dione is 1,10-phenan-throline-5,6-dione)has been synthesized and characterized.The interaction of the complex with DNA was investi-gated using UV absorption,fluorescence spectroscopy and electrophoresis measurements.The results show that thecomplex mainly binds to the double helix of DNA with intercalation mode and the binding constant K is 2.4×10~4mol~(-1)·L.Moreover,the complex can efficiently cleave plasmid DNA at physiological pH and temperature.Thecleavage occurs via a hydrolysis mechanism,which is showed by adding radical scavengers,rigorously anaerobicexperiments,analysis for malondialdehyde-like products,and the hydrolysis experiment of BDNPP with a rate con-stant k_(obs)of 5.3×10~(-6)s~(-1).