Synthesis and Luminescence Property of 4,4＇-Bis（2,2-di（4-fluorophenyl）vinyl）biphenyl for Organic Blue-Light-Emitting Diodes

The novel fluorinated distyrylarylene, 4,4＇-bis（2,2-di（4-fluorophenyl）vinyl）biphenyl （DFPVBi）, was synthesized and fully characterized. The structure was confirmed with IR, 1↑H NMR, 13↑C NMR, 19↑F NMR and MS analyses. Its electronic and photoluminescence properties were investigated by UV-Vis absorption, cyclic voltammetry and fluorescence spectroscopy. The energy levels of the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO） are --5.77 and --2.75 eV, respectively. The electroluminescence proper- ties of the organic light-emitting diode fabricated by DFPVBi were also studied. The device exhibits a pure blue emission peaked at 454 nm, which indicates a maximum luminance of 5872 cd/m ^2 at 14.2 V and a maximum current efficiency of 2.82 cd/A at 10V, respectively.     

New Copper（Ⅱ） and Nickel（Ⅱ） Complexes of 4-Morpholinoacetophenone Thiosemicarbazone： Structural, Electrochemical and Antimicrobial Studies

4-Morpholinoacetophenone thiosemicarbazone, MAPT, and its nickel（Ⅱ） and copper（Ⅱ） complexes have been prepared and characterized by elemental analysis, magnetic susceptibility, spectral methods （FT-IR, ^1H NMR） and cyclic voltammetry. Electrochemical behaviors of the complexes have been studied by cyclic voltammetry in DMF media showing metal centered reduction processes for both of them. The redox properties, nature of the electrode processes and the stability of the complexes were discussed. [Cu（MAPT）2]Cl2 complex shows Cu（Ⅱ）/Cu（Ⅰ） couple and quasi-reversible wave associated with the Cu（Ⅲ）/Cu（Ⅱ） process. The reduction/oxidation potential values depend on the structures of complexes. Also, the antimicrobial activities of these complexes were determined against S. aureus, E. coli and B. subtilis.     

四种钌（Ⅱ）配合物的中心离子电化学行为的比较

The electrochemical behavior of mononuclear and symmetrical binuclear ruthenium（Ⅱ） complexes [Ru1:Ru(bpy)2DIPB(ClO4)2,Ru2:(bpy)2 Ru(DIPB)Ru(bpy)2(ClO4)4,Ru3:Ru(phen)2DIPB(ClO4)2 and Ru4:(phen)2 Ru(DIPB)Ru (phen)2(ClO4)4] containing binuclear ligand 2,2′-bipyridine(bpy),1,10-phenanthroline(phen) and bridging ligand 1,4-di-[2-imidazo[4,5-f][1,10] phenanthroine benzene(DIPB) on a platinum electrode and the intermetallic interaction of binuclear complexes have been investigated using cyclic voltammetry,cyclic ac voltammetry and differential capacitance techniques,etc.In acetonitrile solution with a concentration of 0.1 mol穌m-3 TBAP,the central ions in four complexes all display single 1e and 2e reversible oxidation- reduction waves on the cyclic voltammograms,with apparent diffusion coefficients of the mononuclear complexed cations being larger than that of the binuclear ones.The apparent diffusion coefficients for complexed cations with auxiliary ligands bpy are also found to be larger than that with ligands phen.It appears that the overlapping of two continuous single-electron processes by cyclic ac voltammetry and differential capacitance techniques occurs during the redox processes of the central ions binuclear complexes.The results show that a weak electronic interaction exits between the two central ruthenium ions in binuclear complexes.     

Synthesis of N,N,N-4,4＂-Di-（4-methylphenyl）-2,2＇：6＇,2＂- terpyridine-N,N,N-tris（isothiocyanato） Ruthenium（Ⅱ） and Application to Colorimetric Hg^2＋ Sensor

A terpyridine derivative DPTP [di-（4-methylphenyl）-2,2＇：6＇,2＂-terpyridine] was conveniently synthesized from 2-bromopyridine via halogen-dance reaction, Kharash coupling and Stille coupling reaction. Then its corresponding ruthenium complex Ru-DPTP [N,N,N-4,4＇＇-di-（4-methy,phenyl）-2,2＇：6＇,2＂-terpyridine-N,N,N-tris（is,-thi,cyanat,）- ruthenium（H） ammonium] was obtained and fully characterized by IR, UV-Vis, ESI MS and elemental analysis. The MLCT absorption band of Ru-DPTP was blue-shifted from 570 to 500 nm upon addition of Hg^2＋. Among a series of surveyed metal ions, the complex showed a unique recognition to Hg^2＋, indicating that it can be used as a selective colorimetric sensor for Hg^2＋.     

Tris（2,2＇-bipyridyl） Ruthenium（Ⅱ） Doped Silica Film Modified Indium Tin Oxide Electrode and Its Electrochemiluminescent Properties

An approach was reported to synthesize silica hybridized ruthenium bipyridyl complex through amidation reaction by covalent attachment of bis（bipyridyl）-4,4＇-dicarboxy-2,2＇-bipyridyl-ruthenium to （3-aminopropyl）-triethoxysilane. The hybrid complex then was gelatinized through acid catalytic hydrolysis method and a sol-gel modified indium tin oxide electrode was prepared via spin coating technique. As prepared indium tin oxide electrode possesses good stability therein with excellent electrochemiluminescence behavior.     

Syntheses,Characterization,and Crystal Structures of Three New Divalent Metal Sulfonates

Reactions of M（Ⅱ） acetate （M = Cu, Ni） with disodium 4,4＇-biphenyldisulfonate （BPDS） and 2,2＇-bipyridine （2,2＇-bipy） yielded three new metal sulfonates formulated as {[Cu2（2,2＇-bipy）2（H2O）（C2O4）（BPDS）]·2H2O}n 1, [Cu（2,2＇-Bipy）（H2O）3]（BPDS）＇2H2O 2 and [Ni（2,2＇-Bipy）（H2O）4]（BPDS）·2.5H2O 3. These three compounds were characterized by elemental analyses, FT-IR spectra, TG-DTA analyses and single-crystal X-ray diffraction analyses. Compound 1 belongs to the monoclinic system, space group P21/c with a = 17.7942（2）, b = 10.1369（10）, c = 19.8681（3） A, β = 104.323（10）°, V = 3472.20（7）A3, Mr = 893.82, Z = 4, F（000） = 1824,μ（CuKa） = 3.295 mm-1, R = 0.0427 and wR = 0.1278. Compound 2 is of orthorhombic system, space group Pca21 with a = 20.1016（7）, b = 7.2460（2）, c = 17.4802（6）A, V= 2546.10（14）A3, Mr = 622.11, Z= 4, F（000） = 1284,μ （CuKα） = 3.314 mm-1, R = 0.0415 and wR = 0.1291. Compound 3 belongs to the monoclinic system, space group C2/c with a = 15.9204（5）, b = 11.7511（4）, c = 15.2559（4）A, β = 98.886（3）°, V = 2819.85（15）A3, Mr = 1288.60, Z = 2, F（000） = 1340,μ（CuKa） = 2.957 mm^-1, R = 0.0515 and wR = 0.1454. Compound 1 is composed of one-dimensional helical chains of [Cu2（2,2＇-bipy）2（H2O）（C2O4）]2＋ fragments bridged alternately by 4,4＇-biphenyldisulfonate ligands, along the c axis of the unit cell. In compound 2, 4,4＇-biphenyldisulfonate anions are arranged in a zigzag mode and interact with the lattice waters via hydrogen bonds resulting in the formation of infinite chains. Adjacent chains are linked by lattice waters to form 2D extended sheets. The complex cations are located in the interlayer regions and interact with the sheets through hydrogen bonds. In compound 3, the Ni center resides at a crystallographic inversion center and adopts a distorted octahedral coordination sphere. The complex cations interact with 4,4＇-biphenyldisulfonate     

Hybrid Tungstocuprate [ Cu（2,2＇-bpy）3]2 H4 [ CuW12O40 ]· 6H2O Based on Keggin Polyoxoanion [CuW12O40]^6- with Cu^Ⅱ as Heteroatom

A novel hybrid tungstocuprate （ Ⅱ ） [ Cu （2,2＇-bpy） 3 ] 2 H4 [ CuW12O40 ] · 6H2O （ 2,2＇-bpy = 2,2＇-bipyfidine） was synthesized via hydrothermal method and characterized using elemental analyses, IR, UV, XPS, TG-DSC, EPR, and X-ray single crystal diffraction. The structural analysis shows that the complex consists of an unusual Keggin-type polyoxoanion [ CuW12O40 ]^6- and a pair of chiral complex cations [ Cu（2,2＇-bpy） 3 ]^＋ together with four protons and six crystallization water molecules, and the Keggin polyoxoanion is connected with [ Cu （2,2＇-bpy）3 ]^＋v/a multiple C-H…O hydrogen bonds resulting in a dimer.     

Synthesis of New Ruthenium（Ⅱ）Bipyridyl Complexes and Studies on Their Photophysical and Photoelectrochemical Properties

Two new mixed-ligand ruthenium(Ⅱ） complexes,Ru(dcbpy)-(LL)NCS)2[where dcbpy=4,4‘-dicarboxyl-2,2‘‘-bipyridine,LL=4,4‘-bis(N-methyl-anilinomethyl)-2,2‘‘-bipyridine(2)],were synthesized,and the tphotophysical properties of these complexes were studied.The metal-to-ligand charge transfer (MLCT) transitions of these complexes exhibited solvatochromic effect due to the existence of NCS ligands.The MLCT energies also strongly depend on the pH values of the solutions because of protonation and deprotonation of the carboxyl groups.The pKa values of the ground state,4.0 for 1 and 3.8 for 2,were obtained from the titration curves.The photoelectrochemical properties of 1 and 2 as sensitizers in sandwich-type solar cells have been studied.Complex 1 exhibited better photoelectrochemical behavior than complex 2 as expected.It was proved that the design of mixed-ligand complex by introducing electron donating group in one of the ligands should be a promising approach.     

Structure and Photosynthetic Mimicking of Bis（2,6—bis（benzimidazol—2—yl）pyridine）manganese（Ⅱ）

Mn(bzimpy)2(1)[bzimpy=2,6-bis(benzimidazol-2-yl)pyridine],a mononuclear manganese(Ⅱ）complex,was synthesized by the reaction of Mn(OOCMe)2 with bzimpy in absolute ethanol.The complex was structurally characterized by elemental analysis,cyclic voltammetry,and X-ray crystallography.In the complex,the manganese-nitrogen distances were different,and the geometry and the metal ion environment showed the distortion.The cyclic voltammetric measurements have been performed to assess its redox characteristics.The presence of oxidation wave at 0.62V and 0.081V vs.SCE or 0.8V and 1.0v vs.NHE suggested that this complex could catalyze the oxidation of water,therefore,simulate the water-oxidizing complex(WOC) of photosystem Ⅱ (PS Ⅱ).The measurements of photoreduction of 2,6-dichlorophenolindophenol (DCPIP),and oxygen evolution in the manganess-depleted and the comples 1-reconstituted PS Ⅱ preparations just support our conjecture.     

DNA-binding Studies of Daunorubicin in the Presence of Methylene Blue by Spectroscopy and Voltammetry Techniques

The interaction of daunorubicin with calf thymus DNA has been investigated with the use of methylene blue dye as a spectral probe by the application of UV-Vis spectrophotometry, spectrofluorometry and voltammetry. The voltammetric behavior of daunorubicin has been investigated at a glassy carbon electrode using cyclic and differential pulse voltammetry. Both UV-vis spectrophotometry and cyclic voltammetry studies confirmed the intercalation reaction. The results showed that both daunorubicin and methylene blue molecules could intercalate into the double helix of DNA. The apparent binding constant of daunorubicin with DNA has been found to be 7.8 ×104 L•mol－1. The fluorescence signal of daunorubicin and methylene blue was quenched with DNA addition. The Stern-Volmer equation was plotted based on the quenching fluorescence signal of daunorubicin.     

Heteroleptic ruthenium sensitizers that contain an ancillary bipyridine ligand tethered with hydrocarbon chains for efficient dye-sensitized solar cells

New heteroleptic ruthenium complexes have been synthesized and used as the sensitizers for dye‐sensitized solar cells (DSSCs). The ancillary bipyridine ligand contains rigid aromatic segments (fluorene‐, carbazole‐, or dithieno[3,2‐b:2′,3′‐d]pyrrole‐substituted bipyridine) tethered with a hydrophobic hexyl substituent. The conjugated aromatic segment results in significant bathochromic shift and hyperchromic effects in these complexes compared with Z907 (cis‐[Ru LL′ (NCS)₂]; L =4,4′‐dicarboxylic acid‐2,2′‐bipyridine, L′ =4,4′‐dinonyl‐2,2′‐ bipyridine). The long hydrocarbon chains help to suppress the dark current if appropriately disposed. DSSCs that use these complexes exhibit very impressive conversion efficiencies (5.94 to 6.91 %) that surpass that of Z907 ‐based (6.36 %) DSSCs and are comparable with that of N719 ‐based standard cells (7.13 %; N719 =cis‐di(thiocyanato)bis(2,2′‐bipyridyl‐4,4′‐dicarboxylato)ruthenium(II) bis(tetrabutylammonium)) fabricated and measured under similar conditions (active area: 0.5×0.5 cm²; AM 1.5 sunlight).     

A New Luminescent Ruthenium(II) Polypyridine‐derived Dipicolylamine Complex as a Sensor for Cu2+ Ions

A chemo‐sensor [Ru(bpy)₂(bpy‐DPF)](PF₆)₂ ( 1 ) (bpy=2,2′‐bipyridine, bpy‐DPF=2,2′‐bipyridyl‐4,4′‐bis(N,N‐di(2‐picolyl))formylamide) for Cu²⁺ using di(2‐picolyl)amine (DPA) as the recognition group and a ruthenium(II) complex as the reporting group was synthesized and characterized successfully. It demonstrates a high selectivity and efficient signaling behavior only for Cu²⁺ with obvious red‐shifted MLCT (metal‐to‐ligand charge transfer transitions) absorptions and dramatic fluorescence quenching compared with Zn²⁺ and other metal ions.     

Synthesis of Amphiphilic RuII Heteroleptic Complexes Based on Benzo[1,2‐b:4,5‐b′]dithiophene: Relevance of the Half‐Sandwich Complex Intermediate and Solvent Compatibility

The detailed synthesis and characterization of four ruthenium(II) complexes [RuLL′(NCS)₂] is reported, in which L represents a 2,2′‐bipyridine ligand functionalized at the 4,4′ positions with benzo[1,2‐b:4,5‐b′]dithiophene derivatives (BDT) and L′ is 2,2′‐bipyridine‐4,4′‐dicarboxylic acid unit (dcbpy) (NCS=isothiocyanate). The reaction conditions were adapted and optimized for the preparation of these amphiphilic complexes with a strong lipophilic character. The photovoltaic performances of these complexes were tested in TiO₂ dye‐sensitized solar cell (DSSC) achieving efficiencies in the range of 3–4.5 % under simulated one sun illumination (AM1.5G).     

Photophysics of a Ruthenium 4H‐Imidazole Panchromatic Dye in Interaction with Titanium Dioxide

The photophysics of bis(4,4′‐di‐tert‐butyl‐2,2′‐bipyridine‐κ²N,N′)[2‐(4‐carboxyphenyl)‐4,5‐bis(p‐tolylimino‐κN)imidazolato]ruthenium(II) hexafluorophosphate is investigated, both in solution and attached to a nanocrystalline TiO₂ film. The studied substitution pattern of the 4H‐imidazole ligand is observed to block a photoinduced structural reorganization pathway within the 4H‐imidazole ligand that has been previously investigated. Protonation at the 4H‐imidazole ring decreases the excited‐state lifetime in solution. When the unprotonated dye is anchored to TiO₂, photoinduced electron injection occurs from thermally nonrelaxed triplet metal‐to‐ligand charge transfer (³MLCT) states with a characteristic time constant of 0.5 ps and an injection efficiency of roughly 25 %. Electron injection from the subsequently populated thermalized ³MLCT state of the dye does not take place. The energy of this state seems to be lower than the conduction band edge of TiO₂.     

A new 1H-pyridin-(2E)-ylidene ruthenium complex as sensitizer for a dye-sensitized solar cell

The new heteroleptic ruthenium(II) complex containing a 1H-pyridin-(2E)-ylidene (PYE) ligand was synthesized and characterized using UV/Vis, FTIR, and NMR spectroscopies, mass spectrometry, elemental analysis, and cyclic voltammetry. The photovoltaic performance of the ruthenium complex as a charge transfer photosensitizer in nc-titanium dioxide based dye-sensitized solar cell was studied and compared with cis-bis(isothiocyanato)(2,2′-bipyridyl-4,4′-dicarboxylato)(2,2′-bipyridyl-4,4′-di-nonyl)ruthenium(II) (Z907) under standard AM 1.5 sunlight. The complex CS90 gave a photocurrent density of 1.80?mA?cm^?2, 400?mV open-circuit potential, and 0.58 fill factor yielding an efficiency of 0.42% where the reference Z907 yielded an efficiency of 4.12%. The decrease in conversion efficiency observed for CS90 is attributed to a steric interaction between PYE and the TiO₂ surface that prevents optimum binding and also restricts ligand dynamics that are associated with oxidation state changes.     

Role of electronic structure of ruthenium polypyridyl dyes in the photoconversion efficiency of dye‐sensitized solar cells: Semiempirical investigation

ZINDO/S calculations on cis‐Ru(4,4′‐dicarboxy‐2,2′‐bipyridine)₂(X)₂ and cis‐Ru(5,5′‐dicarboxy‐2,2′‐bipyridine)₂(X)₂ complexes where X = Cl^?, CN^?, and NCS^? reveal that the highest occupied molecular orbital (HOMO) of these complexes has a large amplitude on both the nonchromophoric ligand X and the central ruthenium atom. The lowest‐energy metal to ligand charge transfer (MLCT) transition in these complexes involves electron transfer from ruthenium as well as the halide/pseudohalide ligand to the polypyridyl ligand. The contribution of the halide/pseudohalide ligand(X) to the HOMO affects the total amount of charge transferred to the polypyridyl ligand and hence the photoconversion efficiency. The virtual orbitals involved in the second MLCT transition in 4,4′‐dicarboxy‐2,2′‐bipyridine complexes have higher electron density on the ? COOH group compared to the lowest unoccupied molecular orbital and hence a stronger electronic coupling with the TiO₂ surface and higher injection efficiency at shorter wavelengths. In comparison, the virtual orbitals involved in the second MLCT transition in 5,5′‐dicarboxy‐2,2′‐bipyridine complexes have lesser electron density on the ? COOH group, leading to a weaker electronic coupling with the TiO₂ surface and therefore lower efficiency for electron injection at shorter wavelengths for these complexes. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002     

Novel Roles of Metal Ions in Layered Self-assembled Films of Polynuclear Complexes on Their Photoinduced Electron Transfer Properties

Three metal ion bridged self-assembled(SA)films of cis-di(thiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium were fabricated and characterized by contact angle,UV spectra,cyclic voltammetry and XPS.Theirphotoinduced electron transfer properties(PETP)were examined.Among the titled systems,the highest steady an-odic photocurrent of 1773—1843 nA/cm~1 and the highest quantum yield of 3.2% were achieved.The effects of in-cident light intensity,bias voltage,and electron donor were also studied.The possible mechanism of electron trans-fer was proposed.The results reveal that different metal ion in SA films could affect significantly the photoinducedelectron transfer property.Our experimental results clearly show that bridging metal ions can play both functionaland structural roles in these self-assembled systems.This method of forming functional films can provide a new ap-proach to regulate the property of similar systems.     

Solid‐State Electrochemistry and Electrochemiluminescence of Porous Thin Film of [(2,2′‐Bipyridyl)(4‐(2‐pyrrol‐1‐ylethyl)‐4′‐methyl‐2,2′‐bipyridyl)2]ruthenium(II) Monomer Precipitation

A novel fluorescent porous thin film based on the precipitation of the [(2,2′‐bipyridyl)(4‐(2‐pyrrol‐1‐ylethyl)‐4′‐methyl‐2,2′‐bipyridyl)₂]ruthenium(II) (BF₄)₂ complex (pyr‐Ru) was fabricated by easily spreading 2 µL of pyr‐Ru (1 mM in acetonitrile solution) onto the surface of a platinum electrode and drying it in ambient conditions. The morphology of the resulting pyr‐Ru thin film was characterized by scanning electron microscopy (SEM) and fluorescence microscopy. The coating exhibits fluorescent properties of the ruthenium complex and a porous structure with pore diameters of micrometers. The solid‐state electrochemistry and electrochemiluminescence behaviors of the porous pyr‐Ru thin film were investigated in aqueous solution by cyclic voltammetry and step potential.     

Chiral Bis(oxazoline) Ruthenium Complexes with Bipyridyl‐Type N‐Heteroaromatics: Comparative Stereochemical and Photochemical Characterization of their Λ‐ and Δ‐Diastereomeric Geminate Isomers

Diastereomeric geminate pairs of chiral bis(2‐oxazoline) ruthenium complexes with bipyridyl‐type N‐heteroaromatics, Λ‐ and Δ‐[Ru(L‐ L)₂(iPr‐biox)]²⁺ (iPr‐biox=(4S,4′S)‐4,4′‐diisopropyl‐2,2′‐bis(2‐oxazoline); L‐ L=2,2′‐bipyridyl (bpy) for 1 Λ and 1 Δ, 4,4′‐dimethyl‐2,2′‐bipyridyl (dmbpy) for 2 Λ and 2 Δ, and 1,10‐phenanthroline (phen) for 3 Λ and 3 Δ), were separated as BF₄ and PF₆ salts and were subjected to the comparative studies of their stereochemical and photochemical characterization. DFT calculations of 1 Λ and 1 Δ electronic configurations for the lowest triplet excited state revealed that their MO‐149 (HOMO) and MO‐150 (lower SOMO) characters are interchanged between them and that the phosphorescence‐emissive states are an admixture of a Ru‐to‐biox charge‐transfer state and an intraligand excited state within the iPr‐biox. Furthermore, photoluminescence properties of the two Λ,Δ‐diastereomeric series are discussed with reference to [Ru(bpy)₃]²⁺.