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Phenanthroline Ligand (phenanthroline + ligand)
Selected AbstractsTriplet MLCT Photosensitization of the Ring-Closing Reaction of Diarylethenes by Design and Synthesis of a Photochromic Rhenium(I) Complex of a Diarylethene-Containing 1,10-Phenanthroline LigandCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2006Chi-Chiu Ko Dr. Abstract Synthesis of the diarylethene-containing ligand L1 based on Suzuki cross-coupling reaction between thienyl boronic acid and the dibromophenanthroline ligand is reported. On coordination to the rhenium(I) tricarbonyl complex system, the photochromism of L1 could be photosensitized and consequently extended from intraligand excitation at ,,340 nm in the free ligand to metal-to-ligand charge-transfer (MLCT) excitation at ,,480 nm in the complex. The photochromic reactions were studied by 1H NMR, UV/Vis, and steady-state emission spectroscopy. Photosensitization was further probed by ultrafast transient absorption and time-resolved emission spectroscopy. The results provided direct evidence that the formation of the closed form by the MLCT-sensitized photochromic process was derived from the 3MLCT excited state. This supports the photosensitization mechanism, which involves an intramolecular energy-transfer process from the 3MLCT to the 3IL(L1) state that initiated the ring-closure reaction. The photophysical and electrochemical properties of the complex were also investigated. [source] Synthesis and Photophysical Properties of Copper(I) Complexes Obtained from 1,10-Phenanthroline Ligands with Increasingly Bulky 2,9-SubstituentsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2010Gianluca Accorsi Abstract In this paper, we describe the synthesis and the electronic properties of a series of [Cu(NN)2]+ systems. The NN ligands investigated are 2,9-bis[(tert -butyldimethylsilyloxy)methyl]-1,10-phenanthroline (1), 2,9-bis[(triisopropylsilyloxy)methyl]-1,10-phenanthroline (2), 2,9-bis[(tert -butyldiphenylsilylmoxy)ethyl]-1,10-phenanthroline (3), 2,9-bis[2,6-bis(benzyloxy)phenethyl]-1,10-phenanthroline (4) and 2-(1,3-diphenylpropan-2-yl)-9-phenethyl-1,10-phenanthroline (5). The electrochemical properties and the ground state electronic absorption spectra of Cu(1)2,Cu(5)2 are in line with the classical behaviour of such [Cu(NN)2]+ derivatives. Whereas all the compounds exhibit MLCT luminescence centered around 630,650 nm, the emission quantum yields and the lifetimes are dramatically different as a function of stereoelectronic effects and/or the possibility of internal exciplex quenching when oxygen-containing functional groups are attached to the phenanthroline ligands. [source] Phenanthroline Ligands in Aryl Palladium Hydrazinato Complexes: Catalysts for Efficient Coupling of Azo Compounds with Aryl Boronic Acids.CHEMINFORM, Issue 50 2007Kilian Muniz Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] One-Dimensional Network Constructed by Salicylate and Phenanthroline Ligands with Copper (II)CHINESE JOURNAL OF CHEMISTRY, Issue 10 2002Lag-Guan Zhu Abstract A novel complex, [Cu2 (phen) (sal) (Hsal)2]n (1), was synthesized and structurally characterized. The base dimeric units are hold by sal ligands and extended into 1-D network. The carboxylate groups of salicylates coordinate to the central ion in three different coordination modes: chelating, bridging and bridging-chelating. In the case of bridging-chelating of the carboxylate group of the salicylate, all three oxygen atoms of salicylate are bidentately coordinated to copper ion, namely, ,4 -,3 binding mode. [source] Charge-density analysis of the ground state of a photochromic 1,10-phenanthroline zinc(II) bis(thiolate) complexACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2010Stephan Scheins The charge density of the title compound was determined at 90,K, using a spherical crystal of 150,µm diameter. The proper treatment of the Zn atom in the pseudo-tetrahedral environment is considered in detail. A satisfactory refinement is only obtained when anharmonic Gram,Charlier parameters are included as variables in the refinement. A successful combined anharmonic/multipole refinement indicates a small polarization of the 4s shell in the anisotropic environment. One of the two toluenethiols is approximately ,-stacked with the phenanthroline ligand. A bond path is found connecting the two ligands. In addition the Zn,S bond to this ligand is slightly extended compared with the same bond to the second toluenethiol. A separate photocrystallographic and theoretical study indicates the long wavelength emission of the title compound to be due to a ligand-to-ligand charge transfer (LLCT) from a toluenethiol to the phenanthroline ligand. The charge-density results do not provide a basis for deciding which of the thiole ligands is the source of the transferred electron density. This result is in agreement with the theoretical calculations, which show comparable oscillator strengths for charge transfer from either of the ligands. [source] (N -{[4-(1,3-Benzothiazol-2-yl)anilino]carbonylmethyl-,O}iminodiacetato-,3O,N,O,)(1,10-phenanthroline-,2N,N,)cobalt(II) pentahydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2008Guo-Wu Lin The title compound, [Co(C19H15N3O5S)(C12H8N2)]·5H2O, has a moderately distorted octahedral coordination environment composed of two N atoms of a 1,10-phenanthroline ligand and one N and three O atoms of an N -{[4-(1,3-benzothiazol-2-yl)anilino]carbonylmethyl}iminodiacetate (ZL-52,) ligand. The ring systems of the phenanthroline and ZL-52, ligands are coplanar and the complexes pack in layers parallel to the ab plane with the rings of adjacent complexes facing one another. The layers stack along the c axis and are linked by hydrogen bonds involving the five water solvent molecules in the asymmetric unit and O atoms of the acetate groups of the ZL-52, ligand. This is believed to be the first crystal structure of a complex of a 2-(4-aminophenyl)benzothiazole ligand. [source] Comparative Study of Copper- and Silver-Catalyzed Protodecarboxylations of Carboxylic AcidsCHEMCATCHEM, Issue 4 2010Lukas Abstract The protodecarboxylation of aromatic carboxylic acids by various copper and silver catalysts is investigated with the help of density functional calculations and experimental studies. The computational results reveal that the catalytic activity of copper(I),1,10-phenanthroline catalysts increases with the introduction of electron-rich substituents at the phenanthroline ligand. They also predicted that for some substrates, silver complexes should possess a substantially higher decarboxylating activity than copper, which is confirmed by experimental studies, leading to the discovery of a silver(I) catalyst that effectively promotes the protodecarboxylation of various carboxylic acids at temperatures in the range of 80,120,°C,more than 50,°C below those of the best known copper(I) catalyst. The scope of the new system complements that of the copper(I)-based method as it includes benzoates for example, with halogen or ether groups in the ortho positions. [source] Influence of the Protonic State of an Imidazole-Containing Ligand on the Electrochemical and Photophysical Properties of a Ruthenium(II),Polypyridine-Type ComplexCHEMISTRY - A EUROPEAN JOURNAL, Issue 29 2007Annamaria Quaranta Dr. Abstract The synthesis and characterisation of [Ru(bpy)2(PhenImHPh)]2+ where PhenImHPh represents the 2-(3,5-di- tert -butylphenyl)imidazo[4,5- f][1,10]phenanthroline ligand are described. The compounds issued from the three different protonic states of the imidazole ring [Ru(bpy)2(PhenImPh)]+ (I), [Ru(bpy)2(PhenImHPh)]2+ (II) and [Ru(bpy)2(PhenImH2Ph)]3+ (III) were isolated and spectroscopically characterised. The X-ray structures of [Ru(bpy)2(PhenImPh)](PF6),H2O,6,MeOH, [Ru(bpy)2(PhenImHPh)](NO3)2,H2O,3,MeOH and [Ru(bpy)2(PhenImH2Ph)](PF6)3, 5,H2O are reported. Electrochemical data obtained on these complexes indicate almost no potential shift for the RuIII/II redox couple. Therefore a Coulombic effect between the imidazole ring and the metal centre can be ruled out. The monooxidised forms of I and II have been characterised by EPR spectroscopy and are reminiscent of the presence of a radical species. The emission properties of the parent compound [Ru(bpy)2(PhenImHPh)]2+ were studied as a function of pH and both the lifetimes and intensities decreased upon deprotonation. Photophysical properties, investigated in the absence and presence of an electron acceptor (methylviologen), were distinctly different for the three compounds. Transient absorption features indicate that unique excited states are involved. Theoretical data obtained from DFT calculations in water on the three protonic forms are presented and discussed in the light of the experimental results. [source] Synthesis and Photophysical Properties of Copper(I) Complexes Obtained from 1,10-Phenanthroline Ligands with Increasingly Bulky 2,9-SubstituentsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2010Gianluca Accorsi Abstract In this paper, we describe the synthesis and the electronic properties of a series of [Cu(NN)2]+ systems. The NN ligands investigated are 2,9-bis[(tert -butyldimethylsilyloxy)methyl]-1,10-phenanthroline (1), 2,9-bis[(triisopropylsilyloxy)methyl]-1,10-phenanthroline (2), 2,9-bis[(tert -butyldiphenylsilylmoxy)ethyl]-1,10-phenanthroline (3), 2,9-bis[2,6-bis(benzyloxy)phenethyl]-1,10-phenanthroline (4) and 2-(1,3-diphenylpropan-2-yl)-9-phenethyl-1,10-phenanthroline (5). The electrochemical properties and the ground state electronic absorption spectra of Cu(1)2,Cu(5)2 are in line with the classical behaviour of such [Cu(NN)2]+ derivatives. Whereas all the compounds exhibit MLCT luminescence centered around 630,650 nm, the emission quantum yields and the lifetimes are dramatically different as a function of stereoelectronic effects and/or the possibility of internal exciplex quenching when oxygen-containing functional groups are attached to the phenanthroline ligands. [source] Ionic Iridium(III) Complexes with Bulky Side Groups for Use in Light Emitting Cells: Reduction of Concentration QuenchingADVANCED FUNCTIONAL MATERIALS, Issue 13 2009Carsten Rothe Abstract Here, the photophysics and performance of single-layer light emitting cells (LECs) based on a series of ionic cyclometalated Ir(III) complexes of formulae and where ppy, bpy, and phen are 2-phenylpyridine, substituted bipyridine and substituted phenanthroline ligands, respectively, are reported. Substitution at the N,N ligand has little effect on the emitting metal-ligand to ligand charge-transfer (MLLCT) states and functionalization at this site of the complex leads to only modest changes in emission color. For the more bulky complexes the increase in intermolecular separation leads to reduced exciton migration, which in turn, by suppressing concentration quenching, significantly increases the lifetime of the excited state. On the other hand, the larger intermolecular separation induced by bulky ligands reduces the charge carrier mobility of the materials, which means that higher bias fields are needed to drive the diodes. A brightness of ca. 1000,cd,m,2 at 3,V is obtained for complex 5, which demonstrates a beneficial effect of bulky substituents. [source] | ||||||||||||||||||||||