共查询到20条相似文献,搜索用时 15 毫秒
1.
Several new dinitritochromium(III) complexes of the type trans-[Cr(L)(ONO)(2)]BF(4), where L is a derivative of the macrocyclic ligand cyclam having pendant aromatic chromophores attached (L = 5,7-dimethyl-6-(substituted)-1,4,8,11-tetraazacyclotetradecane), have been prepared and characterized. Photoexcitation of aqueous solutions containing these complexes at wavelengths corresponding to the pendant chromophore absorption bands led to the generation of NO as detected by an electrochemical sensor. Photophysical data show that the expected fluorescence of the pendant chromophores is largely quenched when the macrocyclic ligand is coordinated to these Cr(III) centers, and this is interpreted in terms of fast energy transfer processes from the ligand-centered pipi states to the Cr(III)-centered ligand field states leading to subsequent cleavage of the Cr(III)-coordinated nitrito ligand. Thus, the chromophores tethered to the coordinated cyclam serve as light-gathering antennae for the intramolecular sensitization of the NO-generating photoreactions at the metal center. 相似文献
2.
Several new chromium(III) complexes have been synthesized utilizing derivatives of the macrocyclic ligand cyclam (1,4,8,11-tetraazacyclotetradecane) with various N-substituted chromophores in the 1 and 8 positions (1,8-R(2)cyclam) where R = CH(3), CH(2)Ph, CH(2)Nph (Nph = naphthyl), and CH(2)Anth (Anth = anthracyl). X-ray crystal structures were determined for all four complexes, and these are formed exclusively in the cis configuration with the two tertiary amines in the "hinge" positions (i.e., along the folding axis) of the coordinated ligand. As a result, the cis isomers appear to be inert to isomerization under conditions dramatically more forcing than needed to effect the cis to trans isomerization of the unsubstituted Cr(cyclam)Cl(2)(+) ion. Photophysical studies demonstrated that emission occurs solely from the metal-centered ligand field doublet excited states regardless of whether initial excitation is into the quartet ligand field bands or into the pi-pi bands of the pendant chromophore. Thus, excitation of the pendant chromophore results in efficient intramolecular energy transfer to the metal centered ligand field excited states. 相似文献
3.
Trans-[Cr(NH3)4(H2O)Cl]Cl2 (A) crystallizes in the monoclinic space group P21/m (No. 11) with a = 6.556(1), b = 10.630(5), c = 6.729(2) Å and β = 96.15(3)°. Trans-[Cr(NH3)4Cl2]I (B) has monoclinic C2/m (No. 12) space group and a = 9.877(2), b = 8.497(2), c = 6.047(2) Å and β = 108.98(2)°. Both unit cells contain two formula units. Cr? Cl, Cr? O(H2O) and three independent Cr? N(NH3) distances for A are 2.98(1), 2.023(2), 2.067(2), 2.086(3) and 2.064(3) °. Cr? Cl and Cr? N(NH3) bonds in B are 2.325(1) and 2.071(2) °. All octahedral angles are close to 90 and 180°. Both structures were refined to very low R values. Water molecule from trans-[Cr(NH3)4(H2O)Cl]2+ is hydrogen bonded to both ionic chlorides. Cation and two anions form the motive which repeats itself in the crystal. Cations and anions of the second structure are distributed in layers. Each cation and anion have coordination number eight. 相似文献
4.
5.
Complexes [MX2(1)] (M = Ni, Pd and Pt; X=Cl and NCS; 1 = 2,11-bis(dialkyl-[or diaryl]phosphinomethyl)benzo[c]phenanthrene; alkyl = cyclohexyl t-butyl; aryl = m-tolyl, p-anisyl and m-CF3 C6H4) have been synthesized. An NMR. study of the t-butyl complexes provides evidence for a “fan-like” motion of the benzo[c]phenanthrene moiety over the plane of the complex. 相似文献
6.
New ionic technetium complexes of the type trans-[Tc(PR3)4Cl2]+ are synthesized by various methods. The simplest method is the reaction of [TcO4]- with the phosphine in methanol in the presence of a chloride salt. Compounds containing PMe2Ph and PMe3 are synthesized and characterized by crystallographic methods. The complexes containing the less bulky phosphine can be prepared from complexes containing the bulker phosphine. The compounds are paramagnetic, with two unpaired electrons. The complexes studied by X-ray diffraction methods are the trans isomers. [Tc(PMe2Ph)4Cl2]PF6 crystallizes in the monoclinic space group P2(1)/c, with a = 11.511(2) A, b = 26.713(7) A, c = 12.688(3) A, beta = 92.79(1) degrees, Z = 4, and R1 = 0.0574. [Tc(PMe3)4Cl2]BPh4 (II) crystallizes in the orthorhombic space group Pbcn, with a = 18.213(5) A, b = 22.950(5) A, c = 19.428(6) A, Z = 8, and R1 = 0.0691. [Tc(PMe3)4Cl2]PF6 crystallizes in the monoclinic space group P2(1)/c, with a = 18.152(7) A, b = 16.838(9) A, c = 18.090(6) A, beta = 106.63(1) degrees, Z = 8, and R1 = 0.0670. The compounds all have octahedral coordination, but an important tetrahedral deformation of the plane containing the Tc and the four P atoms is observed in each case. In II, the two independent Tc atoms are both located on 2-fold axes. 相似文献
7.
To explore the relationships between the structures of ligands and their complexes, we have synthesized and characterized a series of lanthanide complexes with two structurally related ligands, 1,1,1,1-tetrakis{[(2'-(2-benzylaminoformyl))phenoxyl]methyl}methane (L(I)) and 1,1,1,1-tetrakis{[(2'-(2-picolyaminoformyl))phenoxyl]methyl}methane (L(II)). A series of zero- to three-dimensional lanthanide coordination complexes have been obtained by changing the substituents on the Pentaerythritol. Our results revealed that, complexes of the L(I) ligand, {Ln(4)L(I)(3)(NO(3))(12).nC(4)H(10)O}(infinity) (Ln = Nd, Eu, Tb, Er, n = 3 or 6)] show the binodal 3,4-connected three-dimensional interpenetration coordination polymers with topology of a (8(3))(4)(8(6))(3) notation. Compared to L(I), complexes of L(II) present a cage-like homodinuclear [Ln(2)L(II)(2)(NO(3))(6).2H(2)O].nH(2)O (Ln = Nd, Tb, Dy, n = 0 or 1) or a helical one-dimensional coordination {[ErL(II)(NO(3))(3).H(2)O].H(2)O}(infinity) polymer. The luminescence properties of the resulting complexes formed with ions used in fluoroimmunoassays (Ln = Eu, Tb) are also studied in detail. It is noteworthy that subtle variation of the terminal group from benzene to pyridine not only sensibly affects the overall molecular structures but also the luminescence properties as well. 相似文献
8.
Ilichev V. A. Balashova T. V. Polyakova S. K. Rogozhin A. F. Kolybalov D. S. Bashirov D. A. Konchenko S. N. Yablonskiy A. N. Rumyantcev R. V. Fukin G. K. Bochkarev M. N. 《Russian Chemical Bulletin》2022,71(2):298-305
Russian Chemical Bulletin - With the aim of designing new heteroorganic ligands capable of sensitizing the metal-centered photoluminescence (PL) of YbIII through the redox mechanism, a new... 相似文献
9.
《Polyhedron》1999,18(8-9):1141-1145
Exchange reactions of trans-[PdXPh(SbPh3)2] (1) (X=Cl or Br) with ligands L in refluxing dichloromethane give the palladium phenyl complexes [PdXPhL2] (X=Cl, L=PPh3, AsPh3, L2=2,2′-bipyridine (bipy), 4,4′-dimethyl-2,2′-bipyridine (dmbipy), 1,10-phenanthroline (phen); X=Br, L=PPh3, L2=bipy). Treatment of the complexes with bis(diphenylphosphino)methane (dppm) in refluxing dichloromethane gives [PdXPh(dppm]2. These complexes have been characterised by microanalysis, IR and 1H NMR spectroscopic data together with single crystal X-ray determinations of the phenyl palladium complexes, trans-[PdClPh(PPh3)2], [PdClPh(bipy)], [PdClPh(dppm)]2, and [PdBrPh(dppm)]2. 相似文献
10.
Sato T Awano H Haba O Katagiri H Pu YJ Takahashi T Yonetake K 《Dalton transactions (Cambridge, England : 2003)》2012,41(27):8379-8389
We have synthesized a series of platinum (Pt) complexes having a rod-like ligand: 'Pt(F(2)PPy)acac', 'Pt(12F(2)PPy)acac', and 'Pt(12F(2)PPyO4)acac'. The crystal form of Pt(12F(2)PPy)acac was successfully determined to be triclinic by single-crystal X-ray structural analysis. The molecules were parallelly aligned in the unit cell. Monomer and excimer emissions of Pt(12F(2)PPy)acac were observed in hexane solution, poly(methyl methacrylate) film, and various nematic LCs. Homogeneous LC cells with the Pt complex/LC mixtures exhibited polarized optical emission resulting from monomer and excimer states. The PL intensity perpendicular to the orientation direction was higher than the parallel one in the whole wavelength region of the Pt complex and the polarization ratio of the excimer was higher than that of the monomer. The polarization ratios of the excimers were estimated to be 1.4-2.5 in nematic LC at room temperature, and decreased gradually with increasing temperature. The polarization ratios of Pt(12F(2)PPyO4)acac were higher than those of Pt(F(2)PPy)acac and Pt(12F(2)PPy)acac in all the LCs. 相似文献
11.
E. V. Kabin V. A. Emel’yanov V. A. Vorob’yev N. I. Alferova S. V. Tkachev I. A. Baidina 《Russian Journal of Inorganic Chemistry》2012,57(8):1146-1153
The reaction of trans-[RuNO(NH3)4(OH)]Cl2 with nitric acid has been studied. Reaction products have been identified by IR spectroscopy, NMR, mass spectrometry, powder and single-crystal X-ray diffraction, and chemical analysis. Synthesis methods have been developed for amminenitrosoruthenium complexes containing outer-sphere and coordinated nitrate ions: trans-[RuNO(NH3)4(H2O)](NO3)3 (I), trans-[RuNO(NH3)4(NO3)](NO3)2 (II), and fac-[RuNO(NH3)2(NO3)3] (III). Complex II has two polymorphs: monoclinic and tetragonal. The latter has been studied by X-ray crystallography. 相似文献
12.
M. Salehi M. Kubicki G. Dutkiewicz A. Rezaei M. Behzad S. Etminani 《Russian Journal of Coordination Chemistry》2013,39(10):716-722
The synthesis, characterization, spectroscopic and electrochemical properties of trans-[CoIII(L1)(Py)2]ClO4 (I) and trans-[CoIII(L2)(Py)2]ClO4 (II) complexes, where H2L1 = N,N′-bis(5-chloro-2-hydroxybenzylidene)-1,3-propylenediamine and H2L2 = N,N′-bis(5-bromo-2-hydroxybenzylidene)-1,3-propylenediamine, have been investigated. Both complexes have been characterized by elemental analysis, FT-IR, UV-Vis, and 1H NMR spectroscopy. The crystal structure of I has been determined by X-ray diffraction. The coordination geometry around cobalt(III) ion is best described as a distorted octahedron. The electrochemical studies of these complexes revealed that the first reduction process corresponding to Co(III/II) is electrochemically irreversible accompanied by dissociation of the axial Co-N(Py) bonds. The in vitro antimicrobial activity of the Schiff bse ligands and their corrsponding complexes have been tested against human pathogenic bacterias such as Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The cobalt(III) complexes showed lower antimicrobial activity than the free Schiff base ligands. 相似文献
13.
Tang RR Gu GL Zhao Q 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(2):371-376
A novel ligand, N2,N6-bis[2-(3-methylpyridyl)]pyridine-2,6-dicarboxamide (L2) and the corresponding Eu(III) and Tb(III) hydrochlorate complexes have been synthesized and characterized in detail based on elemental analysis, IR and NMR. The crystal and molecular structure of the complexes was determined by X-ray crystallography. The Eu(III) and Tb(III) ions were found to coordinate to the amido nitrogen atoms and pyridine nitrogen atoms. The luminescence properties of lanthanide complexes in solid state, in different solutions and in different pH value were investigated. The result shows that Tb(III) complexes exhibit more efficient luminescence than Eu(III) complexes, and the ligand (L2) is an excellent sensitizer to Tb(III) ion. 相似文献
14.
Orbett T. Alexander Mart M. Duvenhage Alice Brink Hendrik C. Swart Peter Müller R. E. Kroon 《Journal of Coordination Chemistry》2017,70(8):1316-1326
Luminescent gallium(III) complexes featuring 5,7-dimethyl-8-hydroxyquinoline (DimOx) are systematically compared and their structural features are correlated with their photophysical properties. The two complexes are chemically identical; however, contain various number of solvent molecules in the crystalline lattice which is representative of the bulk material confirmed by both nuclear magnetic resonance and elemental analysis. Detailed structural comparisons highlight the effect which the solvent molecules have on the intra- and intermolecular interactions. A distinct number of interactions are found for the gallium complex (1) containing more than one solvent molecule for unit cell. Variation in complex morphology is similarly observed via SEM micrographs. The distinct luminescent properties of the two gallium complexes appear directly related to octahedral coordination of the 8-hydroxyquinoline ligand as well as the number of identical coordinated solvent molecules. 相似文献
15.
M. E. Burin T. V. Balashova D. L. Vorozhtsov A. P. Pushkarev M. A. Samsonov G. K. Fukin M. N. Bochkarev 《Russian Journal of Coordination Chemistry》2013,39(9):667-679
(2-Benzox(thi)azol-2-yl)phenolate and -naphtholate ate complexes of Sc, Y, La, Sm, Tb, and Yb are synthesized. The structure of (benzoxazolyl)phenolate complexes of La, Sm, and Yb are determined by X-ray diffraction analysis. All synthesized compounds manifest ligand-centered photo- and electroluminescence in a range of 510–540 nm. In addition, the spectra of the samarium and terbium complexes exhibit narrow bands of f-f transitions characteristic of Sm3+ and Tb3+ ions. 相似文献
16.
Fei-Long Hu Xian-Hong Yin Yan Mi Shan-Shan Zhang Wei-Qiang Luo 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(2):825-829
Two novel pyrazole-derived ligands, 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinic acid (CDPA) and 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenylpicolinamide (CDPP) were prepared by 3,6-dichloropicolinic acid (DCPA). Their complexes with terbium(III) and europium(III) were synthesized. The complexes were characterized by elemental analysis, infrared spectra, 1H NMR and TG–DTG. Furthermore, the above complexes using 1,10-phenanthroline as a secondary ligand were also synthesized and characterized. The luminescence properties of these complexes in solid state were investigated. The results suggested that Tb(III) complexes exhibit more efficient luminescence than Eu(III) complexes and the fluorescence of the complexes with 1,10-phenanthroline as a secondary ligand was prominently stronger than that of complexes without this ligand., and the three ligand (DCPA), (CDPP) and (CDPA) are excellent sensitizers to Eu(III) and Tb(III) ion. 相似文献
17.
18.
José Vicente Juan Gil‐Rubio Guijiang Zhou Henk J. Bolink Joaquín Arias‐Pardilla 《Journal of polymer science. Part A, Polymer chemistry》2010,48(17):3744-3757
Poly(phenylacetylene)s containing pendant phosphorescent iridium complexes have been synthesized and their electrochemical, photo‐ and electroluminescent properties studied. The polymers have been synthesized by rhodium‐catalyzed copolymerization of 9‐(4‐ethynylphenyl)carbazole (CzPA) and phenylacetylenes (C∧N)2Ir(κ2‐O,O′‐MeC(O)CHC(O)C6H4C?CH‐4) (C∧N = κ2‐N,C1‐2‐(pyridin‐2‐yl)phenyl (IrppyPA) or κ2‐N,C1‐2‐(isoquinolin‐1‐yl)phenyl (IrpiqPA)). In addition, organic poly(phenylacetylene)s with pendant carbazole groups have been synthesized by rhodium‐catalyzed copolymerization of CzPA and 1‐ethynyl‐4‐pentylbenzene. Complex (C∧N)2Ir(κ2‐O,O′‐MeC(O)CHC(O)Ph) (IrpiqPh; C∧N = 2‐(isoquinolin‐1‐yl)phenyl‐κ2‐N,C1) was prepared and characterized. While the copolymers of the Irppy series were weakly phosphorescent, those of the Irpiq series displayed at room temperature intense emissions from the carbazole (fluorescence) and iridium (phosphorescence) emitters, being the latter dominant when the spectra were recorded using polymer films. Triple layer OLED devices employing copolymers of the Irpiq series or the model complex IrpiqPh yielded electroluminescence with an emission spectra originating from the iridium complex and maximum external quantum efficiencies of 0.46% and 2.99%, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3744–3757, 2010 相似文献
19.
Several bis(ligand) octahedral complexes of iron(III) with salicylaldehyde semi-, thiosemi-, and S-methylthiosemi- carbazones have been synthesized and characterized by elemental analysis, conductivity and magnetic measurements, electronic and IR spectra, as well as by linear sweep and cyclic voltammetry. General procedures for the syntheses of all types of complexes have been established, giving better defined reaction conditions. Physicochemical properties of the novel complexes have been related to those of the already known compounds of the same type. 相似文献