共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
The complexes [M(2,2′-bipyridyl)X3], with M = Sb, Bi and X = Cl, Br, I, are characterized by long-wavelength metal-to-ligand charge-transfer (MLCT) bands which determine the colours of these compounds in the solid state. The energy of the MLCT bands depends on the reducing strength of the metal and the extent of sp mixing of the lone electron pair at the metal. 相似文献
3.
Galina L. Starova Anna S. Denisova Evgeniya M. Demyanchuk 《Journal of Molecular Structure》2007,830(1-3):139-142
The structures of 3,3′-dicarbometoxy-2,2′-bipyridine (dcmbpy) complexes with copper(II) and silver(I) cations have been determined using single crystal X-ray-diffraction. The crystals of Cu(dcmbpy)Cl2 are monoclinic, C2/c, a = 16.966(3), b = 18.373(3), c = 13.154(2) Å, β = 126.543(3)°. The crystals of Ag(dcmbpy)NO3 · H2O are also monoclinic, C2/c, a = 16.7547(13), b = 11.0922(9), c = 18.7789(18) Å, β = 100.228(7)°. The results have been compared with the literature data on the complexes of dcmbpy and its precursors: 2,2′-bipyridine (bpy) and 3,3′-dicarboxy-2,2′-bipyridine (dcbpy). Two types of complexes of 3,3′-carboxy derivatives of bpy are distinguished: (1) with metal atom bonded to two N atoms of the same molecule and (2) with metal atom bonded to two N atoms of two different molecules. The Cu(dcmbpy)Cl2 complex belongs to the first type, whereas Ag(dcmbpy)NO3 · H2O belongs to the second type. 相似文献
4.
Zhong Yu Atsuhiro Nabei Takafumi Izumi Takashi Okubo Takayoshi Kuroda‐Sowa 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(5):m209-m212
4′‐Cyanophenyl‐2,2′:6′,2′′‐terpyridine (cptpy) was employed as an N,N′,N′′‐tridentate ligand to synthesize the compounds bis[4′‐(4‐cyanophenyl)‐2,2′:6′,2′′‐terpyridine]cobalt(II) bis(tetrafluoridoborate) nitromethane solvate, [CoII(C22H14N4)2](BF4)2·CH3NO2, (I), and bis[4′‐(4‐cyanophenyl)‐2,2′:6′,2′′‐terpyridine]cobalt(III) tris(tetrafluoridoborate) nitromethane sesquisolvate, [CoIII(C22H14N4)2](BF4)3·1.5CH3NO2, (II). In both complexes, the cobalt ions occupy a distorted octahedral geometry with two cptpy ligands in a meridional configuration. A greater distortion from octahedral geometry is observed in (I), which indicates a different steric consequence of the constrained ligand bite on the CoII and CoIII ions. The crystal structure of (I) features an interlocked sheet motif, which differs from the one‐dimensional chain packing style present in (II). The lower dimensionality in (II) can be explained by the disturbance caused by the larger number of anions and solvent molecules involved in the crystal structure of (II). All atoms in (I) are on general positions, and the F atoms of one BF4− anion are disordered. In (II), one B atom is on an inversion center, necessitating disorder of the four attached F atoms, another B atom is on a twofold axis with ordered F atoms, and the C and N atoms of one nitromethane solvent molecule are on a twofold axis, causing disorder of the methyl H atoms. This relatively uncommon study of analogous CoII and CoIII complexes provides a better understanding of the effects of different oxidation states on coordination geometry and crystal packing. 相似文献
5.
Li Sun J. Ronald Rubin Alan J. Kraker H. D. Hollis Showalter 《Journal of heterocyclic chemistry》1997,34(5):1399-1405
Novel methods for the synthesis of C-5 benzoyl and azido analogues of 2,2′-dithiobis(1H-indole), 1, and 2,2′-diselenobis(1H-indole), 2, are described to further explore the structure activity relationships in this region of the molecule. Analogues 3-i displayed inhibitory activity (IC50 = 0.45-2.03 μ) toward the catalytic domain of the epidermal growth factor receptor tyrosine kinase that was equivalent to or better than that of unsubstituted compounds 1 and 2. The regiochemistry of Friedel-Crafts benzoylation onto 1 was determined by X-ray crystallography. To test the potential for compounds of this class to interact with the epidermal growth factor receptor tyrosine kinase via a sulfhydryl exchange mechanism, reaction of a 2,2′-dithiobis(1H-indole) with glutathione was carried out and the product characterized. 相似文献
6.
The title derivatives were synthesized containing two meso-tri-p-tolylpheneleneporphyrin units attached via amide bridges to 4, 7- and 4,4′ positions of the respective heteroaromatic spacers. 相似文献
7.
B. Jeowska-Trzebiatowska G. Formicka-Kozowska H. Kozowski L. Latos-Grayski T. Kowalik 《Chemical physics letters》1975,30(3):358-362
The NMR method has been used to study the structure of the complexes [Cd(bipy)]SO4.4H2O, [Cd(bipy)](NO3)2.2H2O, [Cd(bipy)2](NO3)2.H2O and [Cd(bipy)3](NO3)2.7H2O. The influence of the central ion and of diamagnetic currents of the rings in these complexes on the PMR spectrum has been investigated. In the complexes [Cd(bipy)](NO3)2.2H2O and [Cd(bipy)]SO4.4H2O two kinds of hydration isomers, with different PMR spectra, have been obtained. 相似文献
8.
Photoinduced Energy Transfer from Poly(N‐vinylcarbazole) to Tricarbonylchloro‐(2,2′‐bipyridyl)rhenium(I)
下载免费PDF全文
![点击此处可从《Chemphyschem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Engelbert Portenkirchner Dogukan Apaydin Gottfried Aufischer Dr. Marek Havlicek Prof. Matthew White Prof. Markus Clark Scharber Prof. Niyazi Serdar Sariciftci 《Chemphyschem》2014,15(16):3634-3638
This work investigates the photoinduced energy transfer from poly(N‐vinylcarbazole) (PVK), as a donor material, to fac‐(2,2′‐bipyridyl)Re(CO)3Cl, as a catalyst acceptor, for its potential application towards CO2 reduction. Photoluminescence quenching experiments reveal dynamic quenching through resonance energy transfer in solid donor/acceptor mixtures and in solid/liquid systems. The bimolecular reaction rate constant at solution–film interfaces for the elementary reaction of the excited state with the quencher material could be determined as 8.8(±1.4)×1011 L mol?1 s?1 by using Stern–Volmer analysis. This work shows that PVK is an effective and cheap absorber material that can act efficiently as a redox photosensitizer in combination with fac‐(2,2′‐bipyridyl)Re(CO)3Cl as a catalyst acceptor, which might lead to possible applications in photocatalytic CO2 reduction. 相似文献
9.
Christina S. Angle Kathryn J. Woolard Michael I. Kahn James A. Golen Arnold L. Rheingold Linda H. Doerrer 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):m231-m234
In the title compound, [PtI(C15H11N3)][AuI2], the [PtI(terpy)]+ cations (terpy is 2,2′:6′,2′′‐terpyridine) stack in pairs about inversion centers through Pt...Pt interactions of 3.5279 (5) Å. The [AuI2]− anions also exhibit pairwise stacking, with Au...I distances of 3.7713 (5) Å. The [PtI(terpy)]+ cations and [AuI2]− anions aggregate forming infinite arrays of stacked ...({[PtI(terpy)]+...[PtI(terpy)]+}...{[AuI2]−...[AuI2]−})... units. 相似文献
10.
Rh(II) acetate binuclear complexes have been reduced by gamma rays to Rh(I) complexes when 2,2′-bipyridine, 2,2′:6′,2″-terpyridine or 1,10-phenantroline ligands are present in aqueous methanol systems. These complexes exist in several forms possessing different absorption spectra. Their concentration depends on the ratio of the initial concentration of the ligands to Rh(II). 相似文献
11.
B. Jeowska-Trzebiatowska H. Kozowski L. Latos-Grayski T. Kowalik 《Chemical physics letters》1975,30(3):355-357
The complexes Zn(bipy)Cl2 and Zn(bipy)2Cl2 as well as 2,2′-bipyridyl in aqueous solution (D2O) have been examined by the NMR method. The presence of the monocationic bipy D+ form in aqueous bipyridyl solution has been found. The changes of chemical shifts of bipyridyl protons for complexes Zn(bipy)3Cl2 and Zn(bipy)Cl2 have confirmed explicitly the essential influence of diamagnetic currents on the NMR spectrum of Zn(bipy)3Cl2. The comparison of the spectra of 2,2′-bipyridyl (in CH3OH) and of Zn(bipy)Cl2 may also suggest the presence of the nonbonding metal-proton 6 interaction. 相似文献
12.
In this paper, we described a simple and rapid method, capillary electrophoresis with electrochemiluminescence (CE–ECL) detection using tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+), to simultaneously detect pethidine and methadone. Analytes were injected to separation capillary of 67.5 cm length (25 μm i.d., 360 μm o.d.) by electrokinetic injection for 10 s at 10 kV. Under the optimized conditions: ECL detection at 1.20 V, 30 mM sodium phosphate (pH 6.0) as running buffer, separation voltage at 14.0 kV, 5 mM Ru(bpy)32+ with 50 mM sodium phosphate (pH 6.5) in the detection cell, the linear range from 2.0 × 10− 6 to 2.0 × 10− 5 M for pethidine and 5.0 × 10− 6 to 2.0 × 10− 4 M for methadone and detection limits of 0.5 μM for both of them were achieved (S/N = 3). Relative standard derivations of the ECL intensity were 2.09% and 6.59% for pethidine and methadone, respectively. 相似文献
13.
The temperature dependence of the emission lifetime of the series of complexes Ru(bpy)n(4,4′-dpb) (bpy = 2,2′bipyridine, 4,4′-dpb = 4,4′-diphenyl-2,2′-bipyridine) has been studied in propionitrile/butyronitrile (4:5 v/v) solutions in the range 90–293 K. The obtained photophysical parameters show that the energy separation between the metal-to-ligand charge tranfer (3MLCT) emitting level and the photoreactive metal-centered (3MC) level changes across the series (ΔE = 3960, 4100, 4300, and 4700 cm?1 for Ru(bpy)), Ru(bpy)2(4,4′-dpb)2+, Ru(bpy)(4,4′-dpb), and Ru(4,4′-dpb), respectively, where ΔE is the energy separation between the minimum of the 3MLCT potential curve and 3MLCT – 3MC crossing point. Comparison between spectral and electrochemical data indicated that the changes in ΔE are due to stabilization of the MLCT levels in complexes containing 4,4′-dpb with respect to Ru(bpy)2+3. The photochemical data for the same complexes (as I? salts) have been obtained in CH2Cl2 in the presence of 0.01M Cl? upon irradiation at 462 nm. The complexes containing 4,4′-dpb are more photostable than Ru(bpy). Comparison between the data for thermal population of the 3MC photoreactive state and those for photochemistry indicated that the overall photochemical process is governed by (i) a thermal redistribution between the emitting and photoreactive excited states, and (ii) mechanistic factors, likely related to the size of the detaching ligand. 相似文献
14.
James A. Dickson Matt M. Ferris Robert E. Milofsky 《Journal of separation science》1997,20(12):643-646
A post- column chemiluminescent technique for thedetection of compounds that are poor chromoshores using electorogenerated chemiluminescence following separation by capillartgy electrophoresis is described. The luminrescent signal is generated followintg the reaction of anlyres (e.g. amines) with Ru(bpy)33+, which isx electrochemically generated post-columan from Ru(bpy)32+. Tripropylamine and proline are used as two model compounds to demostrate the feasibility of the method. Detection limits for the prototype system were in the micromolar rage, suggesting that this technnique offers an alternative to indirect detection of compounds that are poor chromophores with an added selectivity advangage. The system includes the use of a conductive joint to isolate the separation field from the potential necessary to drive the elctrogenerated chemiluminescent reactiion. Addition of the chemiluminescent reagent Ru(bpy)32+ post-column did not decrease the efficiency of the separation. The design and favrication of the novel cell is discussed. 相似文献
15.
Alexander N. Chernyshev Vadim Yu. Kukushkin Matti Haukka 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(12):1133-1137
Two noble metal complexes involving ancillary chloride ligands and chelating 2,2′‐bipyridylamine (Hdpa) or its deprotonated derivative (dpa), namely [bis(pyridin‐2‐yl‐κN)amine]tetrachloridoplatinum(IV), [PtCl4(C10H9N3)], and [bis(pyridin‐2‐yl‐κN)aminido]dichloridogold(III), [AuCl2(C10H8N3)], are presented and structurally characterized. The metal atom in the former has a slightly distorted octahedral coordination environment, formed by four chloride ligands and two pyridyl N atoms of Hdpa, while the metal atom in the latter has a slightly distorted square‐planar coordination environment, formed by two chloride ligands and two pyridyl N atoms of dpa. The difference in conjugation between the pyridine rings in normal and deprotonated 2,2′‐dipyridylamine is discussed on the basis of the structural features of these complexes. The influence of weak interactions on the supramolecular structures of the complexes, providing one‐dimensional chains of [PtCl4(C10H9N3)] and dimers of [AuCl2(C10H8N3)], are discussed. 相似文献
16.
Masao Kaneko Masahisa Ochiai Kazuhiko Kinosita Akira Yamada 《Journal of polymer science. Part A, Polymer chemistry》1982,20(4):1011-1019
The characteristics of the photoinduced electron transfer reaction from polystyrene pendant tris(2,2′-bipyridyl)ruthenium (II) complex [Ru(bpy)] to methylviologen (MV2+) were studied. The rate constant k1 from the excited state of the complex, Ru(bpy), to MV2+ were determined for both the polymeric and monomeric complexes from the lifetime τ of Ru(bpy) and the quenching rate of Ru(bpy) by MV2+. The polymer pendant Ru(bpy) showed three kinds of τ components ranging from 7 to 474 ns, in contrast to the monomeric complex, which showed one component of 350 ns. The k1 values for both complexes were almost the same, on the order of 108 L/mol s. The photoinduced electron transfer from solid-phase Ru(bpy) to liquid-phase MV2+ was realized by utilizing the polymer complex, and the solid–liquid interphase reaction system is discussed. 相似文献
17.
18.
19.
20.
Ren M. Williams Luisa De Cola Frantisek Hartl Jean-Jacques Lagref Jean-Marc Planeix Andr De Cian Mir Wais Hosseini 《Coordination chemistry reviews》2002,230(1-2):253-261
The synthesis, solution and solid state structural characterization, photophysical and electrochemical properties of two redox forms of an electrochromic copper-bis(4,4′-dimethyl-6,6′-diphenyl-2,2′-bipyridine) complex, [Cu(3)2]n (n=+1, +2), are presented. Both complexes were characterized in the solid state by X-ray diffraction methods on single-crystals showing that both forms exist in a pseudo-tetrahedral coordination, and a comparison with other structures was made. Like most copper(I) complexes, the red [Cu(3)2]+ complex shows a rather weak emission (Φem=2.7×10−4, dichloromethane). The lifetime of the emitting MLCT state is 34±1 ns, as observed with time resolved emission, and transient absorption (in deoxygenated dichloromethane). Typical emission and transient absorption spectra are presented. The transient absorption spectra indicate that the MLCT state absorbs stronger than the ground state, which is relatively uncommon for metal bipyridine complexes, i.e. no ground state bleaching is observed. The green [(3)2Cu]2+ complex does not show any observable emission or transient absorption, which is a common feature for Cu(II) complexes of this type. The electronic absorption spectra of the chemically and electrochemically produced copper(I/II) complexes are identical. The repeated electrochemical conversion of the Cu(I) center into Cu(II) and vice versa does not cause any decomposition. This is consistent with a fully reversible Cu(I)/Cu(II) redox couple in the corresponding cyclic voltammogram, (E1/2 (Cu(I)/Cu(II))=+0.68 V vs. SCE=+0.23 V vs. Fc/Fc+). These observations indicate that no large structural reorganization occurs upon electrochemical timescales (sub second), and that the different ways of generating the complexes does not effect their final structure, apart from the small differences observed in the X-ray structures of both forms. These characteristics make these complexes rather well suited for their incorporation into an electrochromic display configuration. 相似文献