共查询到20条相似文献,搜索用时 15 毫秒
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Russian Journal of General Chemistry - 相似文献
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E. V. Ivanova M. V. Puzyk K. P. Balashev 《Russian Journal of General Chemistry》2009,79(10):2096-2101
Biscyclometallated [(M(N∧N))2(μ-dphpm)](ClO4)2 and [(N∧N)Pd(μ-dphpm)Pt(N∧N)]Cl2 complexes [M = Pd(II), Pt(II); (N∧N) ethylenediamine (En), 1,10-phenanthroline (phen); dphpm2 — bisdeprotonated form of 4,6-diphenylpyrimidine)] have been characterized by the 1H NMR, electronic absorption and emission spectroscopy, and also cyclic voltammetry methods. The lowest unoccupied molecular
orbital (LUMO) of biscyclometallated complexes with ethylenediamine, responsible for low-energy photo- and electro-stimulated
processes irrespective of the metal nature, is assigned to the π* orbital mainly localized on the pyrimidine part of the bridging
ligand. In the case of complexes with phenanthroline chelating ligands, the replacement of one or two palladium metal centers
[{Pd(phen)}2(μ-dphpm)]2+ by platinum centers changes the LUMO nature of the complexes for the π* orbital mainly localized on the peripheral metal-complex
fragment {Pt(phen)}. 相似文献
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Panova A. G. Radyushin K. A. Balashev K. P. 《Russian Journal of General Chemistry》2011,81(4):743-746
Complexes [Pd(bt)En]ClO4, [Pd(bt)(μ-OOCCH3)]2, [(PdEn)2(μ-dbt)](CH3COO)2, and [Pd2(μ-dbt)· (μ-OOCCH3)2]2 (bt− and dbt2− are the mono- and bisdeprotonated forms of 2-phenylbenzothiazole and 1,4-bis-(benzthiazol-2-yl)benzene, En is ethylenediamine)
are characterized by 1H NMR, electron absorption spectroscopy, and voltammetry. The upfield shift of the signal of protons of heterocyclic ligands
in complexes with acetate ligands is assigned to anisotropic effect of the ring current of the two fragments {Pd(bt)} and
{Pd(dbt)} in the complexes. The red shift of the optical transition of the metal-ligand charge transfer as well as the anodic
shift of the ligand-centered reduction of [(PdEn)2(μ-dbt)](CH3COO)2 relative to [Pd(bt)En]ClO4 is due to the decrease in the LUMO energy of the complexes. The cathodic shift of the oxidation potential and the long wavelength
absorption in complexes with acetate ligands is assigned to variation in the HOMO nature due to the metal-metal bond formation. 相似文献
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Romanova I. P. Yusupova G. G. Yakhvarov D. G. Larionova O. A. Mochul"skaya N. N. Sidorova L. P. Charushin V. N. Zverev V. V. Sinyashin O. G. 《Russian Chemical Bulletin》2003,52(10):2171-2174
The first representative of the pyrimidine-substituted [60]fullereno[1,2-b]aziridines was synthesized by the reaction of fullerene C60 with 2-azido-4,6-diphenylpyrimidine. 2-(Azahomo[60]fullereno)-4,6-diphenylpyrimidine was found to be formed as a by-product. The electrochemical properties of the adducts were studied. 相似文献
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The proligand 4,6-di-(4-tert-butylphenyl)pyrimidine LH(2) can undergo cycloplatination with K(2)PtCl(4) at one of the two aryl rings to give, after treatment with sodium acetylacetonate, a mononuclear complex Pt(N^C-LH)(acac) (denoted Pt). If an excess of K(2)PtCl(4) is used, a dinuclear complex of the form [Pt(acac)](2){μ-(N^C-L-N^C)} (Pt(2)) is obtained instead, where the pyrimidine ring acts as a bridging unit. Alternatively, the mononuclear complex can undergo cyclometalation with a different metal ion. Thus, reaction of Pt with IrCl(3)·3H(2)O (2:1 ratio) leads, after treatment with sodium acetylacetonate, to an unprecedented mixed-metal complex of the form Ir{μ-(N^C-L-N^C)Pt(acac)}(2)(acac) (Pt(2)Ir). The mononuclear iridium complex Ir(N^C-LH)(2)(acac) (Ir) has also been prepared for comparison. The UV-visible absorption and photoluminesence properties of the four complexes and of the proligand have been investigated. The complexes are all highly luminescent, with quantum yields of around 0.5 in solution at room temperature. The introduction of the additional metal centers is found to lead to a substantial red-shift in absorption and emission, with λ(max) in the order Pt < Pt(2) < Ir < Pt(2)Ir. The trend is interpreted with the aid of electrochemical data and density functional theory calculations, which suggest that the red-shift is due primarily to a progressive stabilization of the lowest unoccupied molecular orbital (LUMO). The radiative decay constant is also increased. This versatile design strategy may offer a new approach for tuning and optimizing the luminescence properties of d-block metal complexes for contemporary applications. 相似文献
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Lentijo S Miguel JA Espinet P 《Dalton transactions (Cambridge, England : 2003)》2011,40(29):7602-7609
Mononuclear palladium complexes [Pd(C^N)L(2)] (HC^N = 3-C(20)H(11)CH=NC(6)H(4)-p-C(2)H(5)) have been prepared with Pd bound to the peri site or to the ortho site of the perylenyl fragment. These metallations correspond, respectively to six-membered (L(2) = S(2)COMe (3); acac (4); Cl, PMe(3) (5); Cl, PPh(3) (6); S(2)CNEt(2) (7)) or five-membered (L(2) = S(2)COMe (8); acac (9)) isomeric palladacyclic compounds. The X-ray structures of 3, 5, 7 and 8 show that the perylenyl fragment remains essentially flat for 3, 7 and 8 and twisted for 5. Intermolecular π-π stacking of perylenyl rings is observed only for 7. All palladium complexes exhibit fluorescence associated to the perylene fragments, with emission quantum yields (in solution at room temperature) in the range 0.01-0.12 (compared to 0.13 for the free imine), and emission lifetimes ~ 1 ns. The complexes with five-membered palladacycles show lower quantum yields than their six-membered analogs. The similarity in shape of the luminescence spectra of these metallated complexes with perylene, although red-shifted, strongly suggests a perylene-dominated intraligand π-π* emissive state, metal-perturbed by interaction of the perylene orbitals with the palladium fragment. 相似文献
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Mancilha FS Barloy L Rodembusch FS Dupont J Pfeffer M 《Dalton transactions (Cambridge, England : 2003)》2011,40(40):10535-10544
The cyclopalladation of the 4-aryl-2,1,3-benzothiadiazoles 1a-c with palladium acetate in acetic acid afforded the novel dimeric complexes 2a-c in good yields. These were then converted into the monomeric pyridine-, chloro-coordinated cyclometallated complexes 3a-c through reaction with lithium chloride in acetone and then pyridine in dichloromethane. All complexes were fully characterized by means of NMR, IR and elemental analysis. The X-ray structure of complex 2c revealed that it presents transoid geometry, whereas the X-ray structure of 3c shows that the pyridine ligand and the thiazole ring are mutually trans. Photophysical properties were investigated by means of UV-Vis absorption and fluorescence emission in solution. Solid-state diffuse reflectance UV-Vis spectra (DRUV) were also applied in order to better characterize the complexes photophysics in the solid state. All complexes present intense absorption at around 300 nm (λ(1)) via(1)LC transitions located in BTD ligands, and additional low energy absorption bands, higher than 450 nm (λ(2)) of (1)MLCT character. The complexes are fluorescent in solution at room temperature, where two emission bands could be observed, a high energy band (excitation @ λ(1)) ascribed to the ligand emission and an additional red shifted low intense band (excitation @ λ(2)) due to the complex emission. 相似文献
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T. V. Rybalova V. F. Sedova I. Yu. Bagryanskaya Yu. V. Gatilov O. P. Shkurko 《Chemistry of Heterocyclic Compounds》2001,37(2):206-211
The crystal structures of 6-chloro-4-nitro-2-phenylpyrimidine and 6-chloro-2-phenylpyrimidine have been determined using X-ray diffraction. The effect of the nitro group and the endocyclic nitrogen atoms on the geometric parameters of the 2- and 4-nitropyrimidine molecules, and also related -nitroazines are compared. 相似文献
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Harutyunyan A. A. Israyelyan S. G. Panosyan H. A. Safaryan M. S. Dilanyan S. V. 《Russian Journal of Organic Chemistry》2020,56(9):1588-1594
Russian Journal of Organic Chemistry - 4-(4-Aminophenyl)-2,6-diphenylpyrimidine was synthesized by reaction of (E)-1-(4-aminophenyl)-3-phenylprop-2-en-1-one with benzamidine and was involved in a... 相似文献
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O. A. Zalevskaya E. G. Vorob’eva I. A. Dvornikova A. V. Kuchin 《Russian Journal of Coordination Chemistry》2008,34(11):855-857
Novel chiral palladium diamino complexes with the asymmetric donor N atom Pd(En*)X2 (where En* = N,N′-bis{[(1S,5R)-6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl]methyl}-1,2-ethylenediamine; X = Cl and Br) were obtained and characterized. Nitrogen-containing derivatives of the natural monoterpene a-pinene were studied as accessible optically active ligands. 相似文献
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Rodionova O. A. Finagenova G. O. Puzyk M. V. Balashev K. P. 《Russian Journal of General Chemistry》2010,80(2):370-371
Russian Journal of General Chemistry - 相似文献
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The review is devoted to synthesis and study of interfacial properties of electrostatic complexes between oppositely charged chitin derivatives and surfactants, so-called surfactant-polyelectrolyte complexes (SPECs). The ordered nanostructure of insoluble SPEC found by small-angle X-ray scattering (SAXS) looks as a physical gel network formed by micelle-like aggregates interconnected by macro-molecular chains. Viscoelastic properties of such gels were studied by means of the Hertz method and interfacial dilational rheology. A new method based on the effect of diffusion-enhanced gelation at the interface of aqueous solutions of oppositely charged polyelectrolytes and surfactants was developed. This method makes it possible to produce microcapsules containing enzymes, i.e. microreactors for enzymatic catalysis. 相似文献
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A. Ya. Tikhonov V. F. Sedova L. B. Volodarskii V. P. Mamaev 《Chemistry of Heterocyclic Compounds》1981,17(4):383-386
2-Chloropyrimidine 1-oxides are formed in the reaction of substituted 4-phenylpyrimidine 1,3-dioxides with phosphorus oxychloride; in addition, 2,4-dichloropyrimidines and 3-phenylisoxazoles were isolated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 526–529, April, 1981. 相似文献
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The thermal dehydration and deamination of some ethylenediamine complexes of Zn, Cd, Cu, Ni and Co oxalate were studied by TGA, DTA, DSC, reflectance spectroscopy, and by GE. The tris(amine) complexes deaminated to mono(amine) compounds which then decomposed directly to the metal oxide. The kinetics and heats of dehydration and deamination of several of the complexes were determined. 相似文献
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Cyclopalladated complexes catalyzed addition of arylboronic acids to aldehydes in neat water 总被引:1,自引:0,他引:1
Cyclopalladated ferrocenylimine complexes gave high yields for the addition of arylboronic acids with aldehydes in neat water using a weak acid as additive. 相似文献
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Copper complexes of ethylenediamine (en), N-methylethylenediamine (meen), N,N-dimethylethylenediamine (dmen), N,N,N'-trimethylethylenediamine (tren), and N,N,N',N'-tetramethylethylenediamine (tmen) are synthesized in laser-vaporization supersonic molecular beams and studied by pulsed-field ionization zero electron kinetic energy (ZEKE) and photoionization efficiency spectroscopies and second-order Moller-Plesset perturbation theory. Precise ionization energies and vibrational frequencies of Cu-en, -meen, and -dmen are measured from the ZEKE spectra, and ionization thresholds of Cu-tren and -tmen are estimated from the photoionization efficiency spectra. The measured vibrational modes span a frequency range of 35-1646 cm(-1) and include metal-ligand stretch and bend, hydrogen-bond stretch, and ligand-based torsion. A number of low-energy structures with Cu binding to one or two nitrogen atoms are predicted for each complex by the ab initio calculations. The combination of the spectroscopic measurements and ab initio calculations has identified a hydrogen-bond-stabilized monodentate structure for the Cu-en complex and bidentate cyclic structures for the methyl-substituted derivatives. The change of the Cu binding from the monodentate to the bidentate mode arises from the competition between copper coordination and hydrogen bonding. 相似文献
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Changes in the stability of the cadmium(ii) ethylenediamine complexes in mixed water—DMSO solvents were studied by pH-metry and calorimetry. Complex cations [Cd(en)]2+, [Cd(en)2]2+, and [Cd(en)3]2+ are formed in aqueous solutions, and the [Cd(en)4]2+ complex with a partially dentate ligand is stable in DMSO. An increase in the DMSO content in a solvent increases the stability of the complexes. The maximum increase in logK is observed for coordinatively saturated compounds. The thermodynamics of complexation is discussed from the viewpoint of solvation approach. Principal differences in the influence of aqueous-alcohol and aqueous-aprotic solvents on the stability of the metal amino complexes were revealed. Protolytic solvents exert a destabilizing effect on the multiligand complexes, because the coordination sphere is involved in H bonding. 相似文献