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1.
Preparation methods are developed for a number of 7- and 8-coordinated derivatives of Hf(IV) and Zr(IV) with β-diketonate ligands (R1-CO-CH-CO-R2). The complexes obtained are examined by IR spectroscopy, mass spectrometry, and X-ray crystallography. All structures are molecular. The M-O distances fall within 2.09–2.28 Å. In the crystals, the molecules are joined only by van der Waals interactions. It is demonstrated that the series of hafnium(IV) and zirconium(IV) chelates with identical ligands are isostructural, and the introduction of CF3- or tert-butyl groups in the terminal positions of the ligand as well as chlorine substitution for one of the ligands do not essentially affect the basic geometric characteristics of the ligand in the complexes.  相似文献   

2.
By means of a tensiometric flow method and a static method with a silica-membrane zero gauge, the dependences of saturated vapour pressure on temperature were obtained for the complexes of zirconium(IV) with acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, dipivaloylmethane and pivaloyltrifluoroacetone. The thermodynamic characteristics of the evaporation and sublimation of these complexes were determined.  相似文献   

3.
The electronic absorption (EAS) and fluorescence spectra and electrocatalytic and photoelectrochemical characteristics of mixed-ligand complexes of zirconium(IV) and hafnium(IV) based on phthalocyanines in solutions and in thin films were investigated. It was established that a significant bathochromic shift of the Q band and redistribution of the intensities in the absorption bands are observed in the electronic absorption spectra. It was shown that films of the synthesized compounds are promising for use as photosensitizers and electrochemical sensors for oxygen in solution. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 44, No. 3, pp. 133–137, May–June, 2008.  相似文献   

4.
The structure and thermal properties of a novel zirconium(IV) complex with a methoxy substituted β-diketonate ligand tetrakis-(2-methoxy-2,6,6-trimethylheptane-3,5-dionato)zirconium are described. The complex sublimes without decomposition under low pressure (10–2 Torr) at 200 °C. The crystal structure of the complex is molecular and is composed of two structural Zr(zis)4 isomers in a 1:1 ratio. The crystallographic data are as follows: C88H152F24O24Zr2, P-1, a = 12.1350(7) Å, b = 19.7733(10) Å, c = 21.0526(12) Å, α = 83.338(2)°, β = 89.571(2)°, γ = 73.515(2)°, V = 4809.5(5) Å3, Z = 2, d = 1.227 g/cm3. The coordination environment of the zirconium atom consists of eight oxygen atoms from four β-diketonate ligands; the coordination polyhedron is a square antiprism. The Zr–O distances are in a range 2.127-2.202 Å. The thermal properties of the complex are studied by TG–DTA. The effect of the crystal structure (molecular packing) on the volatility and thermal properties is compared for the new complex and two other analogous zirconium complexes with β-diketonate ligands containing bulky terminal substituents. The results of the mass spectrometric study of thermal behavior of the complexes on programmed heating of vapor under the conditions similar to those in a hot wall CVD reactor under low pressure, including the decomposition in the presence of oxygen, are discussed.  相似文献   

5.
The structures of volatile pyridine adducts of trimethylplatinum(IV) β-diketonates derived from acetylacetone (Hacac) and dipivaloylmethane (Hdpm) are studied for the first time. Their preparation is reported and the data of thermal studies obtained by the DTA technique are presented. The structures of the compounds in question comprise monomeric complexes. The platinum atom is coordinated to three carbon atoms of methyl groups, two oxygen atoms of β-diketone, and the nitrogen atom of the pyridine molecule. The (PtC3O2N) coordination core has the shape of a slightly distorted octahedron. The geometrical characteristics of the coordination cores are the following: in all complexes, the values of Pt-O, Pt-CMe, Pt-N bond lengths and O-Pt-O chelate angles fall within 2.122–2.146 Å, 1.986–2.079 Å, 2.131–2.186 Å and 89.3–90.6° respectively.  相似文献   

6.
Volatile fluorinated trimethylplatinum(IV) β-diketonates with pyridine (CH3)3Pt(CH3-CO-CH-CO-CF3)Py (I) and (CH3)3Pt(CF3-CO-CH-CO-CF3)Py (II) obtained from trifluoroacetylacetone and hexafluoroacetylacetone were studied. The synthesis, elemental analysis data, and IR spectra were described. X-Ray diffraction analysis was performed and the crystal structure was determined; the geometric characteristics of complexes I and II were obtained. Both structures are monomeric molecular structures. The molecules in the crystal are connected only by weak van der Waals forces. The coordination polyhedron of platinum in I and II is a slightly distorted octahedron. The shortest Pt…Pt distances are 6.639 Å (for I) and 6.254 Å (for II). The average P-O, Pt-N, and P-C distances are 2.157, 2.182, and 2.030 Å, respectively. The deviations of the bond angles at Pt atoms from ideal values of 90° do not exceed 4.8°.  相似文献   

7.
Three novel complexes of zirconium(IV) are prepared and characterized by single crystal X-ray diffraction: zirconium(IV) pivaloyltrifluoroacetonate Zr(ptac)4, zirconium(IV) trifluoroacetylacetonate Zr(tfac)4, and zirconium(IV) hexafluoroacetylacetonate Zr(hfac)4. Crystal data for C32H40F12ZrO8: a = 19.9842(6) Å, b = 11.8417(3) Å, c = 16.4831(5) Å; β = 95.2880(10)°, monoclinic, space group Cc, Z = 4, d calc = 1.491 g/cm3, R = 0.061. Crystal data for C20H16F12ZrO8: a = 21.5063(15) Å, b = 7.9511(5) Å, c = 16.0510(10) Å; β = 113.736(4)°, monoclinic, space group C2/c, Z = 4, d calc = 1.860 g/cm3, R = 0.047. Crystal data for C20H4F24ZrO8: a = 15.3533(13) Å, b = 20.2613(15) Å, c = 19.6984(17) Å; β = 95.828(2)°, monoclinic, space group P21/c, Z = 2, d calc = 2.004 g/cm3, R = 0.078. All the structures are molecular and include isolated mononuclear Zr(β-dik)4 complex molecules. Coordination environment of zirconium atom is made by eight oxygen atoms of four β-diketonates; the coordination polyhedron is an almost regular square antiprism. The Zr-O distances fall within 2.14–2.23 Å. Complexes in the structures are joined by van der Waals interactions. Using the structural data, the van der Waals energies of crystal lattices of the studied compounds are calculated by the atom-atom potential method.  相似文献   

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9.
The interaction of 5,10,15,20-tetraphenylporphyrin, 5,10,15,20-tetra-(4-chlorophenyl)porphyrin, 2-bromo-5,10,15,20-tetraphenylporphyrin, and 2,3,12,13-tetrabromo-5,10,15,20-tetraphenylporphyrin with platinum(II) chloride in boiling phenol has been studied. The corresponding platinum(II) porphyrinates have been synthesized; their subsequent treatment with bromine in chloroform resulted in platinum(IV) porphyrinates. The Pt(II) and Pt(IV)(Br)2 porphyrinates have been identified by elemental analysis, electron absorption, IR, and 1H NMR spectroscopy.  相似文献   

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13.
Chloro-, bromo- and iodocomplexes of hafnium(IV) have been studied by the TTA extraction, liquid cation exchanger, and resinous cation exchanger methods at ionic strength of 3·0 M. The existence of the HfX3+ (X  Cl, Br, I) and HfX22+ (X Cl, Br) species has been confirmed and their stability constants measured. The bonding in the HfX3+ species has been discussed.  相似文献   

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15.
The effect of the mechanical treatment conditions and of the nature of reactants on the course of the solid-phase reaction of vanadium(III) chloride with sodium β-diketonates and potassium tetramethylheptanedionate, on the yield of the reaction products, and on some properties of the activated mixtures was examined. A method was developed for the synthesis of vanadium(III) β-diketonates by the solid-phase mechanochemical reaction of vanadium(III) chloride with appropriate sodium or potassium β-diketonate, followed by sublimation or extraction.  相似文献   

16.
Interaction between tin tetrachloride and p-fluorobenzoylacetone and 2-thenoyltrifluoroacetone in cold benzene afforded, insoluble ion-pair complexes of the type [Cl2SnL2]Sn2+Cl62−1. The same system in refluxing benzene yielded soluble covalent derivatives of the type X2SnL2 (where X = Cl, Br, I and L = p-fluorobenzoylacetonate and 2-thenoyltrifluoroacetonate anion). Based on the physical properties and spectral measurements these derivatives were shown to possess octahedral structure.  相似文献   

17.
Formation of copper -diketonates in electrolysis of a solution of acetylacetone in acetonitrile in the presence of oxygen, with tetraethylammonium bromide as supporting electrolyte, was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 11, 2004, pp. 1804–1807.Original Russian Text Copyright © 2004 by Kostyuk.  相似文献   

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19.
A spectrophotometric study of the titanium-, zirconium-, hafnium-, and thorium-naphthazarin systems in absolute ethanol using the method of continuous variations, indicates compositions with metal to ligand ratios between 1:1 and 1:2. Formation constants are calculated for these systems on the assumption that there is an equilibrium between 1:1 and 1:2 species absorbing at the same wavelength. The formation constants for both the 1:1 and 1:2 complexes are in the order: Th > Zr > Hf > Ti. A similar study of the same metals with β-hydronaphthazarin shows that titanium, zirconium, and thorium form complexes with the same composition as the naphthazarin complexes, but that hafnium forms only a 1:1 complex. The formation constants of the 1:1 complexes are in the order: Ti > Th > Zr > Hf; while those of the 1:2 complexes are: Th > Ti > Zr. The complexes formed by both ligands with the tripositive rare earth ion, neodymium, are of the same type as the Group IV complexes, and formation constants have been calculated.  相似文献   

20.
Interaction between Eu(III) tris(β-diketonates) and ammonia vapors increases the luminescence of Eu(III). A mechanism for the effect of analyte molecules on the intensification of Eu(III) luminescence is proposed. The mechanism includes the displacement of water molecules from the coordination sphere of europium(III).  相似文献   

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