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1.
本文报道了在焦磷酸盐的碱性水溶液中用O~3氧化Pr(III)和Tb(III),从而得到Pr(IV)-P~2O~7^4^-和Tb(IV)-P~2O~7^4^-的配合物溶液,通过对溶液进行化学分析及吸收光谱的研究,证明了溶液中有Pr(IV)和Tb(IV)的存在,其持征吸收分别为λmax=365nm,摩尔消光系数ε=1205L/mol.cm;/.pr(iv)=257nm,ε=929L/mol.cm.在碱性条件下,Pr(IV)和Tb(IV)的还原反应均为拟一级反应.用动力学方法测定了不同条件下Pr(IV)和Tb(IV)的还原速率常数和半衰期,从而探讨了稳定Pr(IV)和Tb(IV)的条件.同时还测定了在反应条件下Pr(IV)/Pr(III)和Tb(IV)/Tb(III)电对的克式电位。 相似文献
2.
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
3.
Tomachinskaya L. A. Kolotilova Yu. Yu. Chernii V. Ya. Volkov S. V. 《Theoretical and Experimental Chemistry》2003,39(2):104-108
We have used cyclic voltammetry to study the electrochemical properties of novel bis(-diketonate)phthalocyanine complexes of Zr(IV) and Hf(IV) in dichloromethane. We found three waves for the studied complexes that can be attributed to one-electron processes MPc(L)0/1–
2, MPc(L)1+/0
2 and MPc(L)2+/1+
2. We have shown that the electrochemical behavior of the complexes depends on the nature of the substituents in axial ligands and does not depend on the nature of the metals. We have analyzed the stability of the one-electron oxidation products of the complexes relative to disproportionation. 相似文献
4.
Irena Bajc Svetozar Milićev Bogdan Volavšek 《Monatshefte für Chemie / Chemical Monthly》1992,123(4):321-324
Summary The microcristalline phase (NH3OH)2TiF6 has been isolated from aqueous solution. It crystallizes in the tetragonal system with cell parameters:a=9.654±0.005 Å,c=11.546±0.010 Å. The hydroxylammonium fluorotitanate was characterized by vibrational spectroscopy and its thermal decomposition studied by DSC and TG analysis. 相似文献
5.
Luciana S. Guinesi C. A. Ribeiro Marisa S. Crespi A. F. Santos Marisa V. Capela 《Journal of Thermal Analysis and Calorimetry》2006,85(2):301-307
This work aims the evaluation of the kinetic triplets
corresponding to the two successive steps of thermal decomposition of Ti(IV)–ethylenediaminetetraacetate
complex. Applying the isoconversional Wall–Flynn–Ozawa method
on the DSC curves, average activation energy: E=172.4±9.7
and 205.3±12.8 kJ mol–1, and pre-exponential
factor: logA=16.38±0.84 and 18.96±1.21
min–1 at 95% confidence interval could be
obtained, regarding the partial formation of anhydride and subsequent thermal
decomposition of uncoordinated carboxylate groups, respectively.
From E and logA values,
Dollimore and Málek methods could be applied suggesting PT (Prout–Tompkins)
and R3 (contracting volume) as the kinetic model to the partial formation
of anhydride and thermal decomposition of the carboxylate groups, respectively. 相似文献
6.
Sharma Neeraj Sood Anoop K. Bhatt Sarvjeet S. Kalia Shashi B. Chaudhry Subhash C. 《Transition Metal Chemistry》1998,23(5):557-560
Complexes of composition [VCl(acac)2(OAr1–4)] and [V(acac)2(OAr1–4)2] (HOAr1=HOC6H4NO2–4, HOAr2= HOC6H4OMe-4, HOAr3=HOC6H4But-4 and HOAr4= HOC6H2But-2,6–Me-4; acac=2,4–pentanedionato ion) have been synthesized by the reaction of [VCl2(acac)2] with the respective phenols or their trimethylsilyl derivatives. The complexes have been characterized by physicochemical and spectroscopic techniques. They are non-electrolytes in nitrobenzene. Room temperature magnetic moments in the 1.71–1.82B range are consistent with the VIV system. The reactions of [VCl(acac)2(OAr2)] and [VCl(acac)2(OAr3)] with chloride acceptors have been studied by conductance techniques and the formation of ionic complexes of the types [V(acac)2(OAr2,3)][MCl4] (M=Fe, Al or Sb) and [V(acac)2(OAr2,3)][MCl6] (M=P or Sb) is indicated by the conductance composition curves. Several of these complexes have been isolated and characterized. 相似文献
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8.
Suraj P. Narula Sajeev Soni Meenu Puri Rishi D. Anand Jugal K. Puri 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1647-1654
Si(NHC6H5-nFn)4.xTiCl4 [n = 2–5; x = 3,4] are obtained from the disproportionation reactions between (CF3CH2O)3SiNHC6H5-nFn (n = 2–5) and TiCl4 in petroleum ether (40–60°C) at 0°–10°C. These complexes are characterized by elemental analyses and IR, 1H, and 19F NMR spectroscopy. Unlike the reported5 complex Si(NHC6H4F-o)4.3TiCl4, these are non-ionic in nature. All complexes give double adducts with CH3NO2 and CH3CN within 24 h. 相似文献
9.
《Journal of organometallic chemistry》1988,346(1):C31-C34
It is shown that photolysis of [PtMe4(bipy)] using incident radiation with λ 436 or 473 nm occurs with high quantum efficiency of 0.8–1.0 to give homolysis of a methylplatinum bond; this has allowed a study of the chemical reactions of the [PtMe3(bipy)] radical. 相似文献
10.
Teresa Kowalik-Jankowska Henryk Kozlowski Karol Kociolek Miroslaw T. Leplawy Giovanni Micera 《Transition Metal Chemistry》1995,20(1):23-25
Summary Potentiometric and spectroscopic measurements were used to characterize the binding ability of -hydroxy-methylserine (Hms) with copper(II) and oxovanadium(IV) ions. The ligand was found to be generally a more efficient chelating agent than serine. Both of the deprotonated hydroxyl groups of Hms can be involved in coordination to vanadyl ions, whereas copper(II) binds in the same way as with serine. 相似文献
11.
Dr. Apparao Draksharapu Waqas Rasheed Dr. Johannes E. M. N. Klein Prof. Dr. Lawrence Que Jr. 《Angewandte Chemie (International ed. in English)》2017,56(31):9091-9095
Ceric ammonium nitrate (CAN) or CeIV(NH4)2(NO3)6 is often used in artificial water oxidation and generally considered to be an outer-sphere oxidant. Herein we report the spectroscopic and crystallographic characterization of [(N4Py)FeIII-O-CeIV(OH2)(NO3)4]+ ( 3 ), a complex obtained from the reaction of [(N4Py)FeII(NCMe)]2+ with 2 equiv CAN or [(N4Py)FeIV=O]2+ ( 2 ) with CeIII(NO3)3 in MeCN. Surprisingly, the formation of 3 is reversible, the position of the equilibrium being dependent on the MeCN/water ratio of the solvent. These results suggest that the FeIV and CeIV centers have comparable reduction potentials. Moreover, the equilibrium entails a change in iron spin state, from S=1 FeIV in 2 to S=5/2 in 3 , which is found to be facile despite the formal spin-forbidden nature of this process. This observation suggests that FeIV=O complexes may avail of reaction pathways involving multiple spin states having little or no barrier. 相似文献
12.
A. A. S. Elkhaldy A. R. Hussien A. M. Abu Shanab M. A. Wassef 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):589-597
Abstract Reactions of O,O′-dialkyl and alkylene dithiophosphoric acids with bis (cyclopentadienyl) titanium(IV) and zirconium (IV) dichloride in a 1:1 molar ratio in refluxing benzene proceeds with elimination of HCl and formation of the substituted derivatives, Cp2MCl[S2P(OR)2] (where R = Et, Pr-n, Pr-i, Bu-i and Ph), Cp2MCl[S2POGO] (where G = ?CH2CMe2CH2?, ?CH2CEt2CH2? and ?CMe2CMe2?), (M = Ti and Zr). The complexes are dark red and yellow solids, soluble in common organic solvents and monomeric in nature. These have been characterized on the basis of elemental analyses, molecular weight determinations, IR, and NMR (1H, 13C, and 31P). GRAPHICAL ABSTRACT 相似文献
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14.
15.
L. A. Tomachinskaya I. N. Tret’yakova V. Ya. Chernii G. Ya. Kolbasov V. S. Vorobets S. V. Volkov 《Theoretical and Experimental Chemistry》2008,44(3):139-143
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
16.
《Journal of organometallic chemistry》1987,331(2):263-270
The compound, [η-C5H5Fe(CO)2]2(p-CH3C6H4)SnBr, crystallizes in the monoclinic space group P21/c with a 9.643, b 12.016, c 19.205 Å, β 98.68°, V 2225.9 Å3, and Z = 4. The crystal and molecular structures have been solved by use of the Patterson method. A full-matrix least-squares refinement led to a final R value of 0.036 for 3260 independent observed reflections. The electronic structure was calculated by use of the EHMO quantum chemical method. The molecular features and the influence on the coordinate geometry, and the nature of the bonding of the central tin atom are discussed. 相似文献
17.
Mala Anchal Srivastava Akhilesh K. Pandey Om P. Sengupta Soumitra K. 《Transition Metal Chemistry》2000,25(6):613-616
Bis(cyclopentadienyl)titanium(IV) and zirconium(IV) chlorides react with bis(hydrazones) derived from 1,1-diacetylferrocene in anhydrous THF in the presence of base to give complexes of the type [(Cp2MCl)2L] [M = Ti or Zr; LH2 = ferrocenyl bis(hydrazones)]. Tentative structures are proposed for these complexes based upon elemental analyses, electrical conductance, magnetic moment and spectroscopic data. 相似文献
18.
19.
《Journal of Coordination Chemistry》2012,65(2):71-75
Abstract Crystals of the adduct titanium tetrachloride-ethylcyanoformate (1–1) are monoclinic a =9.06 Å, b =18.36 Å, c =13.83 Å, β =113°.2, space group C2/c, Z =8. The structure was solved by application of X-Ray diffraction techniques at room temperature. Atomic positions were refined by a full-matrix least-squares method to a final R of 0.049 using 829 non-zero independent reflections. This compound is dimeric with a double chlorine bridge between titanium atoms. Titanium is octahedrally coordinated to five chlorine atoms and to the nitrogen atom of the nitrile group and not to the oxygen atom of the carbonyl group. Thus in this complex the nitrogen atom is a better donor than the carbonyl oxygen. 相似文献
20.
N. S. Kopelev Yu. D. Perfiliev Yu. M. Kiselev 《Journal of Radioanalytical and Nuclear Chemistry》1992,162(2):239-251
Sodium ferrates(IV) and (VI) were synthesized by the reaction between Fe2O3 and Na2O2 in a dry oxygen stream. The Mössbauer data for the obtained samples are presented (for Na2FeO3–=0.18(2) mm/s; for Na4FeO5–=–0.54(2) mm/s). It was shown that pure K2FeO4 and Cs2FeO4 can be obtained by heating Fe2O3 with apropriate alkali metal peroxides. 相似文献