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1.
Ultrasensitive chemiluminescence (CL) detection of aM vanadium(IV) in capillary electrophoresis (CE) is first reported. In this work, inclusion of the luminol in the electrophoretic carrier electrolyte avoids the loss of light signal that occurs when luminol and hydrogen peroxide are mixed in advance, as in the conventional method in CE-CL detection. The detection limit (S/N ratio=3) for V(IV) is 2.4×10−17 M (24 aM), which has been improved by a factor of 104 as compared with that of the most sensitive metal ion detection (Co2+ 0.5 pM) reported previously. In addition, the separation of V(IV) and V(V) has been performed successfully. 相似文献
2.
E. Ludwig H. Hefele A. Friedrich B. Kallies U. Schilde E. Uhlemann E. Hahn 《无机化学与普通化学杂志》1995,621(3):488-494
Reactions and Thermal Behaviour of Nonoxo Vanadium(IV) Complexes. Crystal Structures of Methoxo-oxo[thenoyltrifluoroacetone-salicylhydrazonato(2–)]vanadium(V) and Methoxo-oxo[benzoylacetone-salicylhydrazonato(2–)]vanadium(V) The persistence of non-oxo vanadium(IV) complexes in dichlormethane/methanol/water solutions was studied by UV/VIS spectroscopy. The reaction products methoxo-oxo-[thenoyltrifluoroacetone-salicylhydrazonato(2–)]vanadium(V) and methoxo-oxo[benzoylacetone-salicylhydrazonato(2–)]vanadium(V) were isolated and characterized by X-ray analysis. The thermal behaviour of non-oxo vanadium(IV) complexes was checked. 相似文献
3.
Roberto Gazzi Francesca Perazzolo Arlen Ferrari 《Journal of organometallic chemistry》2005,690(8):2071-2077
The electronic features and photochemistry of TpTiCl3 (1) (Tp = hydrotris(pyrazol-1-yl)borate) and Tp*TiCl3 (2) (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) were studied in THF. Reactive decay of the excited states produced either (or ) and metal center Ti(III) radicals via homolytic cleavage of the Tp → Ti (Tp* → Ti) bond. Cleavage of the Tp → Ti and the Tp* → Ti bond as a primary photoprocess is shown to be consistent with LMCT Tp → Ti and Tp* → Ti excitation. TpTiCl2(THF) (3) and Tp*TiCl2(THF) (4) were also prepared by stoichiometric reduction of 1 and 2 with Li3N. The THF ligand in 3 and 4 was replaced by the stable nitroxyl radical TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) to provide the new complexes TpTiCl2(TEMPO) (5) and Tp*TiCl2(TEMPO) (6) in which the TEMPO ligand is η1 coordinated to Ti(IV). Photolysis of 5 and 6 generate Ti(III) and the TEMPO radical in the primary photochemical step. 相似文献
4.
E. G. Ferrer S. B. Etcheverry E. J. Baran 《Monatshefte für Chemie / Chemical Monthly》1993,124(4):355-366
Summary The synthesis of a new vanadyl(IV)/saccharin complex is reported. Its bonding characteristics differ considerably from all known divalent metal-saccharinates. In this complex a VO(OH)+ moiety is coordinated to a saccharin molecule through its carbonyl oxygen and to a saccharinate ion through its deprotonated nitrogen. Two water molecules complete the coordination sphere. X-ray powder diagrams, infrared- and electronic absorption-spectra were recorded and analyzed for the characterization of the compound and its coordination properties. Besides, the magnetic susceptibility and the thermal behaviour were also investigated. 相似文献
5.
Petr Novk Zdeka Padlkov Ivana Císaov Lenka Kolov Ale Ri
ka Jaroslav Hole
ek 《应用有机金属化学》2006,20(3):226-232
Three monoorganotin(IV) compounds of general formula LCNSnX3, where LCN is a 2‐(dimethylaminomethyl)phenyl‐ group and X = Cl ( 1 ), Br ( 2 ) and I ( 3 ), were prepared and characterized using XRD and NMR techniques. Compound 1 reacts with moisture producing [(LCN)2HSnCl2]+ [LCNSnCl4]?. Compound 3 decomposes to (LCN)2SnI2, SnI2 and I2 when heated. Compound 2 was reacted with NH4F yielding an equilibrium of fluorine‐containing species. The major products were [LCNSnF5]2? and [(LCNSnF3)2(µ2‐F)2]2? (4a). When compound 2 was reacted with another fluorinating agent, LCN(n‐Bu)2SnF, an oligomeric product, [LCNSnF2(µ2‐F)2]n, was observed. Further addition of NH4F led to subsequent formation of 4a. The structure of fluorinated products was investigated by 1H, 19F and 119Sn NMR spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
6.
Molecular Structure of Bis[salicylaldehyde-2-hydroxyanilato(2—)]vanadium(IV) By the reaction of tris(acetylacetonato)vanadium(III) with salicylaldehyde-2-hydroxyanil the non-oxo vanadium(IV) complex of this ligand was prepared. Bis[salicylaldehyde-2-hydroxyanilato(2—)]vanadium(IV) has a distorted octahedral structure. Crystallographic data see “Inhaltsübersicht”. 相似文献
7.
Diorganotin(IV) and diorganosilicon(IV) derivatives of the types R2MCl(TSCZ) and R2M(TSCZ)2 (where TSCZ is the anion of a thiosemicarbazone ligand, R=Ph or Me and M=Sn or Si) have been synthesized and characterized by elemental analyses, molecular weight determinations and conductivity measurements. The mode of bonding has been established on the basis of IR and 1H, 13C 29Si and 119Sn NMR spectroscopic studies. Some of the representative complexes have also been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria in vivoas well as in vitro.The results of these investigations are reported. © 1998 John Wiley & Sons, Ltd. 相似文献
8.
9.
The complex [VO(MPO)2] (MPO = deprotonated 2‐mercaptopyridine N‐oxide) was synthesized and characterized by IR spectroscopy. Its electrochemical behaviour was investigated by cyclic voltammetry in different organic solvents. The VIV/VV and VIV/VIII couples could be identified. The nature of the electroactive species is strongly dependent on the solvent. The results are discussed in terms of a reaction mechanism describing the characteristics of the electron transfer processes and the involved chemical reactions, and the stability of the complex in each solvent was also determined. The electronic spectra of the investigated solutions gave additional support to the proposed mechanisms. 相似文献
10.
The metal anions of vanadium (V) and chromium (VI) in aqueous solution can be effectively adsorbed by Zr(IV)-impregnated collagen
fiber (ZrICF). The maximum adsorption capacity of V(V) takes place within the pH range of 5.0 to 8.0, while that of Cr(VI)
is within the pH range of 6.0 to 9.0. When the initial concentration of metal ions was 2.00 mmol L−1 and the temperature was 303 K, the adsorption capacity of V(V) on Zr-ICF was 1.92 mmol g−1 at pH 5.0, and the adsorption capacity of Cr(VI) was 0.53 mmol g−1 at pH 7.0. As temperature increased, the adsorption capacity of V(V) increased, while that of Cr(VI) was almost unchanged.
The adsorption isotherms of the anionic species of V(V) and Cr(VI) can be fit by the Langmuir equation. The adsorption rate
of V(V) follows the pseudo-first-order rate model, while the adsorption rate of Cr(VI) follows the pseudo-second-order rate
model. Furthermore, ZrICF shows high adsorption selectivity to V(V) in the mixture solution of V(V) and Cr(VI). Practical
applications of ZrICF could be expected in consideration of its performance in adsorption of V(V) and Cr(VI). 相似文献
11.
L. T. Vlaev V. G. Georgieva S. D. Genieva 《Journal of Thermal Analysis and Calorimetry》2007,88(3):805-812
The kinetics of dehydration and decomposition of VOSO4·2H2O, VOSO4 and VOSeO3·H2O was studied under non-isothermal heating on a derivatograph. The stages and products of the thermal decomposition were determined.
It was proved that VOSO4·2H2O decomposes to V2O5 while VOSeO3·H2O − to V2O4. A number of kinetic models and calculation procedures were used to determine the values of the kinetic parameters characterizing
the process. The parameters calculated were compared and analyzed. IR-spectra of the initial substances and the solid residue
after decomposition are presented. 相似文献
12.
Paula C. dos Santos Claro Ana C. Gonzlez‐Bar Beatriz S. Parajn‐Costa Enrique J. Baran 《无机化学与普通化学杂志》2005,631(10):1903-1908
The infrared, Raman and electronic spectra of the oxovanadium (IV) complexes of the 3‐methyl and 3‐ethyl substituted acetylacetone were recorded and discussed in detail, in comparison with that of the bis(acetylacetonato) complex and on the basis of the known structural data of these compounds. The electrochemical behavior of the three complexes was investigated by cyclic voltammetry in DMSO solutions, and the mechanism of the involved processes is briefly discussed. 相似文献
13.
Non-oxo Vanadium(IV) Complexes with Tridentate Diacidic Ligands. Molecular Structure of Bis[2.2′-dihydroxy-azobenzenato(2?)]vanadium(IV) By the reaction of tris(acetylacetonato)vanadium(III) with tridentate diacidic ligands non-oxo vanadium(IV) complexes of these ligands were synthesized. The complexes were characterized by mass spectrometry. Electrochemical studies show that the complexes are reversibly oxidized or reduced. Bis[2,2′-dihydroxy-azobenzenato(2?)]vanadium(IV) has a distorted trigonal-prismatic structure. Crystallographic data see ?Inhaltsübersicht”?. 相似文献
14.
Preparation and Spectroscopic Characterization of Bond Isomeric Halogenoselenocyanato-Osmates(IV) and -Rhenates(IV) By oxidative ligand exchange of appropriate chloro-iodo complexes of OsIV or ReIV with (SeCN)2 in CH2Cl2 or by heterogeneous reaction with Pb(SeCN)2 or AgSeCN in CH2Cl2 the new complexes cis-[OsCl4(NCSe)(SeCN)]2?, tr.-[OsCl4Br(NCSe)]2?, tr.-[OsCl4Br(SeCN)]2?, [ReCl5(NCSe)]2?, [ReCl5(SeCN)]2?, tr.-[ReCl4I(NCSe)]2?, tr.?[ReCl4(NCSe)(SeCN)]2? and tr.?[ReCl4(NCSe)2]2? are formed and isolated as pure compounds by ion exchange chromatography on DEAE-cellulose. The bond isomers are significantly distinguished by the frequencies of innerligand vibrations: n?CN(Se) > n?CN(N); n?CSe(N) > n?CSe(Se); δNCSe > δSeCN. The electronic spectra (10 K) of the solid salts reveal a bathochromic shift for the charge transfer bands of the Se isomers as compared with the corresponding N isomers. The intra-configurational transitions are observed for the OsIV complexes at 600 to 2400 and for the ReIV complexes at 500 to 1600 nm. The 77Se nmr signals of the OsIV bond isomers are registrated for Se binding in the region 970 to 1040 ppm, for N coordination downfield at 1540 to 1640 ppm. 相似文献
15.
C. D. Habben 《无机化学与普通化学杂志》1991,606(1):229-232
Synthesis of Boron-Sulfur(IV)-Nitrogen Heterocycles The reaction of bis(lithio.tert.-butylamino)phenylborane with tert.-butyldichlorosulfimide and bischlorodimethylsilylsulfodiimide respectively leads to four- or eight-membered heterocycles. The disulfanebridge of one dithiazadiborolidine can be replaced by the ? N?S?N-sequence to yield a Thiatriazadiborine. 1H, 11B, 13C-NMR, mass spectra, and analytical data are reported and discussed. 相似文献
16.
《Magnetic resonance in chemistry : MRC》2002,40(4):289-292
The 17O NMR spectra of 17O isotope‐enriched tributyltin(IV) acetate (1) and dibutyltin(IV) diacetate (2) were recorded in various solvents over wide temperature ranges. Only a single 17O signal was observed for both oxygen atoms of the —COOSn—groups under these experimental conditions, in both non‐coordinating and coordinating solvents. The 17O NMR spectra of tert‐butyl acetate (3) were obtained for comparison. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
17.
In order to correlate 119Sn Mössbauer parameters and structural data for dimethyltin(IV) derivatives, the molecular structures of bis(acetato)dimethyltin(IV) and bis(trifluoroacetato)dimethyltin(IV) were determined by single crystal X-ray diffration. Crystals of Me2Sn(OOCCH3)2 are monoclinic, a = 26.282(4), b = 5.282(1), c = 14.434(3) Å, β = 101.17(2)°, Z = 8, space group C2/c, and those of [Me2Sn(OOCCF3)2]n are monoclinic, a = 8.444(1), b = 17.689(1), c = 15.368(1) Å, β = 93.013(9)°, Z = 8, space group Cc. The structures were solved by the Patterson method and were refined by full-matrix least-squares procedures to R = 0.025 and 0.027 (Rw = 0.023 and 0.030) for 2 298 and 4 182 reflections with I ≥ 3σ(F2), respectively. 相似文献
18.
Basudeb Saha Sumana Gangopadhyay Mahammad Ali Pradyot Banerjee 《Journal of Chemical Sciences》1995,107(4):393-402
The kinetics of the reduction of [NiIII(L1)]2+ (where HL1 = 15-amino-3-methyl-4,7,10,13-tetraazapentadec-3-en-2-one oxime) by sulphur(IV) and selenium (IV) over the regions pH 2.50–8.02
and 2.01–4.00 respectively have been investigated at 30°C. Attempts were made to evaluate the reactivity of all the reacting
species, of sulphur(IV) and selenium(IV) by considering suitable pH ranges. The oxidation of SC2·H2O and HSO
3
−
is proposed to proceed through the formation of a hydrogen-bonded adduct. The reaction with SO
3
2−
seems to follow a direct outer-sphere route which is well supported by Marcus crossrelation calculation. The oxidation of
HSeO
l3
−
is ≈ 103 times slower than that of H2SeO3. The kinetic data indicate that the oxidation of sulphur(IV) by [NiIIIL1)]2+ is much more favourable as compared to the corresponding oxidation of selenium(IV). 相似文献
19.
Gholamhossein Grivani Aliakbar Dehno KhalajiVida Tahmasebi Kazuma GotohHiroyuki Ishida 《Polyhedron》2012,31(1):265-271
The Schiff base ligand N-salicylidin-2-bromoethylimine (L) and its vanadium(IV) complex, VOL2 (1), were synthesized and characterized by using X-ray, CHN, 1H NMR and FT-IR methods. X-ray analysis shows the Schiff base ligand L acts as a bidentate (O, N) chelating ligand and coordinates via imine nitrogen and phenolato oxygen atoms to the V(IV) center. The coordination geometry around the V(IV) center in 1 is approximately square pyramidal, as indicated by the unequal metal-ligand bond distances and angles, with the basal plane formed by the N2O2 donors of the two bidentate Schiff base ligands, the two phenolato O atoms and the two imine N atoms are in the trans position. The coordination sphere of the V(IV) is completed by one oxygen atom in apical position. In the Schiff base ligand, L, there are some classical intramolecular O1-H1?N1 and non-classical intermolecular C9-H9b?O1 hydrogen bonds, while in 1, there are two non-classical intermolecular C7-H7?O3 and C8-H8b?O3 hydrogen bonds. The catalytic activity of 1 in epoxidation of cyclooctene was investigated in different conditions to obtain optimum conditions. The effects of solvent, oxidant, catalyst concentration and alkene/oxidant ratio were studied and the results showed that in CCl4 in the presence of tert-butylhydroperoxide in 1:3 alkene/oxidant ratio, high epoxide yield was obtained. The epoxidation of alkenes was also carried out in optimized conditions that high catalytic activity and selectivity were obtained. 相似文献
20.
Summary Six VO2+ complexes of 8-hydroxyquinoline (oxine) and of some of its mono- and dihalogenated derivatives have been prepared. The complex of 5-chloro-oxine is very unstable and oxidizes rapidly, generating a V(V) complex of stoichiometry VO(QCl)2OH which could also be prepared in pure form. The infrared spectra of all complexes have been recorded and are discussed in detail. The complexes containing halogenated ligands appear as polymeric species, interacting through V=O...V=O bridges. The magnetic moments, investigated at room temperature, indicate completely quenched orbital contributions. The analysis of the electronic spectra reveals very complex solution behaviour including, oxidation phenomena, ligand loss, and interaction with the solvent.
Oxovanadium(IV)-Komplexe von halogenierten Oxinen
Zusammenfassung Sechs VO2+-Komplexe von 8-Hydroxyquinolin (Oxin) und einige seiner mono- und dihalogenierten Derivate wurden dargestellt. Der Komplex des 5-Chloroxins erwies sich als besonders instabil und oxidiert sehr schnell unter Bildung eines V(V)-Komplexes der Stöchiometrie VO(QCl)2OH, welcher auch in reiner Form dargestellt werden konnte. Die Infrarotspektren aller Komplexe wurden aufgenommen und werden eingehend diskutiert. Die Komplexe mit halogenierten Liganden erscheinen als polymere Spezies, welche über V=O...V=O-Brücken wechselwirken. Die bei Raumtemperatur gemessenen magnetischen Momente zeigen die totale Abwesenheit von Orbitalbeiträgen. Die Analyse der Elektronenspektren weist auf ein besonders kompliziertes Lösungsverhalten hin, welches Oxidationsphänomene, Ligandenabspaltung und Wechselwirkung mit den Lösungsmitteln einschließt.相似文献