共查询到20条相似文献,搜索用时 31 毫秒
1.
The formation of hydrolysed uranyl(VI) species in UO 2X zeolites prepared by various methods has been investigated by Raman spectroscopy. Ion-exchange in aqueous (pH>3) and non-aqueous (anhydrous methanol and uranyl nitrate melts) media resulted in the formation of hydroxy-bridged complexes such as [(UO 2) 3(OH) 4] 2+, [(UO 2) 3(OH) 5] +, and [(UO 2) 4(OH) 7] +. Ion-exchange in more acidic media (initial pH < 3) was accompanied by the formation of a disordered phase incorporating UO 3, following extensive collapse of the zeolite framework structure. Cation speciation in the UO 2X system is compared to that in UO 2Y zeolites. 相似文献
2.
2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol (Br-PADAP) forms a 1:1 complex with the uranyl ion in the presence of sulphosalicylic acid, which acts as stabilizer for this complex in the triethanol amine/perchloric acid buffer system. A change in the stoichiometry of the complex was seen at pH<5. Kinetic measurements were carried out using stopped-flow spectrophotometer in the presence of an excess concentration of U(VI) in the pH range 6.5 to 8. The dependence of the pseudo-first-order rate constant, k(obs), on the concentrations of U(VI), ligand and hydrogen ion showed that Br-PADAP reacts with UO 2(OH) + to form an intermediate species (equilibrium constant = 1.28×10 4mol.dm −3) that then rearranges (rate constant = 5.6×10 −2s −1) to form the product species. UO 2(OH) + is present in equilibrium with the unreactive species UO 2(OH) 2, as well as with the unreactive sulfosalicylic acid complex. 相似文献
3.
A DFT study of U(VI) hydroxy complexes was performed with special attention paid to the [(UO2)3(OH)5(H2O)4–7]+ and [(UO2)4(OH)7(H2O)5–8]+ species. It was established that the ionicity of the U=O bond increased when moving from [(UO2)(H2O)5]2+, [(UO2)2(OH)(H2O)8]3+, [(UO2)2(OH)2(H2O)6]2+, [(UO2)3(OH)5(H2O)4–6]+ to [(UO2)4(OH)7(H2O)5–8]+ species. In both [(UO2)3(OH)5(H2O)4–6]+ and [(UO2)4(OH)7(H2O)5–8]+ complexes, the U=O bond was observed to have a range of different lengths which depended on the composition of the first coordination sphere of UO2
2+. The cyclic structures of trimeric complexes were somewhat more stable than their linear structures, which was probably due to the steric effect. 相似文献
4.
Uranyl–sulphate complexes are the predominant U(VI) species present in acid solutions resulting either from underground uranium
ore leaching or from the remediation of leaching sites. Thus, the study of U(VI) speciation in these solutions is of practical
significance. The spectra of UO 2(NO 3) 2 + Na 2SO 4 solutions of different Φ
S = [SO 42−]/[U(VI)] ratio at pH = 2 were recorded for this purpose. As the presence of uranyl-nitrate complexes should be expected under
these experimental conditions, the spectra of UO 2(NO 3) 2 + NaNO 3 solutions with different Φ
N = [NO 3−]/[U(VI)] ratio at pH = 2 were also measured. The effects of Φ
S and Φ
N ratios value were most pronounced in wavelength interval 380–500 nm. Therefore, these parts of experimental overall spectra
were used for deconvolution into the spectra of individual species by the method proposed. It enabled to calculate stability
constants of anticipated species at zero ionic strength. The Specific Ion Interaction Theory (SIT) was used for this purpose.
Stability constants of UO 2SO 4, UO 2(SO 4) 22−, UO 2NO 3
+ and UO 2(NO 3) 2 coincided well with published data, but those for UO 2(SO 4) 34− and UO 2(NO 3) 3− were significantly lower. 相似文献
5.
A new series of dioxouranium(VI) complexes of a potential ONNO tetradentate donor 2-aminobenzoylhydrazone of butane-2,3-dione
(L 1H 2) have been synthesized. At pH 2·5–4·0, the donor (L 1H 2) reacts in the keto form and complexes of the type [UO 2(L 1H 2)(X) 2] (X −=Cl −, Br −, NO
3
−
, NCS −, ClO
4
−
, CH 3COO −, 1/2SO
4
2−
) are obtained. At higher pH (6·5–7), the complex of the enol form having the formula [UO 2(L 1)(H 2O)] has been isolated. On reaction with a monodentate lewis base (B), both types of complexes yield adducts of the type [UO 2(L 1)(B)]. All these complexes have been characterised adequately by elemental analyses and other standard physicochemical techniques.
Location of the bonding sites of the donor molecule around the uranyl ion, status of the uranium-oxygen bond and the probable
structure of the complexes have also been discussed. 相似文献
6.
The crystal structures of two uranyl nitrate complexes with 2,2′-6,2″-terpyridine ( Trpy), [(UO (Trpy)-[(UO 2) 2(Trpy) 2(OH) 2][UO 2(NO 3) 2(OH) 2] · 2CH 3OH ( I) and [(UO 2) 2(Trpy) 2(OH) 2] 2[UO 2(NO 3) 3(H 2O)](NO 3) 3 · 3H 2O ( II), were studied. Compound I consists of the centrosymmetric dimeric cations [(UO 2) 2(Trpy) 2(OH) 2] 2+, the anions [UO 2(NO 3) 2(OH) 2] 2?, and solvation methanol molecules. Complex II consists of dimeric cations [(UO 2) 2(Trpy) 2(OH) 2] 2+, the complex anions [UO 2(NO 3) 3(H 2O)] ?, nitrate anions, and water molecules of crystallization. The uranium atom in the [UO 2(NO 3) 3(H 2O)] ? anion in II has an unusual coordination polyhedron representing a hexagonal bipyramid in which one oxygen atom in the equatorial plane is replaced by two atoms equidistant from this plane. 相似文献
7.
The following ions [UO 2(NO 3) 3] −, [UO 2(ClO 4) 3] −, [UO 2(CH 3COO) 3] − were generated from respective salts (UO 2(NO 3) 2, UO 2(ClO 4) 3, UO 2(CH3COO)2) by laser desorption/ionization (LDI). Collision induced dissociation of the ions has led, among others, to the
formation of UO 4
− ion ( m/z 302). The undertaken quantum mechanical calculations showed this ion is most likely to possess square planar geometry as
suggested by MP2 results or strongly deformed geometry in between tetrahedral and square planar as indicated by DFT results.
Interestingly, geometrical parameters and analysis of electron density suggest it is an U VI compound, in which oxygen atoms bear unpaired electron and negative charge. 相似文献
8.
Stability data on the formation of dioxouranium(VI) species with polyacrylic (PAA) and fulvic acids (FA) are reported with
the aim to define quantitatively the sequestering capacity of these high molecular weight synthetic and naturally occurring
ligands toward uranium(VI), in aqueous solution. Investigations were carried out at t = 25 °C in NaCl medium at different ionic strengths and in absence of supporting electrolyte for uranyl–fulvate (
\text UO22+ {{\text{UO}}_{2}}^{2+} –FA) and uranyl–polyacrylate (
\text UO 2 2+ {{\text{UO}}_{ 2}}^{ 2+ } –PAA, PAA MW 2 kDa) systems, respectively. The experimental data are consistent with the following speciation models for the
two systems investigated: (i) UO 2(FA 1), UO 2(FA 1)(FA 2), UO 2(FA 1)(FA 2)(H) for
\text UO 2 2+ {{\text{UO}}_{ 2}}^{ 2+ } –fulvate (where FA 1 and FA 2 represent the carboxylic and phenolic fractions, respectively, both present in the structure of FA), and (ii) UO 2(PAA), UO 2(PAA)(OH), (UO 2) 2(PAA)(OH) 2 for
\text UO 2 2+ {{\text{UO}}_{ 2}}^{ 2+ } –polyacrylate. By using the stability data obtained for all the complex species formed, the uranium(VI) sequestration by PAA
and FA was expressed by the pL 50 parameter [i.e. the −log(total ligand concentration) necessary to bind 50% of uranyl ion] at different pH values. A comparison
between pL 50 values of FA and PAA and some low molecular weight carboxylic ligands toward uranyl ion is also given. 相似文献
9.
The formation constants of dioxouranium(VI)-2,2′-oxydiacetic acid (diglycolic acid, ODA) and 3,6,9-trioxaundecanedioic acid
(diethylenetrioxydiacetic acid, TODA) complexes were determined in NaCl (0.1≤ I≤1.0 mol⋅L −1) and KNO 3 ( I=0.1 mol⋅L −1) aqueous solutions at T=298.15 K by ISE-[H +] glass electrode potentiometry and visible spectrophotometry. Quite different speciation models were obtained for the systems
investigated, namely: ML 0, MLOH −, ML 22−, M 2L 2(OH) −, and M 2L 2(OH) 22−, for the dioxouranium(VI)–ODA system, and ML 0, MLH +, and MLOH − for the dioxouranium(VI)–TODA system (M=UO 22+ and L = ODA or TODA), respectively. The dependence on ionic strength of the protonation constants of ODA and TODA and of
both metal-ligand complexes was investigated using the SIT (Specific Ion Interaction Theory) approach. Formation constants
at infinite dilution are [for the generic equilibrium pUO 22++ q(L 2−)+ rH +
⇌(UO 22+)
p
(L)
q
H
r
(2p−2q+r); β
pqr
]: log 10
β
110=6.146, log 10
β
11−1=0.196, log 10
β
120=8.360, log 10
β
22−1=8.966, log 10
β
22−2=3.529, for the dioxouranium(VI)–ODA system and log β
110=3.636, log 10
β
111=6.650, log 10
β
11−1=−1.242 for dioxouranium(VI)–TODA system. The influence of etheric oxygen(s) on the interaction towards the metal ion was
discussed, and this effect was quantified by means of a sigmoid Boltzman type equation that allows definition of a quantitative
parameter (p L
50) that expresses the sequestering capacity of ODA and TODA towards UO 22+; a comparison with other dicarboxylates was made. A visible absorption spectrum for each complex reaching a significant percentage
of formation in solution (KNO 3 medium) has been calculated to better characterize the compounds found by pH-metric refinement. 相似文献
10.
The new U(VI) compound, [Ni(H 2O) 4] 3[U(OH,H 2O)(UO 2) 8O 12(OH) 3], was synthesized by mild hydrothermal reaction of uranyl and nickel nitrates. The crystal-structure was solved in the P-1 space group, a=8.627(2), b=10.566(2), c=12.091(4) Å and α=110.59(1), β=102.96(2), γ=105.50(1)°, R=0.0539 and w R=0.0464 from 3441 unique observed reflections and 151 parameters. The structure of the title compound is built from sheets of uranium polyhedra closely related to that in β-U 3O 8. Within the sheets [(UO 2)(OH)O 4] pentagonal bipyramids share equatorial edges to form chains, which are cross-linked by [(UO 2)O 4] and [UO 4(H 2O)(OH)] square bipyramids and through hydroxyl groups shared between [(UO 2)(OH)O 4] pentagonal bipyramids. The sheets are pillared by sharing the apical oxygen atoms of the [(UO 2)(OH)O 4] pentagonal bipyramids with the oxygen atoms of [NiO 2(H 2O) 4] octahedral units. That builds a three-dimensional framework with water molecules pointing towards the channels. On heating [Ni(H 2O) 4] 3[U(OH,H 2O)(UO 2) 8O 12(OH) 3] decomposes into NiU 3O 10. 相似文献
11.
Base hydrolysis of [Cr(ox) 2(quin)] 3− (where quin 2− is N,O-bonded 2,3-pyridinedicarboxylic acid dianion) causes successive ligand dissociation and leads to a formation of a
mixture of oligomeric chromium(III) species, known as chromates(III). The reaction proceeds through [Cr(ox)(quin)(OH) 2] 3− and [Cr(quin)(OH) 4] 3− formation. Dissociation of oxalato ligands is preceded by the opening of the Cr-quin chelate-ring at the Cr–N bond. The kinetics
of the chelate-ring opening and the first oxalate dissociation were studied spectrophotometrically, within the lower energy
d–d band region at 0.4–1.0 M NaOH. The pseudo-first-order rate constants ( k
obs0 and k
obs1) were calculated using SPECFIT software for an A → B → C reaction pattern. Additionally, kinetics of base hydrolysis of [Cr(ox)(quin)(OH) 2] 3− and cis-[Cr(ox) 2(OH) 2] 3− were studied. The determined pseudo-first-order rate constants were independent of [OH −]. A mechanism is postulated that the reactive intermediate with the one-end bonded quin ligand, [Cr(ox) 2(O-quin)(OH)] 4−, formed in the first reaction stage, subsequently undergoes oxalates substitution. Kinetic parameters for the chelate-ring
opening and the first oxalate dissociation were determined. 相似文献
12.
New complexes of MoO 2(VI), WO 2(VI), Th(IV) and UO 2(VI) with aroyl hydrazones have been prepared and characterized by various physicochemical methods. Elemental analysis suggested
1 : 1 metal : ligand stoichiometry for MoO 2(VI), WO 2(VI), and UO 2(VI) complexes whereas 1 : 2 for Th(VI) complexes. The physicochemical studies showed that MoO 2(VI), Th(IV) and UO 2(VI) complexes are octahedral. The electrical conductivity of these complexes lies in the range 1.00 × 10 −7−3.37 × 10 −11Ω −1 cm −1 at 373 K. The complexes were found to be quite stable and decomposition of the complexes ended with respective metal oxide
as a final product. The thermal dehydration and decomposition of these complexes were studied kinetically using both Coats-Redfern
and Horowitz-Metzger methods. It was found that the thermal decomposition of the complexes follow first order kinetics. The
thermodynamic parameters of the decomposition are also reported. The biological activities of ligands and their metal complexes
were tested against various microorganisms. 相似文献
13.
In order to analyze the formation of hetero-metal polynuclear hydrolytic species, in this paper, we reported some results of an investigation (at I = 0.16 mol L −1 in NaNO 3, at t = 25 °C by potentiometry, ISE-H +, glass electrode) on the hydrolysis of several mixtures (in different ratios) of two couples of cations: dioxouranium(VI)/copper(II) and dioxouranium(VI)/diethyltin(IV). The elevated total concentrations of cations 0.005 ≤ Σ CM mol L −1 ≤ 0.05) adopted in these measurements induced us to study again the hydrolysis of uranyl, for which no suitable literature data are available in these particular experimental conditions. All measurements were performed by two different operators, using completely independent instruments and reagents. Many different speciation models were considered in the calculations, including the simultaneous refinement of homo- and hetero-metal species, and a statistical analysis of obtained results was proposed too. Main results can be summarized as follows: UO 22+ and Cu 2+ form three hetero-metal polynuclear hydrolytic species [(UO 2)Cu(OH) 3+, (UO 2)Cu 2(OH) 2+ and (UO 2) 2Cu 4(OH) 2+, with log βpqr = −2.93 ± 0.01, −7.34 ± 0.03 and −13.78 ± 0.03, respectively], all those common to their simple speciation without the other cation; UO 22+ and (C 2H 5) 2Sn 2+ form seven mixed hydrolytic species [(UO 2)(DET)(OH) 3+, (UO 2)(DET) 2(OH) 2+, (UO 2) 2(DET) 4(OH) 2+, (UO 2)(DET) 24(OH) 2+, (UO 2) 2(DET) +5(OH), (UO 2)(DET) 2+5(OH) and (UO 2) 2(DET) −7(OH), with log βpqr = −2.5 ± 0.2, −4.74 ± 0.02, −10.70 ± 0.06, −10.34 ± 0.03, −15.70 ± 0.06, −15.58 ± 0.06 and −27.9 ± 0.1, respectively] that are of the same kind of those formed by uranyl; formation of mixed hydrolytic species causes a significant enhancement of the percentage of hydrolyzed metal cations, modifying the solubility and, therefore, the bioavailability of these cations. We also determined, for dioxouranium(VI)/copper(II) system, the corresponding complex formation enthalpies and entropies by direct calorimetric measurements. We obtained Δ H112 = 47.9 ± 0.6 and Δ H214 = 92.9 ± 0.5 kJ mol −1, TΔ S112 = 6 ± 1 and TΔ S214 = 14 ± 1 kJ mol −1 (±S.D.), respectively, for the formation of (UO 2)(Cu) 2(OH) 2+ and (UO 2) 2(Cu) 4(OH) 2+ species (according to reaction 2). We also calculated the single enthalpic and entropic contributes to the extra-stability that these species show with respect to the corresponding homo polynuclear ones. 相似文献
14.
The interaction of uranium(VI) with carbonate ions was studied with absorption spectroscopy and time-resolved laser-induced
fluorescence spectroscopy due to the importance of these complexes in environmental relevant waters. In the pH range from
2 to 11 the influence of the temperature on the spectra was studied to check changes in the abundances of several binding
forms. It was found that several binding forms are predominant at different temperatures and pH values. This observation can
be explained by speciation changes due to the dependence of chemical equilibria on the temperature. Furthermore photoluminescence
spectra of aqueous solutions of uranyl carbonate complexes were observed at ambient temperatures for the first time and single
component absorption spectra of the uranyl carbonate complexes UO 2(CO 3) 3
4− and UO 2(CO 3) 2
2− were derived. 相似文献
15.
Potentiometric titrations of uranyl(VI) solutions were conducted using a standard glasslcalomel electrode combination over the pH range 3 to 12 at 0.1 molkg –1 ionic strength with tetramethylammonium trifluoromethanesulfonate as the supporting electrolyte. The electrodes were calibrated directly on the hydrogen ion concentration scale during the initial stage of each titration. The species, UO
2
2+
, (UO 2) 2(OH)
2
2+
, (UO 2) 3(OH)
5
+
, (UO 2) 3(OH)
7
–
, (UO 2) 3(OH)
8
2–
, and (UO 2) 3(OH)
10
4–
identified in an earlier Raman study were compatible with the analysis of the titration data. Based on this analysis and application of the extended Debye-Hückel treatment, the polynuclear species indicated above were assigned overall formation constants at 25°C and at infinite dilution of –5.51±0.04, –15.3±0.1, –27.77±0.09, –37.65±0.14, and –62.4±0.3, respectively. The results are discussed in reference to hydrolysis quotients reported in the literature for the first three species. Formation quotients for the last two species have not been reported previously. 相似文献
16.
Two solid complexes, fac–[Cr(gly) 3] and [Cr(gly) 2(OH)] 2, (where gly is glycinato ligand) were prepared and their acid-catalysed aquation products were identified. The structure
of [Cr(gly) 3] was solved by X-ray diffraction, revealing a cationic 3D sublattice with perchlorate anions inside its cavities. Acid-catalysed
aquation of [Cr(gly) 3] and [Cr(gly) 2(OH)] 2 leads to the same inert product, [Cr(gly) 2(H 2O) 2] +, in a two-stages process. At the first stage, intermediate complexes, [Cr(gly) 2(O–glyH)(H 2O)] + and [Cr(gly) 2(H 2O)–OH–Cr(gly) 2(H 2O)] +, are formed respectively. Kinetics of the first aquation stage of [Cr(gly) 3] were studied in HClO 4 solutions. The dependencies of the pseudo first-order rate constants on [H +] are as follows: k
obs1H = k
0 + k
1
K
p1[H +], where k
0 and k
1 are rate constants for the chelate-ring opening via spontaneous and acid-catalysed reaction paths, respectively, and K
p1 is the protonation constant. The proposed mechanism assumes formation of the reactive intermediate as a result of proton
addition to the coordinated carboxylate group of the didentate ligand. Some kinetic studies on the second reaction stage,
the one-end bonded glycine liberation, were also done. The obtained results were analogous to those for stage I. In this case,
the proposed reactive species are intermediates, protonated at the carboxylate group of the monodentate glycine. Base hydrolysis
of two complexes, [Cr(gly) 2(O–gly)(OH)] − and [Cr(gly) 2(OH) 2] −, was studied in 0.2–1.0 M NaOH. The pseudo first-order rate constants, k
obsOH, were [OH −] independent in the case of [Cr(gly) 2(O–gly)(OH)] −, whereas those for [Cr(gly) 2(OH) 2] − linearly depended on [OH −]. The reaction mechanisms were proposed, where the OH − -catalysed reaction path was rationalized in terms of formation of the reactive conjugate base, [Cr(gly) 2(OH)(O)] 2−, as a result of OH − ligand deprotonation. Activation parameters were determined and discussed. 相似文献
17.
The complex species formed between vanadium(III)?C2,2??-bipyridine (Bipy) and the small blood serum bioligands lactic (HLac), oxalic (H 2Ox), citric (H 3Cit) and phosphoric (H 3PO 4) acids were studied in aqueous solution by means of electromotive forces measurements emf(H) at 25?°C and 3.0?mol?dm ?3 KCl as the ionic medium. The data were analyzed using the least-squares computational program LETAGROP, taking into account the hydrolytic products of vanadium(III) and the binary complexes formed. Formation of the complexes [V(Bipy)(Lac)] 2+, [V(Bipy)(Lac) 2] +, [V(OH) 2(Bipy)(Lac)] and [V 2O(Bipy) 2(Lac) 2] ? were observed in the vanadium(III)?CBipy?CHLac system. Also, the species [V(Bipy)(HOx)] 2+, [V(Bipy)(Ox)] +, [V(OH)(Bipy)(Ox)], [V(OH) 2(Bipy)(Ox)] ? and [V(OH) 3(Bipy)(Ox)] 2? were found in the vanadium(III)?CBipy?CH 2Ox system, the complexes [V(Bipy)(HCit)] +, [V(Bipy)(Cit)], [V(OH)(Bipy)(Cit)] ? and [V(OH) 2(Bipy)(Cit)] 2? were found in the vanadium(III)?CBipy?CH 3Cit system, and the species [V(Bipy)(H 2PO 4)] 2+ and [V(Bipy)(HPO 4)] + were detected in the vanadium(III)?CBipy?CH 3PO 4 system. The stability constants of these complexes were determined. 相似文献
18.
Chromium(III)-carbonate reactions are expected to be important in managing high-level radioactive wastes. Extensive studies
on the solubility of amorphous Cr(III) hydroxide solid in a wide range of pH (3–13) at two different fixed partial pressures
of CO 2(g) (0.003 or 0.03 atm.), and as functions of K 2CO 3 concentrations (0.01 to 5.8 mol⋅kg −1) in the presence of 0.01 mol⋅dm −3 KOH and KHCO 3 concentrations (0.001 to 0.826 mol⋅kg −1) at room temperature (22±2 °C) were carried out to obtain reliable thermodynamic data for important Cr(III)-carbonate reactions.
A combination of techniques (XRD, XANES, EXAFS, UV-Vis-NIR spectroscopy, thermodynamic analyses of solubility data, and quantum
mechanical calculations) was used to characterize the solid and aqueous species. The Pitzer ion-interaction approach was used
to interpret the solubility data. Only two aqueous species [Cr(OH)(CO 3) 22− and Cr(OH) 4CO 33−] are required to explain Cr(III)-carbonate reactions in a wide range of pH, CO 2(g) partial pressures, and bicarbonate and carbonate concentrations. Calculations based on density functional theory support
the existence of these species. The log 10
K° values of reactions involving these species [{Cr(OH) 3(am) + 2CO 2(g) ⇌Cr(OH)(CO 3) 22−+2H +} and {Cr(OH) 3(am) + OH −+CO 32−
⇌Cr(OH) 4CO 33−}] were found to be −(19.07±0.41) and −(4.19±0.19), respectively. No other data on any Cr(III)-carbonato complexes are available
for comparisons. 相似文献
19.
Group V Nb-polyoxometalate (Nb-POM) chemistry generally lacks the elegant pH-controlled speciation exhibited by group VI (Mo, W) POM chemistry. Here three Nb-POM clusters were isolated and structurally characterized; [Nb 14O 40(O 2) 2H 3] 14−, [((UO 2)(H 2O)) 3Nb 46(UO 2) 2O 136H 8(H 2O) 4] 24−, and [(Nb 7O 22H 2) 4(UO 2) 7(H 2O) 6] 22−, that effectively capture the aqueous Nb-POM species from pH 7 to pH 10. These Nb-POMs illustrate a reaction pathway for control over speciation that is driven by counter-cations (Li +) rather than pH. The two reported heterometallic POMs (with UO 22+ moieties) are stabilized by replacing labile H 2O/HO−Nb=O with very stable O=U=O. The third isolated Nb-POM features cis-yl-oxos, prior observed only in group VI POM chemistry. Moreover, with these actinide-heterometal contributions to the burgeoning Nb-POM family, it now transects all major metal groups of the periodic table. 相似文献
20.
The metathesis reaction of the magnesium complex [(dpp-BIAN) 2−Mg 2+(THF) 3] (dpp-BIAN is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with one equivalent of AlCl 3 in toluene gave the [(dpp-BIAN) 2−AlCl 2] −[Mg 2Cl 3(THF) 6] + complex ( 1). Reduction of dpp-BIAN with aluminum metal in the presence of AlCl 3 and AlI 3 in toluene and diethyl ether afforded the radical-anionic complex [(dpp-BIAN) −AlCl 2] ( 2) and the dianionic complexes [(dpp-BIAN) 2−AlI(Et 2O)] ( 3) and [(dpp-BIAN) 2−AlCl(Et 2O)] ( 4), respectively. Compounds 1–4 were isolated in the crystalline state and characterized by IR spectroscopy and elemental analysis. The structures of compounds
1–3 were established by X-ray diffraction. Compound 2 was characterized by ESR spectroscopy. Compounds 3 and 4 were studied by 1H and 13C NMR spectroscopy.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 409–415, March, 2006. 相似文献
|