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1.
The reaction of the tetranuclear trimethylacetate complex Co4(3-OH)2(-OOCCMe3)4(2-OOCCMe3)2(EtOH)6 with pyridine in acetonitrile was studied. Two new compounds, viz., the hexanuclear cobalt(ii) complex Co6py4(3-OH)2(-OOCCMe3)10 (25% yield) and the unusual ionic compound [Co3py3(3-O)(-OOCCMe3)6]+[Co4py(4-O)(-OOCCMe3)7] (5% yield), were prepared. The structures of the new compounds were established by X-ray diffraction analysis.  相似文献   

2.
The oxidation of cumene and a cumene-nitrobenzene (12) mixture at 60°C in the presence of AIBN and acetylacetonates of Co(II), Cu(II), Fe(II), Fe(III), V(III), Cr(III), Mn(III) and MoO 2 2+ has been investigated.
(12) 60°C - Co(II), Cu(II), Fe(II), Fe(III), V(III), Cr(III), Mn(III), MoO 2 +2 .
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3.
Addition of aqueous HCl to Ru5( 3-C=CH2)(-SMe)2(-PPh2)2(CO)10 afforded the structurally characterized carbyne complex Ru5( 3-SMe)( 3-CMe)(-Cl)(-SMe)(-PPh2)2(CO)9, formed by addition of H to the vinylidene ligand; a Cl atom bridges an Ru–Ru bond.  相似文献   

4.
Summary A rapid ion-exchange method for the determination of 144Ce, 137Cs, 89Sr, 90Sr and 140Ba in 2–30 liter samples of atmospheric water precipitations is described. The samples, containing up to 300 mg of calcium, are sorbed on a specially shaped column filled with Dowex 50, X-8 or Dowex 50W, X-8. Radio-cerium and radio-caesium are stripped from the column with 0.6 M ammonium glycolate/ 0.2 M NaCl, pH 5, radio-strontium and radio-barium with 0.15 M ammonium citrate, pH 7.5. The isolated radio-nuclides are counted on a low-background beta-counter: 144Ce as CeO2, 137Cs as Cs-dipicrylaminate, 89Sr/90Sr as SrCO3, 90Y as Y2O3, and 140Ba as BaCO3. The mean chemical yields amount to 95% for cerium, 85% for caesium, 95% for strontium, 95% for yttrium and 65% for barium. With parallel determinations at levels of a few picocuries, the deviations of the results from the respective mean values generally do not exceed ± 5%. With a 30 l sample the limit of detection amounts to 0.005 Ci/l for 144Ce, 0.006 Ci/l for 137Cs, 0.005 Ci/l for 90Sr, and 0.006 Ci/l for 140Ba.
Zusammenfassung Es wird eine schnelle Ionenaustauschmethode für die Bestimmung von 144Ce, 137Cs, 89Sr, 90Sr und 140Ba in 2–30 l Proben von atmosphärischen Wasser-Niederschlägen beschrieben. Die Proben, mit einem Calciumgehalt bis zu 300 mg, werden in eine besonders gestaltete, mit Dowex 50, X-8 oder Dowex 50 W, X-8 gefüllte Säule eingewaschen. Radio-Cer und Radio-Caesium werden mit 0,6 M Ammoniumglykolat/0,2 M NaCl, pH 5, Radio-Strontium und Radio-Barium mit 0,15 M Ammoniumcitrat pH 7,5 eluiert. Die isolierten Radio-Nuklide werden in einem Beta-Antikoinzidenzzähler gemessen: 144Ce als CeO2, 137Cs als Cs-dipikrylaminat, 89Sr/90Sr als SrCO3, 90Y als Y2O3 und 140Ba als BaCO3. Die mittlere Rückgewinnung der zugesetzten Träger beträgt für Cer 95%, 85% für Caesium, 95% für Strontium, 95% für Yttrium und 65% für Barium. In Parallelbestimmungen mit Gehalten von einigen Ci/l, überschreiten die Abweichungen der Ergebnisse von den entsprechenden Mittelwerten im allgemein nicht 5%. Bei einer 30 l-Probe beträgt die untere Nachweisgrenze 0,005 Ci/l für 144Ce, 0,006 Ci/l für 137Cs, 0,005 Ci/l für 90Sr und 0,006 Ci/l für 140Ba.
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5.
Cyclic voltammetry and galvanostatic coulometry techniques were used to determine how the redox properties of osmium binuclear -oxocarboxylates [Os2 IV(-O)(-O2CR)2Cl4L2] (R = CH3, CCl3; L = PPh3 and R = CH3; L = AsPh3) are influenced by the nature of the bridging carboxylate ligand RCOO and ligand L. It was shown that all compounds in solution of dichloromethane undergo two single-electron reduction processes. The data obtained were compared with the DFT calculations of the electronic structure of the model complexes [Os2 IV(-O)(-O2CR)2Cl4L2] (R = CH3, CCl3; L = PH3 and R = CH3; L = AsH3).  相似文献   

6.
The reaction of the dinuclear complex Co2(-OOCCMe3)2(2-OOCCMe3)2bpy2 (1) with the polymer [Co(OH) n (OOCCMe3)2–n ] x afforded the unsymmetrical dinuclear complex bpyCo2(2-O,2-OOCCMe3)(2-O,O"-OOCCMe3)2(2-OOCCMe3) (2). The reaction of 2,2"-dipyridylamine with [Co(OH) n (OOCCMe3)2–n ] x gave rise to the analogous complex [(C5H4N)2NH]Co2(2-O,2-OOCCMe3)(-OOCCMe3)2(2-OOCCMe3) (3). The reaction of complex 1 with Ni4(3-OH)2(-OOCCMe3)4(OOCCMe3)2(MeCN)2[2-o-C6H4(NH2)(NHPh)]2 (4) produced an isostructural heterometallic analog of complex 2 with composition bpyM2(2-O,2-OOCCMe3)(2-O,O"-OOCCMe3)2(2-OOCCMe3) (5) (M = Co, Ni; Co : Ni = 1 : 1) and the dinuclear heterometallic complex bpy(HOOCCMe3)M(-OH2)(-OOCCMe3)2M(OOCCMe3)2[o-C6H4(NH2)(NHPh)] (6) (M = Co, Ni; Co : Ni = 0.15 : 1.85). Compounds 2 and 5 exhibit ferromagnetic spin-spin exchange interactions.  相似文献   

7.
Fluoride and sulphate complexing of Np(VI) has been studied by controlled-potential coulometry at a constant ionic strength. The values of 1 * and 2 * for fluoride complexes were found to be 9.4 and 8.9, respectively, at an ionic strength =0.5. At an ionic strength =1.0, 1 * and 2 * obtained were 6.6 and 10.5, respectively. Sulphate complexing of Np(VI) was studied only at an ionic strength =0.5. The value of 1 * obtained was 5.6.  相似文献   

8.
Chemical and electrochemical oxidation of rhodium (III) oxo-bridged carboxylate complexes was studied. The chemical [with O3 and Ce(IV) salts] or electrochemical (at potentials of 1.00-1.20 V) oxidations of the binuclear complexes [Rh2(-O)(-O2CCH3)2(H2O)6]2 + and [Rh2(-O)(-O2CCF3)2(H2O)6]2 + leads to the superoxo complexes [Rh2(-O)(O2-)(-O2CCH3)2(H2O)5]+ and [Rh2(-O)(O2 -)(-O2CCF3)2(H2O)5]+ with terminal coordination of O2-. The trinuclear acetate [Rh3(3-O)(-O2CCH3)6(H2O)3]+, unlike its trifluoroacetate analog [Rh3(3-O)(-O2CCF3)6(H2O)3]+, is oxidized only electrochemically at a potential of 1.38 V. The oxidation of [Rh3(3-O)(-O2CCH3)6(H2O)3]+ is reversible and involves formation of an unstable superoxo group O2 - between two Rh3III(3-O) cores.  相似文献   

9.
The reaction between Ru3(3-2-PhC2C=CPh)(-dppm)(CO)8 and Co2(CO)8 afforded dark red Co2Ru3(4-C2Ph)(3-C2Ph)(-dppm)(-CO)2(CO)9, shown by an X-ray structure determination to contain a strongly twisted Co2Ru3 bow-tie cluster (central Co), to which two PhC2 units derived from cleavage of the original diyne are attached. One a these is strongly interacting with four metal atoms, the other being attached in the familiar 1,22-mode. The dppm ligand remains bridging two of the Ru atoms.  相似文献   

10.
Xu  Feng  Chen  Yong-Mei  Yang  Shi-Yan  Sun  Wen-Hua  Yu  Kai-Bei 《Transition Metal Chemistry》2000,25(1):108-111
CpMoFeCo(CO)7(3-S) reacts with Cp*M(CO)3Cl or CpM(CO)3Cl (M=W, Mo) to gave the mixed-metal clusters Cp*WCpMoFe(CO)7(3-S) (1), Cp*MoCpMoFe(CO)7(3-S) (2), CpWCp*MoFe(CO)7(3-S) (3), CpMoCp*MoFe(CO)7(3-S) (4) and Cp*WCp*MoFe(CO)7(3-S) (5). The title clusters have been characterized by i.r., 1H/13C-n.m.r. spectroscopy and their compositions have been confirmed by elemental analyses. The X-ray crystal structure analysis shows the two independent enantiomeric molecules of clusters (1) in one crystal structure unit.  相似文献   

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