Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Anions complex

Uranium ores are leached with dilute sulfuric acid or an alkaline carbonate [3812-32-6] solution. Hexavalent uranium forms anionic complexes, such as uranyl sulfate [56959-61-6], U02(S0 3, which are more selectively adsorbed by strong base anion exchangers than are other anions in the leach Hquors. Sulfate complexes are eluted with an acidified NaCl or ammonium nitrate [6484-52-2], NH NO, solution. Carbonate complexes are eluted with a neutral brine solution. Uranium is precipitated from the eluent and shipped to other locations for enrichment. Columnar recovery systems were popular in South Africa and Canada. Continuous resin-in-pulp (RIP) systems gained popularity in the United States since they eliminated a difficult and cosdy ore particle/leach hquor separation step. [Pg.387]

The porphyrin ligand can support oxidation states of iron other than II and III. [Fe(I)Por] complexes are obtained by electrochemical or chemical reduction of iron(II) or iron(III) porphyrins. The anionic complexes react with alkyl hahdes to afford alkyl—iron (III) porphyrin complexes. Iron(IV) porphyrins are formally present in the carbene, RR C—Fe(IV)Por p.-carbido, PorFe(IV)—Fe(IV)Por nitrene, RN—Fe(IV)Por and p.-nittido, PorFe(IV)... [Pg.442]

The most common oxidation state of niobium is +5, although many anhydrous compounds have been made with lower oxidation states, notably +4 and +3, and Nb can be reduced in aqueous solution to Nb by zinc. The aqueous chemistry primarily involves halo- and organic acid anionic complexes. Virtually no cationic chemistry exists because of the irreversible hydrolysis of the cation in dilute solutions. Metal—metal bonding is common. Extensive polymeric anions form. Niobium resembles tantalum and titanium in its chemistry, and separation from these elements is difficult. In the soHd state, niobium has the same atomic radius as tantalum and essentially the same ionic radius as well, ie, Nb Ta = 68 pm. This is the same size as Ti ... [Pg.20]

Weaker complex ions may also form with orthophosphates, eg, CaH2PO" 4 in mildly acidic solutions of calcium phosphates, and FeHPO" 4 as a colorless species in impure phosphoric acid. Anionic complexes such as Fe(HPO 2 o known. [Pg.340]

Pu(IV) forms polyatomic complexes with inorganic and organic ligands. As the number of anionic ligands increases, cationic, neutral, and anionic complexes form and the sequential stabiUty constants, typically decrease. For the following reaction, where M is Pu + and L is a ligand,... [Pg.199]

Evidence foi the anionic complex PuCP is the precipitation of complex halides such as Cs2PuClg from concentrated HCl (aq). The ability of Pu(IV) to form stable nitrate complexes provides the basis for the Purex and ion-exchange (qv) process used in the chemical processing of Pu (107). Pu(VI) is similar to Pu(IV) in its abihty to form complex ions. Detailed reviews of complex ion formation by aqueous plutonium are available (23,94,105). [Pg.199]

Certain neutral technetium complexes can be used to image cerebral perfusion (Fig. 4). Those in Figure 4a and 4b have been approved for clinical use. Two other complexes (Fig. 4c and 4d) were tested in early clinical trials, but were not developed further. An effective cerebral perfusion agent must first cross the blood brain barrier and then be retained for the period necessary for image acquisition. Tc-bicisate is retained owing to a stereospecific hydrolysis in brain tissue of one of the ester groups to form the anionic complex TcO(ECD) , which does not cross the barrier. This mechanism of retention is termed metaboHc trapping. [Pg.478]

Anionic Complexes. Compounds of tungsten with acid anions other than haUdes and oxyhaUdes are relatively few in number, and are known only in the form of complex salts. A number of salts containing hexavalent tungsten are known. Potassium octafluorotungstate [57300-87-5] K WFg, can be prepared by the action of KI on W(CO)g in an IF medium. The addition of tungstates to aqueous hydrofluoric acid gives salts that are mostly of the type M(I)2(W2F. Similarly, double salts of tungsten oxydichloride are known. [Pg.291]

U(IV) nitrates have been obtained from aqueous solution, but a number of anionic complexes of general formula M2[U(N02)g], where M = NH Rb, Cs, and M[U(N02)g] 8H20, where M = Mg, Zn have been isolated and characterized. These soHds contain the 12 coordinate anionic U(IV) center shown in (2) (158). Neutral, U(IV) nitrate complexes of formula U(N02)4L2 (3) (L = OP(CgH )2, OP(NC4Hg)2) have also been isolated from aqueous solutions and stmcturaHy characterized (159). [Pg.326]

Sulfates. Sulfate ions strongly complex zirconium, removing hydroxyl groups and forming anionic complexes. With increasing acidity, all hydroxyl groups are replaced zirconium sulfate [7446-31-3] Zr(S04)2-4H20, with an orthorhombic stmcture (206), can be crystallized from a 45% sulfuric acid solution. Zirconium sulfate forms various hydrates, and 13 different crystalline Zr(S0 2 5 2 [14644-61-2] systems are described in Reference 207. [Pg.437]

Cd(OH)2 is much more basic than Zn(OH)2 and is soluble ia 5 NaOH at 1.3 g/L as the anionic complex tetrahydroxocadmate [26214-93-7] Cd(OH) 4. Technical-grade Cd(OH)2 sold for 74/kg ia 1991 and its most important utihty is as the active anode ia rechargeable Ni—Cd and Ag—Cd storage batteries. The chemical reaction responsible for the charge—discharge of the batteries is (35) ... [Pg.395]

The palladium chloride process for oxidizing olefins to aldehydes in aqueous solution (Wacker process) apparendy involves an intermediate anionic complex such as dichloro(ethylene)hydroxopalladate(II) or else a neutral aqua complex PdCl2 (CH2=CH2)(H2 0). The coordinated PdCl2 is reduced to Pd during the olefin oxidation and is reoxidized by the cupric—cuprous chloride couple, which in turn is reoxidized by oxygen, and the net reaction for any olefin (RCH=CH2) is then... [Pg.171]

Cryptands, 7, 731-761 alkali metal complexes NMR, 7, 740 reactivity, 7, 743-744 alkaline earth complexes reactivity, 7, 743-744 anion complexes, 7, 747-748 applications, 7, 753-761 as biological models, 7, 753-754 bis-tren... [Pg.588]

The quaternary ammonium salts (QAS) are widely used as ionofores of ion-selective electrodes and extractants of metals halogenic anion complexes. The influence of the QASes nature with various methyl groups contents on the cadmium extraction from bromide media has been investigated. [Pg.264]

During the course of these mechanistic studies a wide range of possible applications of this reaction have been revealed. When the reduction is carried out with lithium aluminum deuteride and the anion complex decomposed with water, a monodeuterio compound (95) is obtained in which 70% of the deuterium is in the 3a-position. Reduction with lithium aluminum hydride followed by hydrolysis with deuterium oxide yields mainly (70 %) the 3j5-di-epimer (96), while for the preparation of dideuterio compounds (94) both steps have to be carried out with deuterated reagents. ... [Pg.174]

Coordination by halide ions is rather weak, that of especially so, but from non-aqueous solutions it is possible to isolate anionic complexes of the type [LnXg]. These are apparently, and unusually for Ln , 6-coordinate and octahedral. The heavier donor atoms S, Se, and As form only a few... [Pg.1247]

Molybdenum and tungsten hexacarbonyls are able to form anionic complexes (AsPli4)2[(OC)4M( -pz)2M(CO)4] upon reaction with sodium pyrazolate and PluAsCl (72CB3203). The cationic complexes [(rj -Cp)2Mo(/Lt-pz)2Mo(rj -Cp)2] " (n = 2, 3) are known as well (74HCA1988). The other representatives of the complexes containing an exobidentate ligand (26) are derived from 4//-pyrazoles [70ZAAC(379)169]. [Pg.164]


See other pages where Anions complex is mentioned: [Pg.348]    [Pg.395]    [Pg.917]    [Pg.220]    [Pg.195]    [Pg.504]    [Pg.477]    [Pg.226]    [Pg.588]    [Pg.588]    [Pg.747]    [Pg.54]    [Pg.91]    [Pg.612]    [Pg.674]    [Pg.735]    [Pg.966]    [Pg.968]    [Pg.970]    [Pg.993]    [Pg.1089]    [Pg.1131]    [Pg.1276]    [Pg.134]    [Pg.57]    [Pg.184]    [Pg.184]    [Pg.185]    [Pg.209]    [Pg.43]    [Pg.73]    [Pg.267]   
See also in sourсe #XX -- [ Pg.132 ]




SEARCH



Acetonitrile Complex Cations with Triflate Anions

Actinide anionic complexes

Alkali metal complexes acid anions

Alkaline earth metal complexes anions

Alkylidyne-metal complexes anion structure

Alkyne complexes anionic donor ligands

Allyl reaction with anionic chromium complex

Aluminium anionic complexes

Aluminum complex compounds anions, oxalato

Anion Complexes with Calixarenes

Anion Separations Involving Complex Formation

Anion acid complexes

Anion cation complexing agents

Anion complex notation

Anion complexation

Anion complexation

Anion complexer strength

Anion complexes anionic adducts

Anion complexes gold dithiocarbamates

Anion complexes mono

Anion complexes nickel dithiocarbamates

Anion copper-containing complex

Anion exchange complex

Anion exchangers, complexation

Anion lanthanide complexation

Anion recognition lanthanide complexes

Anion relative complexation ability

Anion structures cyanide-bridged complexes

Anion structures pentanuclear complexes

Anion structures trinuclear complexes

Anion-cation sublattices, complex

Anion-host complexes

Anion-neutral complex

Anionic alkyl and aryl chromium complexes

Anionic alkyl complexes

Anionic bromide complexes

Anionic carbonyl complexes

Anionic complexes macrocycles

Anionic complexes, trivalent uranium

Anionic halide complexes

Anionic hydroxy complexes

Anionic iridium complexes

Anionic ligands five-coordinate complexes

Anionic palladium complexes

Anionic polymerization alkali metal complexes

Anionic polymerization complex architectural polymer

Anionic polymerization complex bases

Anionic rhodium complexes

Anionic ruthenium complexes

Anionic ruthenium complexes, luminescence

Anionic structure mono complexes

Anionic tetrahedron complex

Anionic thiocarbonyl complex

Anionic-cationic complex

Anionic—amphoteric complex

Anions excited state complexes

Anions lanthanide complexes

Anions ruthenium polypyridine complexes

Anions tropolonato complexes

Anions, tendency toward complex formation

Anodic Homocoupling of Anions, at-Complexes, Organometallics and Phenolates

Arsenic chloride complex anions

Aza-macrocycles for anion complexation

Beryllium complex compounds, anions

Beryllium complexes anionic

Boron complexes anionic

Boron transition-metal complex anion

Boron trifluoride complex anion formation

Calixarenes anion complexation

Carbene complex chromium anionic

Carbene complexes, alkyl pentacarbonylalkylation anions

Carborane anions, metal complexes

Cation-acid anion complexes

Cation-anion complexes

Cation/anion complex formation

Cationic and anionic complexes

Cationic and anionic complexes (PPh

Cationic-anionic sublattices, complex

Cationic-anionic sublattices, complex oxidation

Chromium anionic complexes

Chromium complex compounds anions, oxalato

Chromium complex compounds, anions

Chromium complex tetracarbonyl anion

Chromium complexes carbonyl anion

Cobalt anionic sandwich complexes, reaction

Cobalt complex compounds anions, carbonyl

Cobalt complex compounds, anions

Cobalt complex compounds, anions structure

Cobalt complex compounds, anions with pyridine

Cobalt complexes, anionic

Complex Formation of Anionic Surfactants with Aromatic Compounds

Complex alkyl-metal anions

Complex anionic

Complex anionic

Complex anions formation

Complex anions nomenclature

Complex anions rotation

Complex anions sizes

Complex anions stability

Complexation anionic

Complexes anion centred

Complexes anionic acetato

Complexes anionic metal hydrides

Complexes of Thiazyl Halides NSX (X F, Cl, Br), NSF3 and the Anion

Complexes of the 3 anion

Complexes of the and 2-Anions

Complexes with monocarboxylic acid anions

Complexes with weakly bonded anions

Complexes, cationic and anionic (PMe

Complexes, cationic and anionic (cont

Compounds with Complex Anions

Coordination geometry in pentacoordinate anionic complexe

Copper complex anion hosts

Copper complex compounds anions, with

Copper complex compounds, anions

Copper complexes anionic

Cr-bonded anionic carbon complexes

Cr-bonded anionic carbon complexes, alkyl

Cyclopentadienyl anion dinuclear complexes

Cyclopentadienyl complexes anionic

Cytochrome-anion complex

Dye Salts with Complex Anions

Electrosynthesis of complexes containing weakly acidic anions

Enolate anions, malonate complexes

Fluorides complex anion

Formation of a (Non-solvated) Complex Anion

Formazan anionic complexes

Formyl complexes anions

From complex transition metal anions and halides

Gallium transition-metal complex anion

Glycine, complex anions with

Gold complex compounds, anions

Gold complexes anionic nitrogen donor ligands

Guanidines guanidine-anion complexes

Halides anionic vanadium complexes

Halides transition-metal complex anion

Heterocycle-lanthanide complexes, anion

Heterogeneous Two-Phase Distribution Analysis of Complexation in Anion Exchangers

Hexacoordinate silicon compounds anionic complexes

Homoleptic anionic complexe

Homoleptic anionic complexe ligands

Homoleptic anionic complexe methyl ligands

Hydride anionic complexes

Hydrogen-bond complexes anion recognition

Hydroxide anion complexes

III) Complexes with the Weakly Bonded Anions and

Indium transition-metal complex anion

Iridium complex compounds anions, with pyridine, cis- and

Iridium complexes hydroxy anions

Iron , hydrido complex anion

Iron complex anion

Iron complex compounds anions, carbonyl

Iron complex compounds, anions

Iron complex compounds, anions potassium salt

Iron complex compounds, anions with pyridine

Iron complex compounds, anions, oxalato

Iron complexes anionic

Iron, anionic carbonyl complexes

Kinetics complex anions

Labile Complexes as Anion Hosts

Macrobicycles anionic complexes

Macromonocycles anionic complexes

Macrotricycles anionic complexes

Manganese complex compounds anions, carbonyl

Manganese complexes anions

Manganese complexes carbonyl anions

Mercury anionic complexes distribution

Metal Complexes and Anions

Metal Complexes of Sulfimido, and Sulfenamido Anions

Metal complexes, anion sensing

Metal-carbene complexes anions

Metals in complex anions

Molybdenum complex compounds, anions, with

Molybdenum complexes, anion

Molybdenum complexes, anion, with

Mono complexes anionic adducts

Neutral and Anionic Complexes

Nickel , hydrido complex anion

Nickel anionic ethylene complexes

Nickel complex compounds, anions

Nickel complexes anions

Niobium complexes anionic

Nitrogen heterocycles, anionic complexes

Osmium , hydrido complex anion

Palladium complex compounds, anions

Pentacoordinate germanium complexes anionic

Phosphides with Complex Anions

Phosphorescence colors, anionic complexes

Platinum complex compounds anions, with 1,4-butadiene

Platinum complex compounds anions, with ethylene

Platinum complex compounds, anions

Platinum complexes anionic carbonyl clusters

Platinum hydrido complex anions

Polyazamacrocycles anionic complexes

Polynuclear anion-bridged complexes

Protonated aza-macrocycles, for anion complexation

Protonic Acids with Non-Complex Anions

Protonic acids with complex anions

Rare Earth Complexes as Luminescent Chemosensors for Anions

Reactions of Anionic Complexes with Organic Halides

Receptor-anion complex

Rhenium , hydrido complex anion

Rhodium complex compounds anions, aquo

Rhodium complexes anions

Rhodium complexes bidentate anions

Ruthenium , hydrido complex anion

Ruthenium complexes, anion

Ruthenium complexes, reactions anionic species

Selenium complex anions

Seleno anions metal complexes

Silicon transition-metal complex anions

Silver complexes anionic

Silyl-transition metal complexes anionic derivatives

Solvents Ionic with complex anion

Steroid-based anion complexation agents

Strong Complexation in Anion-Exchanger Phase

Structure enzyme-anion complexes

Substrate anion cobalt complex

Substrate binding enzyme-anion complexes

Synthesis of complexes containing classically noncoordinating anions as ligands

Tantalum complexes anionic

Tantalum complexes anions

Thallium complexes anionic derivatives

The Role of Redox Processes in Reactions Catalyzed by Nickel and Palladium Complexes with Anionic Pincer Ligands

Thio anions metal complexes

Three-Phase Distribution Analysis for Complexation in Anion Exchangers

Titanium anionic complexes

Titanium complexes anionic ligands

Transition Metal Complexes Containing Anionic or Cationic Ligands

Transition metal complexes with weakly bonded anions

Transition-metal complex anions

Trialkyl germanium reaction with anionic vanadium complexes

Triphospholyl anions, formation ruthenium cyclopentadienyl complexes

Tris borate anion, complex with

Tropolonato complexes anionic

Tungsten complex compounds, anions

Tungsten complexes anionic pentacarbonyl

Vanadium complexes carbonyl anion

Xanthate complexes anion structures

Zinc complex compounds, anions

Zirconium complex compounds, anion

© 2024 chempedia.info