Complex compound

In Section 24 it was shown that, under favorable conditions, two oxides of the same metal, in different states of valency, may form solid solutions which have been described as compounds with variable composition. The stabilizing factor in this case is the increase in entropy, due to the random distribution of the two positive ions these systems, strictly speaking, are stable only at elevated temperature. The conditions may be such that two oxides form a real compound, because this process is connected with a decrease in energy. The compounds formed in this way have a stoichiometric composition, with two kinds of positive ions in fixed positions, so arranged that the energy of the system is minimal. A good example of a compound of this type is Fe304. 

In this group, and in many others, e.g. KBF4 and K2PtCl65 the existence of the complex ions in solutions was known long before their existence in the solid state was proved by x-ray analysis. The essential point in the process of complex formation 

The resemblance between the two sets is not merely a formal one it has been shown by x-ray analysis that BaS04 and KBF4 have exactly the same structure, K+ ions in KBF4 taking the place of the Ba2+ ions in BaS04, and both compounds containing a tetrahedral 

The reasons for making a distinction between complexes like KBF4 and cnon-complexs compounds like BaS04 will now be discussed In most textbooks KBF4 is called a complex, and BaS04 a normal compound or an oxygen salt, simply because a structural formula 

If the oxygen in CaO is replaced by the group CO , then a lattice essentially similar to that of CaO is obtained. It is not exactly the same, as the shape of the CO - is different from that of the 02 ion, but each CO ion is still surrounded by six Ca2+ ions. Consequently, there is no basis whatever for employing the formula 

In strongly acidic media, cupferron, the ammonium salt of N-nitroso-N-phenylhy-droxylamine, seems to form with TcOf adduct [(Cupf) (Tc04) [ or an adduct with pertechnetic acid, which can be extracted from 6 M HCl into ether by 99 %. The occurrence of any significant reduction was not observed. Tc(IIl), prepared by coulometric reduction of pertechnetate, was extracted as a cupferrate into ether up to 26% [152], 

Potassium xanthatc reduces pertechnetate and forms a technetium complex in a 

5 N aqueous solution of HCl, H2SO4 or H( I04, from which more than 99 % of technetium could be extracted into carbon tetrachloride at 20 C. The concentration of potassium xanthate was 0.1 M. Perrhenate remained entirely in the aqueous phase, thus separation from technetium could be readily achieved. Instead of carbon tetrachloride. other extractants like chloroform. 1,1,1-trichlorocthane, xylene or isopropyl ether are also suitable [153[. 

In addition, tetramethylenedithiocarbamatc was used for reduction of TcOj, chelation, and extraction of the complex into chloroform from hydrochloric acid solution. More than 99 % of the technetium can be extracted into chloroform when the HCl concentration is 0.01 VI. In contrast to technetium most of the accompanying radionuclides in low-lcvel radioactive wastes are not extracted into the organic phase at high HCl concentrations, c.g. 4 M HCl, except Co and Ag. The suitable concentration of tetramethylencdithiocarbamate ranged between 110 and 1.5 10 M (154[. 

Potassium thiocyanate reduces pertechnetate in aqueous hydrochloric acid solution and forms thiocyanato complexes of technetium that arc extractable by a solution of 0.1 M 2-hexylpyridinc in benzene. Also Mo(VI), Au(IlI), As(III). Fe(III), Zn(II), and Hg(ll) are extracted under similar conditions, lire equilibrium is attained in about 3 

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Marcus R A 1973 Semiclassical theory for collisions involving complexes (compound state resonances) and for bound state systems Faraday Discuss. Chem. Soc. 55 34—44... 

The transition elements are often said to exhibit variable valency. Because they so readily form complex compounds, it is better to use the term variety of oxidation states . The states usually found for the elements Sc-Zn are ... 

We shall only be concerned here with those reactions, which have been used in constructions of the carbon skeletons of complex compounds with concomitant regioselective incorporation of the double bond. 1,2-Eliminations are discussed on p. 137ff. 

All these highly complex compounds are produced on the industrial scale from microorganisms. Only the S-lactams are modified chemically after the isolation from the fermentation broth. We shall describe these partial syntheses as well as some typical synthetic sequences of academic total syntheses. 

Other eactions. Most of the metabohtes of cortisol are neutral (alcohol or glucuronide complex) compounds. However, oxidation at C-21 to C-21 carboxyhc acids (17) accounts for some of the identifiable metabohtes of glucocorticoids (18). 

Simple ABO compounds in addition to BaTiO are cadmium titanate [12014-14-17, CdTiO lead titanate [12060-00-3] PbTiO potassium niobate [12030-85-2] KNbO sodium niobate [12034-09-2], NaNbO silver niobate [12309-96-5], AgNbO potassium iodate [7758-05-6], KIO bismuth ferrate [12010-42-3], BiFeO sodium tantalate, NaTaO and lead zirconate [12060-01 -4], PbZrO. The perovskite stmcture is also tolerant of a very wide range of multiple cation substitution on both A and B sites. Thus many more complex compounds have been found (16,17), eg, (K 2 i/2) 3 ... 

On aging, many complex compounds precipitate from the concentrated acid to yield sludge. Examples of these compounds are (38)... 

Some of the newer compounds may contain both saturated and unsaturated rings, heteroatoms such as oxygen, nitrogen, or sulfur, and halogen substituents. Others, such as synthetic pyrethroids, may have one or more chiral centers, often needing stereospecific methods of synthesis or resolution of isomers (42). Table 4 Hsts examples of some more complex compounds. Stmctures are shown ia Eigure 1 (25). 

Tannate Complexation. Certain dmgs, those that contain amine groups, complex readily with tannic acid. Such complexes release the dmg gradually and uniformly. The rate seems to be affected by the pH and the electrolytes present in the gastrointestinal tract. At lower pH, the dmg is released more quickly. Other complexing compounds have also been used. 

The most common oxidatiou states and corresponding electronic configurations of rhodium are +1 which is usually square planar although some five coordinate complexes are known, and +3 (t7 ) which is usually octahedral. Dimeric rhodium carboxylates are +2 (t/) complexes. Compounds iu oxidatiou states —1 to +6 (t5 ) exist. Significant iudustrial appHcatious iuclude rhodium-catalyzed carbouylatiou of methanol to acetic acid and acetic anhydride, and hydroformylation of propene to -butyraldehyde. Enantioselective catalytic reduction has also been demonstrated. 

Quaternary ammonium compounds are usually named as the substituted ammonium salt. The anion is Hsted last (3). Substituent names can be either common (stearyl) or lUPAC (octadecyl). If the long chain in the compound is from a natural mixture, the chain is named after that mixture, eg, taHowalkyL Prefixes such as di- and tri- are used if an alkyl group is repeated. Complex compounds usually have the substituents Hsted in alphabetical order. Some common quaternary ammonium compounds and their appHcations in patent Hterature are Hsted in Table 1. 

By reactive sputtering, many complex compounds can be formed from relatively easy-to-fabricate metal targets, insulating compounds can be deposited using a d-c power supply, and graded compositions can be formed, as described. The process, however, is compHcated. 

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. 

Chemica.1 Remova.1. Phosphoms can be precipitated with lime to form Ca2(P0 2- The actual composition of the precipitate is a complex compound called apitate. Achieving minimum phosphoms concentrations requires a pH in excess of 10.5. Alum or iron will precipitate phosphoms as AIPO4 or FePO. This procedure is generally employed in conjunction with the activated sludge process, in which the coagulant is added at the end of the aeration basin or between the aeration basin and the final clarifier. 

Advances in the technology of chemical analysis and the abiUty to analy2e for trace amounts of complex compounds now make it possible to combine analytical information with sensory analysis to identify taste characteristics and faciUtate process control. 

SoHd lubricants ate added to help control high friction characteristics in high speed or heavy-duty appHcations where high temperatures are generated. Molybdenum disulfide [1317-33-5] M0S2, may be used alone or in a complex compound formed by grinding with fine natural graphite, and zinc sulfide [1314-98-3] ZnS. Other compounds include calcium fluoride, cryoHte [15096-52-3] Na AlF, rare-earth oxides, and metal sulfides, eg, iron, antimony, or zinc (see LUBRICATION AND LUBRICANTS). 

In the presence of Eriedel-Crafts catalysts, gaseous ethyl chloride reacts with ben2ene at about 25°C to give ethylben2ene, three diethylben2enes, and other more complex compounds (12) (see Xylenes and ethylbenzene). Aromatic compounds can generally be ethylated by ethyl chloride in the presence of anhydrous aluminum chloride (see Eriedel-Crafts REACTIONS). Ethyl chloride combines directly with sulfur trioxide to give ethyl chlorosulfonate,... 

Copper(I) chloride is insoluble to slightly soluble in water. SolubiUty values between 0.001 and 0.1 g/L have been reported. Hot water hydrolyzes the material to copper(I) oxide. CuCl is insoluble in dilute sulfuric and nitric acids, but forms solutions of complex compounds with hydrochloric acid, ammonia, and alkaU haUde. Copper(I) chloride is fairly stable in air at relative humidities of less than 50%, but quickly decomposes in the presence of air and moisture. 

The anthocyanins are pH sensitive. Their color, in part, is deterrnined by the pH of the sap. Cyanin, for example, is red at pH 3, violet at 8, and blue at 11. However, there are other factors that affect the colors of the anthocyanins metallic salts, notably iron and aluminum, react with those anthocyanins containing vicinal hydroxy groups and produce highly colored complex compounds. Other factors are the colloidal condition of the cell sap and copigmentation (91). 

The organizing committee extends a cordial invitation to participate in International conference on Analytical Chemistry and Chemical Analysis (AC CA-05) which is hold in scenic city of Kyiv, Ukraine, from. Septemher 12 to 18,2005. Tills conference belongs to die series of Ukrainian conferences in analytical chemistry established in 1970 by Ukrainian chemical society and chemical division of Ukrainian Academy of. Sciences. AC CA-05 is a 7 conference in analytical chemistry in Ukraine and it is dedicated to the centenary of the birth of the outstanding Ukrainian scientist, Anatoly K. Babko for his expertise in analytical chemistry and in the chemistry of complex compounds. Tlie current conference is organised by Analytical Scientific Council at Academy of Sciences of Ukraine under collaboration with European Association for Chemical and Molecular Sciences (EuClicMS) and sponsored by Intemational Union of Pure and Applied Chemistry (lUPAC) and by the Intemational Association for the Promotion of Co-operation with Scientists from the New Independent States of the Eormer Soviet Union (INTAS). 

In October, 2005 the Ukrainian scientific community will celebrate the centenary of the birth of the outstanding Ukrainian scientist, Anatoly K. Babko for his expertise in analytical chemistry and in the chemistry of complex compounds. 

The scientific interests of Anatoly K. Babko ranged widely, especially in regard to fundamental aspects of analytical chemistry, applications of organic reagents in inorganic analysis, chemistry of complex compounds (including heteropolyacids), analytical applications of complex compounds in photometry, luminescence and chemiluminescence, ion chromatography, and liquid-liquid extraction. 

A significant achievement of Anatoly K. Babko was in the area of systematic physicochemical research of complex compounds in solution based on their photometric properties. Anatoly K. Babko showed the stability constants of complexes to be highly important, and demonstrated the relevance of the stepwise character of the dissociation of complex compounds. 

Complex Compounds in Solution was quoted 250 times in the same period. 

SYNTHESIS AND INVESTIGATION OF COMPLEX COMPOUNDS OF IRON (II) AND HYDROXYLAMINE... 

Bankovskii Yu.A. Chemistry of Internal Complex Compounds of 8-Mercaptoquinoline and Its Derivatives (in Russian). Riga Zinatne, 1978. 488 p. 

The voltammograms of complex compounds of iridium with azodye appears considerably more clear separate than in the case of tritane dyes, but a sensitivity and selectivity of this method is considerably less. 

It is set that the ion of Pd(II) forms polai ogphic active complex compound with o-hydroxysubstitution azodyes - tropeolin 0 (acetate buffer solution E= -0,58V). The limit of detection Pd(II) ions is 2x10 mol/1. Instead complexforming between the ions Co(II), Ni(II) and tropeolin 0 in the optimum terms of the Pd(II) determination in general is absent. It enables to conduct the Pd(II) determination in presence the 200-multiple surpluses Co(II) and 80-multiple surpluses Ni(II). 

Mercaptoquinoline is not dissolved in chloroform but forms 8,8 -di-quinolyldisulfide as a contaminant at storage which is dissolved in chloroform and interferes to following coulometric determination of the complex compounds. 8-Mercaptoquinoline was rinsed by same portions of chloroform to remove the contaminants. 

Development of extraction-free photometric procedures for the determination of traces of metals for which hygienic and environmental regulations have been established is an urgent problem. For solution of this problem we used as an organic reagent l-(2- pyridylazo)-naphtol-2 (PAN) which forms intensely coloured complex compounds with many metals and is frequently used for their extraction-photometric determination however these procedures did not find wide application in water analysis due to lack of selectivity and necessity of using organic solvents. 

Flumequine is shown to form a complex compound with terbium(III), whose fluorescence spectmm has one band with a maximum at 545 nm (emission of terbium(III)), it corresponds to the transition. The... 

It has been established, that both DN and Ibp form complex compounds with ions Eu(III), Sm(III), Tb(III) and Dy(III), possessing luminescent properties. The most intensive luminescence is observed for complex compounds with ion Tb(III). It has been shown, that complexation has place in low acidic and neutral water solutions at pH 6,4-7,0. From the data of luminescence intensity for the complex the ratio of component Tb Fig was established equal to 1 2 by the continuous variations method. Presence at a solution of organic bases 2,2 -bipyridil, (Bipy) and 1,10-phenanthroline (Phen) causes the analytical signal amplification up to 250 (75) times as a result of the Bipy (Phen) inclusion in inner coordination sphere and formation of different ligands complexes with component ratio Tb Fig Bipy (Phen) = 1 2 1. 

Thermodynamic data show that the stabilities of the caesium chloride-metal chloride complexes are greater than the conesponding sodium and potassium compounds, and tire fluorides form complexes more readily tlrair the chlorides, in the solid state. It would seem that tire stabilities of these compounds would transfer into tire liquid state. In fact, it has been possible to account for the heats of formation of molten salt mixtures by the assumption that molten complex salts contain complex as well as simple anions, so tlrat tire heat of formation of the liquid mixtures is tire mole fraction weighted product of the pure components and the complex. For example, in the CsCl-ZrCU system the heat of formation is given on each side of tire complex compound composition, the mole fraction of the compound... 

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