Complex ions linear complexes

In view of Swalin s treatment of diffusion in liquid metals. Are latter seems to be a better description. In binaty mixmres such as NaCl-KCl the equivalent conducAvities are a linear manner, but the KCl-CdCla mixture shows a marked negative departure from linear behaviour, probably because of the formation of the complex ion CdCh. ... 

Complex ions in which the central metal forms only two bonds to ligands are linear that is, the two bonds are directed at a 180° angle. The structures of CuCl2, Ag(NH3)2+, and Au(CN)2 may be represented as... 

Combining volumes, law of, 26, 236 Combustion, heat of hydrogen, 40 Complex ions, 392 amphoteric, 396 bonding in, 395 formation, 413 geometry of. 393 in nature, 396 isomers, 394 linear, 395 octahedral, 393 significance of, 395 square planar, 395 tetrahedral, 394 weak acids, 396 Compound, 28 bonding in, 306 Concentration and equilibrium, 148 and E zero s, 213 and Le Chatelier s Principle, 149 effect on reaction rate, 126, 128 molar, 72... 

Equations for the evaluation of formation constants of complexed ion species in cross-linked and linear polyelectrolyte systems. J. A. Marinsky, Ion Exch. Solvent Extr., 1973,4, 227-243 (18). 

It is then shown that (excepting the rare-earth ions) the magnetic moment of a non-linear molecule or complex ion is determined by the number of unpaired electrons, being equal to ms = 2 /S(S + 1), in which 5 is half that number. This makes it possible to determine from magnetic data which eigenfunctions are involved in bond formation, and so to decide between electron-pair bonds and ionic or ion-dipole bonds for various complexes. It is found that the transition-group elements almost without exception form electron-pair bonds with CN, ionic bonds with F, and ion-dipole bonds with H2O with other groups the bond type varies. 

Silver forms a linear complex ion with 2 neutral ammonia molecules as ligands. 

In this way we come to class III complexes, i.e. complexes in which the two sites are indistinguishable and the element has a non-integral oxidation state (delocalized valence). Usually one divides this class in two subclasses. In class IIIA the delocalization of the valence electrons takes place within a cluster of equivalent metal ions only. An example is the [NbgCli2] ion in which there are six equivalent metal ions with oxidation state + 2.33. In class IIIB the delocalization is over the whole lattice. Examples are the linear chain compound K2Pt(CN)4.Bro.3o. 3H2O with a final oxidation state for platinum of 2.30, and three-dimensional bronzes like Na WOg. 

Of particular importance in structural chemistry is the concept of hybridization, that is, the construction of linear combinations of atomic orbitals that transform according to the symmetry of the structure. For the present, a simple illustration is provided by the hybridization of atomic orbitals in a molecule or complex ion of trigonal structure. 

Likewise, it is easy to rationalize how Ag+ (a d10 ion) can form a linear complex with two ligands like NH,. 

In this language, the cyclic (LiF) complexes are closed-CT structures (and thus maximally cooperative), whereas the corresponding linear complexes have reactive open-CT sites at both ends. As shown in Table 2.1, the energetic consequences of such open-CT versus closed-CT topology are considerable, with cyclic (LiF) complexes being stabilized, e.g., by more than 40kcalmol 1 for n = 3. Thus, a simple ion-dipole or dipole-dipole picture is clearly inadequate for chemical accuracy. 

The preparation and reactions of metal cluster ions containing three or more different elements is an area with a paucity of results. The metal cyanides of Zn, Cd (258), Cu, and Ag (259) have been subjected to a LA-FT-ICR study and the Cu and Ag complex ions reacted with various reagents (2,256). The [M (CN) ]+ and [M (CN) +11 ions of copper, where n = 1-5, were calculated to be linear using the density functional method. The silver ions were assumed to have similar structures. The anions [M (CN) +1 of both copper and silver were unreactive to a variety of donor molecules but the cations M (CN) H + reacted with various donor molecules. In each case, where reactions took place, the maximum number of ligands added to the cation was three and this only occurred for the reactions of ammonia with [Cu2(CN)]+, [Cu3(CN)2]+, [Ag3(CN)2]+, and [ Ag4(CN)3]+. Most of the ions reacted sequentially with two molecules of the donor with the order of reactivity being Cu > Ag and NH3 > H2S > CO. 

Most network structures involving crown ethers are simple hydrogen bonded chains where the crown forms second sphere coordination interactions with a complex ion. These are known for [18]crown-6, [15]crown-5 and [12]crown-4 hosts with a variety of metal complexes [17-25]. For instance when combined with the small [12] crown-4, the perchlorate salts of Mn(II), Ni(II) and Zn(II) form polymeric chain structures with alternating crown ethers and [M(H20)6]2+ cations [19]. Similarly the larger [18]crown-6 forms simple linear chains with metal complexes and cations such as fra s-[Pt(NH3)2Cl2] [20], [Cu(NH3)4(H20)]2+ (Fig.2) [21],and [Mg(H20)5(N03)] + [22],... 

Thus, the unknown values of i ed and AGf can be determined from the intercept and slope of the linear plots of (AG /e) versus (LGtJey as shown in Fig. 9. The °red values of various metal ion-carbonyl complexes thus obtained are summarized in Table 2 [113,114]. The °rea values of the triplet excited states are obtained by adding the triplet excitation energies and are listed in Table 2. 

Chlorpromazine reacts with 9-bromomethylacridine in acetonitrile to give a quaternary ammonium derivative, which on subsequent photolysis yields fluorescent products [136]. The fluorescence is linear over the analyte range of 0.05 to 1 pg. Lumogallion 5-chloro-3-(2,4-dihydroxy-phenylazo)-2-hydroxybenzenesulfonic acid forms a fluorescent ion-pair complex with chlorpromazine in the presence of Al(III) which is extracted (without interference from primary or secondary amines) up to equimolar concentrations [137,138]. 

New modified polymeric electrodes selective to procaine and other local anaesthetic compounds were reported [72]. The electrode was constructed by incorporating the ion-pair complex of procaine with tungsto-phosphoric acid into ethylene-vinyl acetate copolymer. Best results were obtained with 1 1 nitrobenzene-dioctyl phthalate as a plasticizer. The calibration graph was linear fi om 18 p to 10 mM of procaine. When these electrodes were applied to the determination of the drug in pharmaceutical formulations, the recoveries were found to be quantitative. 

We can now make sensible guesses as to the order of rate constant for water replacement from coordination complexes of the metals tabulated. (With the formation of fused rings these relationships may no longer apply. Consider, for example, the slow reactions of metal ions with porphyrine derivatives (20) or with tetrasulfonated phthalocyanine, where the rate determining step in the incorporation of metal ion is the dissociation of the pyrrole N-H bond (164).) The reason for many earlier (mostly qualitative) observations on the behavior of complex ions can now be understood. The relative reaction rates of cations with the anion of thenoyltrifluoroacetone (113) and metal-aqua water exchange data from NMR studies (69) are much as expected. The rapid exchange of CN " with Hg(CN)4 2 or Zn(CN)4-2 or the very slow Hg(CN)+, Hg+2 isotopic exchange can be understood, when the dissociative rate constants are estimated. Reactions of the type M+a + L b = ML+(a "b) can be justifiably assumed rapid in the proposed mechanisms for the redox reactions of iron(III) with iodide (47) or thiosulfate (93) ions or when copper(II) reacts with cyanide ions (9). Finally relations between kinetic and thermodynamic parameters are shown by a variety of complex ions since the dissociation rate constant dominates the thermodynamic stability constant of the complex (127). A recently observed linear relation between the rate constant for dissociation of nickel complexes with a variety of pyridine bases and the acidity constant of the base arises from the constancy of the formation rate constant for these complexes (87). 

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