Metal ions complexes with

Several solvents, such as cupriethylenediamine (cuen) hydroxide [111274-71 -6] depend on the formation of metal—ion complexes with ceUulose. Although not as widespread in use as the viscose process, cuen and its relatives with different metals and ammonium hydroxide find substantial industrial use (87). The cadmium complex Cadoxen is the solvent of choice in laboratory work (91). 

Multinuclear ds-d10 metal ion complexes with sulphur-containing ligands. J. P. Fackler, Prog. Inorg. Chem., 1976, 21, 55-90 (73). 

It is not an exaggeration to say that electrospray has introduced a new era, not only for the analytical mass spectroscopist, but also for the more physically oriented researcher interested in physical measurements involving the above ions, which are of such great importance in condensed-phase ion chemistry. In particular, gas-phase ions produced by electrospray allow, for the first time, thermochemical measurements involving ions of biochemical significance such as protonated peptides, deprotonated nucleotides, and metal ion complexes with peptides and proteins. It is to be expected that such data will be of importance in the development of theoretical modeling of the state of these systems in the condensed phase.34,35... 

Fackler, John P., Jr., Multinuclear d5-d10 Metal Ion Complexes with... 

Alkoxynitrenium ion formation in hydroxylic and non-hydroxylic organic solvents has been effected by treating A-alkoxy-A-chloroamides with Lewis acids, typically silver and zinc ions . Metal ion complexation with the chlorine lowers the energy of the orbital resulting in elimination of metal chloride. If silver acetate is utilized, the alkoxynitrenium ion can be scavenged by acetate to yield A-acetoxy-iV-alkoxybenzamides (21) (equation 5) . ... 

Metal ions will not catalyze the decarboxylation of monocarboxylic acids, presumably because metal ion complexation with the ground state is more stable than complexation with the transition state. A reversal of this argument indicates... 

A variety of chromium(III) and cobalt(III) oligomers can be prepared by oxidation of an aqueous solution of the appropriate divalent metal-ion complex with oxidants such as 02 and Tl3 +. The... 

Metal ion complexes with 1,8-naphthyridine could be conceived as possessing any or all of the following structures (a, b, or c) ... 

A similar situation arises when the metal-ion-catalysed base hydrolyses of aminoacids and peptides are studied. Such hydrolyses contrast with the base hydrolyses of simple esters, which are not catalysed by metal ions. Again, metal ion complexes with the aminoacid esters or the peptides are involved in the catalyses. The presence of the metal ion increases the electron-withdrawing power of the carbonyl group and helps attack by the hydroxide ion, leading to efficient hydrolysis. 

Metal Ions Complexation with Humic Materials in... 

Crown ethers continue to be one of the most useful parts of supramolecular chemistry/91 From the beginning computations of metal ions complexes with synthetic ionophores/101 which have been aptly reviewed/111 emphasized the importance of including explicitly solvation in free energy calculations, also with ab initio calculations on calixarene complexes/121 Molecular dynamics simulations of 18-crown-6 ether complexes in aqueous solutions predict too low affinities, but at least correctly reproduce the sequence trend K+ > Rb+ > Cs+ > Na+. However, only the selection of K+ over Rb+ and Cs+ is ascribed to the cation size relative to that of the crown cavity, whereas K+ appears in these calculations to be selected over Na+ as consequence of the greater free energy penalty involved in displacing water molecules ftomNa/1131... 

Quantitative estimation of the stability constants for metal ion complexation with 1-substituted tetrazoles has been performed <2005CEJ6246>. It was demonstrated that tetrazole nucleoside 277 shows a low tendency to form stable complexes with ions Ag(l) and Hg(ll) comparing with imidazoles and 1,2,4-triazoles. Only Ag+ is able to form a 1 1 complex with compound 277 (log0.86), and no coordination of Hg2+ to 277 can be detected. 

Figure 11. Proposed scheme and rate equations for the reaction of phosphosulfate-metal-ion complex with base or nucleophile. Several variations may be conceivable such as to include a substrate-metalion-reagent ternary complex.

Macrocycle obtained by the condensation of phenol rings with formaldehyde and amenable to substitution both on the phenolic functions and on the para positions of the phenol rings Macropolycyclic ligand forming a cage Metal ion complex with a cryptand... 

In contrast to the behavior of 68, an efficient chemosensor for Mg2+,123 compound 107 has been shown to be a potential chemosensor for Hg2+.157 Ligand 107 forms stable 1 1 complexes with Hg 2+, Cu2+, Cd2+, Zn2+, Ni2+, and Mg2+ in methanol-water (1 1 vol vol). Much lower association constants (log Ka < 2.5) are observed with the other alkaline earth ions, whereas no complexation is detected (log < 1.5) for alkali metal ions. Complexes with Cu2+ and Ni2+ are not luminescent as... 

According to the Nernst equation, the positive shift of Lred ( red) of PQ due to the complex formation with M" is determined by the difference in the binding constants between metal ion complexes with PQ (Ko ) and PQ (iifred) as given by Eq. 8, which is rewritten by Eq. 9 (94). The 1 1 complex formation of... 

Metal ion complexes with ammonia are called ammines. At room temperature, ammonia is a gas, but liquid ammonia (b.p. -33 °C) is relatively easy to handle and is an excellent solvent and reagent (equation 10) ... 

The results of studies for complexes formed between polyammonium macrocycles and transition metal complex anions indicate that cation anion electrostatic attraction is a crucial factor in complexation reactions and serves to regulate the stoichiometry of the complexes formed. Hydrogenbonding, size, and conformational factors also play major roles. Anions can be incorporated in or out of the ring. Two illustrative examples are metal ion complexes with the octaprotonated macrocycle Hg[30]aneNio (46). In the complex with Co(CN)6 , the anion hes outside the macrocycle. The PdCLi complex is a true inclusion situation, however, in which the PdCU is situated along the minor axis of the macrocychc cavity, and the Cl atoms are out of the frame, forming strong hydrogen bonds with the polyammonium... 

Bjerrum, J., Schwarzenbach, G., and Sillen, L.G. Stability Constants of Metal-Ion Complexes, with Solubility Products of Inorganic Substances." 131 p. The Chem. Soc., No. 17, London, 1958. 

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