Nitrate, formation constants with

It has been demonstrated spectroscopically that Ce(IV) - and V(V) perchlorates and Ce(IV) nitrate form complexes with alcohols of composition [ROH Ce(IV)] and [ROH V(OH)3]. The agreement between the determined formation constant and the Michaelis-Menten constant for Ce(IV) oxidation is good evidence for the role of these complexes in the oxidation process. The oxidations by Co(iri) and V(V) perchlorates have kinetics... 

The behavior of metal ions in reversed micelles may be more interesting, since the reversed micelle provides less solvated metal ions in its core (Sunamoto and Hamada, 1978). Through kinetic studies on the hydrolysis of the p-nitrophenyl ester of norleucine in reversed micelles of Aerosol OT and CC14 which solubilize aqueous cupric nitrate, Sunamoto et al. (1978) observed the formation of naked copper(II) ion this easily formed a complex with the substrate ester (formation constant kc = 108—109). The complexed substrate was rapidly hydrolyzed by free water molecules acting as effective nucleophiles. 

Using a glassy carbon electrode modified with a mercury film, Weber et al. [66] measured the association and dissociation rate constants for the complex formed between Pb + and the 18-crown-6 ether. It was found that Pb + forms a complex with 18-crown-6 with a stoichiometiy of 1 1 in both nitrate and perchlorate media. The formation constant, for the nitrate and perchlorate systems are (3.82 0.89) X 10 and (5.92 1.97) x lO mol Ls , respectively. The dissociation rate constants, are (2.83 0.66) x 10 with nitrate and (2.64 0.88) x 10 s with perchlorate as counter ion. In addition, the binding of Pb + with benzo-18-crown-6 embedded in a polymerized ciystalline colloidal array hydrogel has been also analyzed [67]. 

With silver nitrate, colourless sheets could be precipitated by the addition of anhydrous ether to an aziridine solution. It was noticed that on standing for a few days in aqueous solution the salt decomposed and deposited metallic silver. The formation constants in aqueous solution were determined at 16.5 °C (/ = 1.0 M NaN03) log 8i = 2.40, log /S2 = 5.40.54... 

The first metal complex of quinuclidine (2) was reported in 1966.58 Ag(quinuclidine)2N03 was isolated as a white solid after reaction of quinuclidine and silver nitrate in acetonitrile for several days. The formation constants were determined in DMSO (Table 11). The complex melted with decomposition at 158 °C. 

Reaction of disodium tartrate with silver nitrate at pH S.6 was followed by the change in the absorption spectrum at 216-250 nm. Two complex ions were proposed, Ag(C4H4Oe)- and Ag(C4H406)2, with formation constants log j8i = 2.29 and log / 2 = 4.21 respectively.266... 

Figure 3. Structures of the polyhorates with the log formation constants for 0.05M boric acid at 25°C in 0.15M potassium nitrate...

Figure 4. Reactions of borate with mannitol with the log formation constants of the complexes at 25°C and 0.15M in potassium nitrate...

Collection of metal complexes of the analytes on suitable adsorbing materials is often employed as an enrichment step in combination with flame methods. In a procedure proposed by Solyak et al. [20], five metals [Co(II), Cu(II), Cr(III), Fe(III), and Pb(II)] were complexed with calmagite 3-hydroxy-4-[(6-hydroxy-m-tolyl)azo]-naphthalenesulfonic acid and subsequently collected on a soluble cellulose nitrate membrane filter. In this way an effective separation from alkaline and alkaline earth metals was achieved, based on the differences in their complex formation constants and those of the transition elements. The experimental parameters were optimized for the quantitative recovery of the elements. After hot dissolution of the filter with HNO3, the analytes were determined by FAAS. Minimum detectable concentrations ranged from 0.06 pg l-1 for Cu to 2.5 pg l-1 for Cr. 

Hexavalent. Nitrate complexation with actinide ions is very weak, and the determination of the formation constants for aqueous nitrate solution species is extremely difficult. Under aqueous conditions with high nitric acid concentrations, complexes of the form An02(N03)(H20)x+, An02(N03)2(H20)2, and An02(N03)3 (An = U, Np, Pu) are likely to be present. Solids of the anionic trisnitrato complex have been isolated for U and Np however, minimal structural data have been obtained. Solid uranyl nitrate, U02(N03)2-xH20, is obtained as the orthorhombic hexahydrate from dilute nitric acid solutions and as the trihydrate from concentrated acid. The Np analog can be precipitated from a mixed aqneons HNO3 and MeCN solntion by the addition of 18-crown-6. Multiple structural determinations have been made for the hexavalent uranium nitrate complexes, and all show the common formula unit of... 

Alkali metal picrates have been used to measure formation constants for crown ethers in solution, but the selectivity of benzo crown ethers for metal picrates, relative to the analogous chlorides, nitrates, perchlorates, and thiocyanates, may vary significantly. Apparently, it—it interactions between the picrate ions and the aromatic ring(s) on the crown are responsible for the difference. The importance of the picrate effect rises as the number of benzo groups in the crown ether is increased, and it varies with their location in the macrocycle. The dependence of the picrate NMR chemical shift on the metal cation and/or macrocycle identity has been used to study picrate-crown ether 7r-stacking in large crown ether (18, 21, and 24-membered) complexes. 

Weak complexes form between vanadate and phosphate, 9,99 pyrophosphate,59 arsenate,59 and chromate.106 The formation constant for the simple phosphovanadate is about 20 M 1." Structural characterization has been reported for interesting cluster structures of vanadium with organophosphonates107 and with sulfate.108 Divanadium(V) complexes with either monodentate or bidentate nitrate (N03 ) groups have been reported.109... 

Calcium ion forms a weak 1 1 complex with nitrate ion with a formation constant of 2.0. What would be the equilibrium concentrations of Ca " and Ca(N03) in a solution prepared by adding 10 mL each of 0.010 M CaCl2 and... 

SOL] Solovkin, A. S., Determination of hydrolysis constants and of formation constants of Zr with nitrate- and chloride- ions by extraction methods, Russ. J. Inorg. Chem., 2, (1957), 216-236. Cited on pages 117, 153, 197, 198, 199, 252, 256, 257. 

The equilibrium constants and SIT coefficients selected in this table refer to a strict ion interaction approach where the effect of chloride or nitrate complexation is included in the interaction coefficients. Therefore these values must not be combined with the formation constants of chloride and nitrate complexes discussed in Sections VIII.2.2.1 and X. 1.3.3. 

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