Conductometric studies

Euler was the first to suggest the presence of nitronium ions in mixed acids (Ref 12), This view was later supported by the conductometric studies of Walden (Ref 14). Titov (Ref 28) reinterpreted Hantzsch s data and suggested that the simplest way to explain them was ... 

These early results have since been confirmed and extended by a vast and still growing body of research. All of the contemporary spectroscopic techniques (ir, uv, visible, nmr, esr) have been brought to bear on the problem, and further confirmation has come from cryoscopic and conductometric studies. The early confusion that resulted from the coexistence of both donor-acceptor or non-covalently-bonded complexes) has been clarified. This research has been extensively reviewed10,13-15 and will not be detailed here. 

The kinetics of polymerization and conductometric studies of barium polystyrene with one active end-group per chain were reported by De Groof et al. 79,80). Formation of an unconventional anionic species, Ba2 +, (CH(Ph)CH2—)j, had to be postulated to account for the results. The existence of such a species is supported by the recent study of the kinetics of polymerization of lithium polystyrene performed in the presence of barium polystyrene endowed with two active endgroups 78). The polymerization of the lithium salt is retarded by the presence of the barium salt, and the retardation is accounted for by the formation of the inert aggregated anions,... 

Evans, G. G., J. K, Kennedy jr., and F. P. Del Greco Conductometric Study of the Reactions between Metal Halides and Lithium Aluminium Hydride, I. Aluminium Chloride. J. Inorg. Nucl. Chem. 4, 40 (1957). 

Abstract This chapter discusses the effect of ultrasound propagation in water and aqueous solutions, in the atmosphere of inert and reactive gases. Sonochemical studies of aqueous solutions of divalent and trivalent metal ions and their salts have been reviewed and the precipitation behaviour of hydroxides of metal ions has been discussed. Synthesis of nanoparticles of many metals using ultrasound and in aqueous solutions has also been discussed briefly. Besides, the nephelometric and conductometric studies of sonicated solutions of these metal ions have been reported. 

Hissung A, von Sonntag C (1978) Radiolysis of cytosine, 5-methylcytosine and 2 -deoxycytidine in deoxygenated aqueous solution. A pulse spectroscopic and pulse conductometric study of the OH adduct. Z Naturforsch 33b 321—328... 

On the basis of conductometric studies and taking into account the catalytic action of nitrogen dioxide in the nitration Klemenc Mid Scholler [34] suggested... 

Further conductometric studies of nitric acid by Medard [48] and later Dalmon [49] have shown that on adding water to the anhydrous acid, conductivity falls... 

The use of DMSO in recent studies has been largely upon the premise that the problem of base association would be avoided. Some doubt as to the validity of this assumption arises when the results of a conductometric study are considered (Exner and Steiner, 1974). Ion-pairing constants for lithium, sodium, potassium and cesium t-butoxide in DMSO have been evaluated as 108, 106, 270 and 200 M-1 respectively. Not only do these results suggest that there is base association in DMSO but they also imply that base-catalysed reactions involving alkali metal alkoxides in DMSO should be affected by the nature of the cation. If these conclusions are valid and if the possible involvement of the dimsyl anion in these reactions is also taken into consideration, then the choice of DMSO to remove the problem of base association can be a poor one, especially if the base is a lithium or sodium salt of a hindered alkoxide. It is far better to avoid association effects by the use of crown ethers (Bartsch et al., 1973, 1974, 1975). On the other hand, the use of lithium and potassium t-butoxide in DMSO solvent might aid in distinguishing reactivities of free ions and of ion pairs in certain processes. 

The behavior of acids and bases in NMA has been examined by several groups of researchers. Values for the pKa of acids determined in these potentiometric and conductometric studies are summarized in Table VU-1. The measurements have not been carried out at any single temperature and one extensive study reports values... 

Fig. 2.16. Scheme of the device used for the conductometrical study of foam films [106] 1 - a vessel... 

Water-TMS Mixtures. Conductometric studies on Li, Na, and K chlorides and hydrochloric acid in water-TMS have shown association constants higher than the Fuoss equation predicts in these mixtures too. In the case of HCl, KA values equal to 26 5, 51 d= 9, and 76 4 corresponded to dielectric constant values of 61.42, 54.69, and 47.34, respectively. On the contrary, KA values for the same systems calculated on the basis of the Fuoss equation using the reasonable value of 4 A for the... 

Conductometric Study of Hydrophobic Properties of Tris(l,10-phenanthroline) and Tris(2,2 -bipyridine) Complexes. 

Michaels AS, Miekka RG. Polycation-polyanion complexes preparation and properties of poly(vinylbenzyltrimethylammonium) poly(styrenesulfonate). J Phys Chem 1961 65(10) 1765-1773(a). Micheals AS, Mir I, Schneider NS. A conductometric study of polycation-polyanion reactions in dilute aqueous solution. J Phys Chem 1965 69(10) 1447-1455(b). 

A.S. Michaels and R.G. Miekka, Polycation-polyanion complexes Preparation and properties of poly(vinylbenzyltrimethylammonium) and poly(styrenesulfonate), J. Phys. Chem., 1961, 65, 1765-1773 A.S. Michaels, L. Mir and N.S. Schneider, A conductometric study of polyaction-polyanion reactions in dilute solution, J. Phys. Chem., 1965, 69, 1447-1455 S.J. Reid, J. Th. Overbeek, W. Vieth and S.M. Fleming, Membrane potential differences with the polyelectrolyte complex - poly(vinyltrimethy-lammonium)-poly(styrenesulfonate), J. Colloid Polym. Sci., 1968, 26, 222-229, O. Yano and Y. Wada, Effect of sorbed water on dielectric and mechanical properties nf nnlvinn enmnlex../ Ann Polvm. Sci.. 1980. 25. 1723-1735. 

C. Burger-Guerrisi and C. Tondre, Conductometric study of the interaction of 1 1 electrolytes with nonionic surfactant having short polyoxyethylated chains Methanolic solutions of H- and F-alkylated surfactants and oil/water microemulsions, J. Colloid Interface Sci., 1987, 116, 100. 

The equilibrium constants for reactions 17, 18, and 19 are Kl7, Kl8, and K19, respectively, and these equilibrium constants differ greatly. For tetraphen-ylethene [(C6H5)2C = C(C6H5)2], which will be denoted by T, all three constants are known. They were determined from the results of spectrophotometric studies (7) of the system T,T ,Na+ and T2 ,2Na+ in THF, in conjunction with the conductometric studies that led to the values of Kdisu and Kdiss,2 for reactions 20 and 21, respectively ... 

Hence, plots of 1/Kap versus ([T][totalT2 ]) 1/4, shown in Figure 4, provide the values of K19 and Kdiss 2 for the three temperatures investigated. Direct conductometric studies confirmed the value of Kdiss 2 derived from Figure 4, and they also provided the value of x. Because K19/K18 = s 2,... 

This is a report on a careful conductometric study. Sets of data were obtained for 5°C intervals for temperatures between 0 and 45°C. The sets of equivalent conductivities are reported for specific concentrations from 0.0002 to 0.003 M, and have the appearance... 

A conductometric study of CdCU solutions in HOAC-H2O indicates association into ion pairs such as [Cd2Cl2]. Measurements on Me0H-H20 solutions of CdCl2-KI indicate formation of the CdlJ ion. Studies of MX2 dissociation in DMSO (M = Cd or Hg X = Cl, Br, I or SCN) show, in the case of Hg, the same order of stability as found in aqueous solution (I > Br > Cl > SCN), while a different order of stability is found for the Cd complexes. 

J. H. Exner, E. C. Steiner, Solvation and ion pairing of alkali-metal alkoxides in dimethyl sulfoxide. Conductometric studies, J. Am. Chem. Soc., 1974, 96, 1782-1787. 

Because of the possibility of ion association and charge transfer the use of conductometric titration is suggested. Preliminary unpublished conductometric studies by the authors on the reaction between bromophenol blue and quaternary ammonium and arsonium salts failed, within the sensitivity of the instrument used, to detect any conductivity changes. The reaction is, however, accompanied by metachromasia and can be followed spectrophotometrically, showing again the complementary nature of the physical methods available. 

R.I. Gelb and J.S. Alper, Anomalous conductance in electrolyte solutions A potentiometric and conductometric study of the dissociation of moderately strong acids. Anal. Chem. 72 (2000), pp. 1322-1327. 

ArgueUes-Monal W., Cabrera G., Peniche C., Rinaudo M., Conductometric study of the inter-polyelectrolyte reaction between chitosan and poly(galacturonic add). Polymer, 41,2000, 2373—2378. 

W. A. Alves, Vib. Spectrosc. 2007,44,197-200. Vibrational spectroscopic and conductometric studies of lithium battery electrolyte solutions. 

M. Hojo, T. Ueda, H. Hamada, Z. Chen, S. Umetani, J. Mol. Liq. 2009, 145, 24-32. Conductometric studies on higher ion-aggregation from lithium fluoroalkanoates in propylene carbonate and AdV-dimethylformamide. 

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