Size and Hydration of Inorganic Macroions from Viscosity and Density Measurements

Abstract

Size and Hydration of Inorganic Ions 1567 to resist removal as carbonyl by a carbon monoxide stream at 80°, while the rest of the nickel is easily so removed.10 It also has been shown that it is the larger particles of nickel which may be selectively removed in this way.11 It appears, then, that the larger over-all nickel concentrations give, on the whole, larger particles, and that these particles more readily form partial or true solid solutions with copper. The nickel in those samples with low over-all nickel concentrations is, on the other hand, less likely to form solid solutions with copper because of the diminished accessibility to copper in the preparative stage.These conclusions are supported by the results on samples (4) and ( 5). The preparation method for these samples would suggest that mechanical mixtures would be the only result. This is obviously the case. It may, in fact, be stated that no appreciable amount of the nickel is diluted with copper in these two samples.Sample (6) was studied for the express purpose of determining whether the procedure used by Best (10) G.

In situ measurement of the Preyssler polyoxometalate morphology upon electrochemical reduction: A redox system with Born electrostatic ion solvation behavior

“…1a and c, respectively), we can relate their average R g , which are obtained as 3.93(3) and 2.93(2) Å, respectively, from the data in Table 3, to their average crystallographic radii, R, by R ¼ ffiffi 5 3 q R g [82]. For the Keggin systems, the R calculated in this manner is 5.1 Å, which is within the range of literature values (5.0-5.8 Å) [6,7,12,79,[83][84][85][86][87][88]. For the Lindqvist hexatungstates, the calculated R of 3.8 Å is consistent with the 4.0 Å envelope radius determined as the average distance between the central oxygen atom to the 6 terminal-oxo atoms for the structure illustrated in Fig.…”

“…(2) to the [MPA] nÀ15 system stands in contrast to the phenomenological effects observed in electrochemical studies of Keggin, a-[X n+ M 12 O 40 ] nÀ8 , POMs. Although these have rigid structures of indistinguishable radii, [13,49,83,84,88] contrary to expectation, the series of clusters exhibits non-Bornian dependencies between DE o 1 and 1/r [91]. It has been suggested that extrinsic, short-range inter-molecular contacts between Keggin anions and solvent molecules are the complicating sources of the deviant behavior [51,94] [98,99].…”

Ionic-strength dependence of electron-transfer reactions of Keggin heteropolytungstates: Mechanistic probes of O2 activation in water

“…This analysis of the nature of Keggin heteropolytungstates in water is supported by the results of diffusion-rate [10,23], and density [24] measurements, which, through application of the Stokes-Einstein equation [25], argue that the effective hydrodynamic radii of 3-, 4-, 5-and 6-Keggin anions are equal to their crystallographic radii. This means that, on average, these Keggin anions are each solvated by no greater than one water molecule.…”

Effects of Organic Solvents and Salts on the Isomerization Reaction (β→α) of Keggin-type 12-Molybdophosphate Anion

“…[39][40][41] It has already been reported that the size of Keggin anions is almost the same, even if the hetero anions and addenda atoms are changed. 1,[42][43][44][45] Because the total charge of 12-molybdophosphate or 12-molybdoarsenate is -3, whereas that of 12-molybdosilicate or 12-molybdogermanate is -4, the 12-molybdosilicate and 12-molybdogermanate form as predominant species, even in acidic aqueous solutions. Conversely, in acidic aqueous Mo(VI)-P(V) systems, the 12-molybdophosphate anion is not the primary species, although only PMo12 forms in acidic aqueous-organic mixed media.…”