Zur Kenntnis der Säuren-Basen-Theorie von Ussanowitsch

Gehlen, Heinz

doi:10.1515/zpch-1954-0108

Cited by 6 publications

(10 citation statements)

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“…If the distance is small, the acidic strength is high and most of the associates are dissociated even at comparatively low temperatures, the distance being a direct measure of pK ass or pK diss , that is, of pK a or pK b . In the same way as NH 4 is a weaker acid than HOAc, (Ag . i S' Cl ) is a weaker (generalized) acid than (Ag .…”

Section: Internal Acid ± Base Equilibria In Solidsmentioning

confidence: 96%

“…[25] Making use of the isomorphy of the relations with regard to the complex acidic and basic centers in water (Figure 2 left), we recognize that similarly the distance of acidic or basic levels to the fundamental m Å o H and m Å o jHj À levels yield the pK a and pK b values, respectively. To give an example: the levels in the left part of Figure 2 correspond to the acid ± base pairs HOAc/OAc À (Ac CH 3 CO) and NH 4 /NH 3 and represent the normalized standard potential of the protons in HOAc or NH 4 . Flat levels correspond to strong acids, deep levels to weak acids and a mid gap position means pronounced amphoterism.…”

Section: Internal Acid ± Base Equilibria In Solidsmentioning

confidence: 99%

“…4) Finally, the thermodynamic analysis shows that it is most straightforward for ionic crystals to restrict acid ± base properties to purely ionic exchange reactions, not necessarily of the protons, that is, to Brùnsted-like acid ± base effects. Thus, in the terminology of references [3,4] we refer to ionotropic reactions as counterpart to the redox reactions in which only electronic carriers are exchanged. In those cases in which the reaction with a certain species gives rise to both ion and electron exchange, it proves to be most straightforward to useÐfor the purely heteropolar systemsÐterms such as redox acids or redox bases (consider, for example, the interaction of hydrogen with a solid generating both H and e À ) to characterize this double function, rather than to extend and generalize the terms acids and bases to species taking part in the electronic transfer process as most explicitly done by Ussanowitsch.…”

Section: Introductionmentioning

confidence: 99%

“…[13] Similarly we can write Equation (4) m Å OH À m Å o OHÀ À pOH (4) [14,15] we get Equation (5) (see also Scheme 1). s corresponds to a normalized standard affinity, D w G o .)…”

Section: Introductionmentioning

confidence: 99%

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Acid-Base Centers and Acid-Base Scales in Ionic Solids

Maier¹

2001

Chem. Eur. J.

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For the case of ionic crystals it is shown to be most straightforward and consistent to define acidity/basicity by the (electro-)chemical potential of the respective ion, in a similar fashion to the way that the Fermi level (i.e.. electrochemical potential of the electron) characterizes the redox state. The isomorphy is explicitly expressed by using the energy-level diagrams introduced for electrons in semiconductor physics. Without having to make further assumptions it is possible 1) to compare acidity/basicity between different solids, 2) to link internal and surface acidity/basicity, and 3) to establish acidity/basicity scales for ionic solids. The point defects are revealed to be the natural acidic and basic elementary centers, and associates between them to be the internal acids/bases exchanging these elementary centers. Even though acidity/basicity is an overall property of the solid, the number of point defects (if dilute) directly represents these properties in the same way as H+ or OH- accomplish this for aqueous solutions.

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Section: Internal Acid ± Base Equilibria In Solidsmentioning

confidence: 96%

Section: Internal Acid ± Base Equilibria In Solidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…[13] Similarly we can write Equation (4) m Å OH À m Å o OHÀ À pOH (4) [14,15] we get Equation (5) (see also Scheme 1). s corresponds to a normalized standard affinity, D w G o .)…”

Section: Introductionmentioning

confidence: 99%

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Acid-Base Centers and Acid-Base Scales in Ionic Solids

Maier¹

2001

Chem. Eur. J.

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“…One (30), may also contribute to the former. Moreover, the products of these two processes could simultaneously serve as osmolytes Proc.…”

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confidence: 99%

In vivo 23Na and 31P NMR measurement of a tonoplast Na+/H+ exchange process and its characteristics in two barley cultivars.

Fan

Higashi

Norlyn

et al. 1989

Proc. Natl. Acad. Sci. U.S.A.

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A Na+ uptake-associated vacuolar alkalinization was observed in roots of two barley cultivars (Arivat and the more salt-tolerant California Mariout) by using 23Na and 31p in vivo NMR spectroscopy. A NaCi uptake-associated broadening was also noted for both vacuolar Pi and intracellular Na NMR peaks, consistent with NaI uptake into the same compartment as the vacuolar Pi. A close coupling of Na' with H' transport (presumably the Na+/H' antiport) in vivo was evidenced by qualitative and quantitative correlations between Na+ accumulation and vacuolar alkalinization for both cultivars. Prolongation of the low NaCl pretreatment (30 mM) increased the activity of the putative antiport in Arivat but reduced it in California Mariout. This putative antiport also showed a dependence on NaCl concentration for California Mariout but not for Arivat. No cytoplasmic acidification accompanied the antiporter activity for either cultivar. The response of adenosine phosphates indicated that ATP utilization exceeded the capacity for ATP synthesis in Arivat, but the two processes seemed balanced in California Mariout. These comparisons provide clues to the role of the tonoplast Na'/H' antiport and compensatory cytoplasmic adjustments including pH, osmolytes, and energy phosphates in governing the different salt tolerance of the two cultivars.Though not halophytes, some barley (Hordeum vulgare L.) cultivars are more salt tolerant than are many other crop plants (1-3). Vacuolar Na+ accumulation, part of the response to salt stress (4, 5), is probably mediated through a Na+/H+ antiport that uses the pH gradient between the vacuole and cytoplasm established by means of a H+-ATPase (6). Evidence consistent with the scheme, including the H+-ATPase and Na+/H+ antiporter activities, has been obtained from isolated tonoplast vesicles of barley roots (7-10) and other plant tissues (11-13). In addition, the barley Na+/H+ antiport was shown in isolated tonoplast vesicles to be activated under short-and longer-term NaCl pretreatment (9,14). The relevance of these in vitro findings for plant responses to salt stress needs to be clarified by observation of this process in vivo.One inevitable compensatory consequence of the Na+/H+ exchange process at the tonoplast is at least a transient build-up of H+ in the cytoplasm, which needs to be dissipated for normal functioning of the cytoplasm. The cytoplasm also requires separate osmotic adjustment, Na+ being unsuitable for osmoregulation there (4). In both cases, the "energy" metabolism of the plant will likely be impacted and represent a limiting factor for salinity responses (15, 16). As with the Na+/H+ antiport itself, coordination among compartments is a key feature of the biochemistry accompanying the antiporter activity, hence the need for in vivo experimental approaches that maintain tissue integrity.We have applied the in vivo NMR approach to the saltsensitive barley cultivar Arivat and the more tolerant California Mariout (CM). The advantages of NMR as an noninvasive tool are well docum...

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The Usanovich definition of acids and bases – A forgotten pioneer of the donor−acceptor principle

Reiners

Marniok

Müller

2020

Chemkon

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Ein nahezu in Vergessenheit geratenes Säure‐Base‐Konzept ist die Ende der 1930er‐Jahre, etwa zeitgleich mit dem ungleich bekannteren Lewis‐Konzept, publizierte Definition des sowjetischen Chemikers Michail Ussanowitsch. Sein sehr weit gefasstes Konzept zeigte die Parallelen zwischen Protonen‐ und Elektronenübertragungen bei einer Vielzahl chemischer Reaktionen auf, lange bevor der Begriff des Donator‐Akzeptor‐Prinzips eine prominente Rolle in der Chemiedidaktik erlangte. In diesem Artikel wird nicht nur das Ussanowitsch‐Konzept an sich und seine Verbreitung dargestellt, sondern auch eine Möglichkeit, dieses als historisches Fallbeispiel zur Vermittlung der „Natur der Naturwissenschaften“ (NOS) zu verwenden. Dazu werden auch Ergebnisse einer entsprechenden Studie mit Lehramtsstudierenden vorgestellt.

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Zur Kenntnis der Säuren-Basen-Theorie von Ussanowitsch

Cited by 6 publications

References 0 publications

Acid-Base Centers and Acid-Base Scales in Ionic Solids

Acid-Base Centers and Acid-Base Scales in Ionic Solids

In vivo 23Na and 31P NMR measurement of a tonoplast Na+/H+ exchange process and its characteristics in two barley cultivars.

The Usanovich definition of acids and bases – A forgotten pioneer of the donor−acceptor principle

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