MOH groups

In reaction (18), one of the unshared pairs of electrons on the oxygen atom of the MOH group has accepted a proton, and so MOH can act as a base without actually releasing hydroxide ion. 

The structures of the oxides and hydroxides are arranged so that the number of oxygen ions adjacent to each metal ion—the coordination number (v)—varies from 2 to 8 (89, 90, 91). In Equation 12 the empirical constant a for each v is related to the coulombic attractive energy between the group of oxygen ions and the proton of the MOH group. 

In our original calculations (,9) we found the AlOH bond of HAIOH to be linear but with a relatively small force constant for bending. In the calculations on the other hydroxyhydrldes the MOH group was restricted to be linear. In very recent work,... 

Figure I. A structural comparison between the Mos7V6 -type cluster 2 (upper halO and the Moj6 -type cluster 1 (lower halO along perpendicular views with a highlighted M017 building group ( Mo i units hatched, Moh groups dark gray, V units hatched).

The ionization of surface MOH groups is characterized by the local equilibria (7.1) and (7.2). Under fixed acidity conditions, the net surface charge density ao is... 

The MOH species which is present on the surface of the metal oxide is amphoteric in nature and has a tendency to attract both acidic and basic species. These active groups interact with either OH or groups of the analyte solution. These surface interactions lead to a protonation or deprotonation of the MOH groups and develop a surface charge which is equal to the pH of the analyte solution. The ion-sensitive CuO film thus contains surface sites which can specifically interact with H ions (hydrogenate) after interaction with an electrolyte solution. The CuO surface charge and surface potential depend on the protonation or deprotonation of these sites which is equal to the pH of electrolyte solution. 

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