Coordination compounds Coulomb interactions

There is no uniformity in the effect of pH on the dissociation constants of the NAD compounds. The pronounced decrease of Xe.nad for liver alcohol dehydrogenase from pH 6.0 to pH 10.0 was attributed to ionization of a water molecule coordinated to the active center zinc atom and Coulombic interaction with the nicotinamide N-1 (64)- The absence of a similar pH effect with the other dehydrogenases studied so far is understandable on this basis. Structural studies of the compounds of liver alcohol dehydrogenase with ADPR and 1 10-phenanthroline, competitive... 

Coulomb s law E = 2.31 X 10 QiQzM, where E is the energy of interaction between a pair of ions, expressed in joules r is the distance between the ion centers in nm and Qi and Q2 are the numerical ion charges. (13.1) Counter ions anions or cations that balance the charge on the complex ion in a coordination compound. (19.3) Covalent bonding a type of bonding in which electrons are shared by atoms. (2.7 13.1)... 

Ion conductors are usually compounds in which the atoms are bonded together with an ionic bond. Textbooks on ion conduction do not spend much time on bonding and for ionically conducting solids the classical electrostatic Coulomb interaction suffices. However, there also exist covalent layered lattices, which admit intercalation of ions between the covalent layers, and these lattices can conduct electrons as well as interstitial ions. Good ion conductors have ions that in their bond with the other atoms in the lattice have no strong preference for one particular coordination number, but balance between two values. This lowers the activation barrier of the ion path through the lattice and results in a higher ionic conduction. 

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