Free electrostatic binding

In the ionic model, the formation of a complex ion from the free central ion and the ligands is combined with a stabilization by the electrostatic binding energy Edass- The resulting state corresponds to the electronic ground state of the complex. From the crystal-field theory, however. 

Faulkner and coworkers have used a ternary complex formation approach to bring about mixed Eu -Tb complexes. This work is based on kinetically stable cyclen D03A type frameworks and initially focused on the self-assembly of mononuclear Tb and Eu complexes where the charge neutral Eu complex contained a free carboxylic acid on the periphery of the complex (Figure 6), free to bind to the cationic Tb through electrostatic interactions. 

Poly(vinyl-4-pyridine) has the catalytic capacity to accelerate the solvolysis of 2,4-dinitrophenyl acetate but the rate constant of the reaction increases as the fraction of neutral pyridine residues increases. In fact, both free and charged species are probably needed for catalysis the charged residues providing electrostatic binding. 

In case of the rigid lock-and-key type receptor forming five hydrogen bonds plus two extended electrostatic attractions (Fig. 3a), one mismatched hydrogen bond will result in only a small reduction in overall binding free energy 4.18-8.36 kJ mol (1-2 kcal mol ) out of... 

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