New insights into the intrinsic cooperativity of intermolecular orintramolecular bonds

There are some well-known methodologies for evaluating the cooperativity of intermolecularnoncovalent bonds [۱,۲]. However, in this work, we report our methodology for study on theintrinsic cooperativity of both intermolecular noncovalent bonds and intramolecular metal–ligandbonds. Indeed, we improve and extend the methodology proposed in our research group [۳] andshow that the quantitative evaluation of the impact of chemical bonds on the strength of each otheris not restricted to the intermolecular noncovalent bonds. New equations are proved for calculatingthe total stabilization and interaction energies as well as the cooperative energies of bonds in anysystem that can be considered as three fragments and two chemical bonds. We report also thecalculation of the cooperativity of bonds in some metal complexes of the type LML′, where L andL′ represent a single ligand or a group of ligands. The results show that both the M−L and M−L′bonds will strengthen or weaken depending on the degree of cooperativity or anticooperativity ofbonds. Thus, the rational design of a system with a very weak or a very strong bond is possible,where we know the type and degree of cooperatvity of bonds.

کلیدواژه ها:

Theoretical study ، Cooperativity of bonds ، Noncovalent bond ، Metal−ligand bonds