New equation for calculating total interaction energy in one noncyclic ABC triad and new insights into cooperativity of noncovalent bonds

Abstract

In this work, a new equation consist of A⋅⋅⋅B, B⋅⋅⋅C, A⋅⋅⋅BC, and AB⋅⋅⋅C interactions is proposed for calculating the total interaction energy of noncyclic ABC triads. New equations are also proposed for calculating the changes in values of A⋅⋅⋅B and B⋅⋅⋅C interactions on the formation of triad from the corresponding dyads. The advantages of equations proposed here in comparison with many-body interaction energy approach are discussed. All proposed equations were tested in F MLi⋅⋅⋅NCH⋅⋅⋅HLH and F MLi⋅⋅⋅HLH⋅⋅⋅HCN (M = C, Si; L = Be, Mg) as well as H N⋅⋅⋅XY⋅⋅⋅HF (X, Y = F, Cl, Br) noncyclic A⋅⋅⋅B⋅⋅⋅C triads. The data show that the total cooperativity of triad correlates well with the sum of the changes in values of A⋅⋅⋅B and B⋅⋅⋅C interactions calculated through new equations proposed here. © 2016 Wiley Periodicals, Inc.

The comparison of structure, nature of bond, and electronic transitions in [M(η5‐Cp)(η5‐C60Me5)] (M = Fe2+, Ru2+, Os2+) hybrids and corresponding metallocenes; a theoretical study

“…We know that in all triad systems, whenever there is a cooperativity between two bonds the A-BA 0 and AB-A 0 interactions will be stronger than A-B and B-A 0 ones. 52,53 Thus the present data clearly show the strong anticooperativity of two metal-ligand bonds in all complexes. 52 This is in contrast to our results for different ABA 0 systems, where the central anion had interaction with two neutral metal complexes.…”

“…52,53 Thus the present data clearly show the strong anticooperativity of two metal-ligand bonds in all complexes. 52 This is in contrast to our results for different ABA 0 systems, where the central anion had interaction with two neutral metal complexes. 53 In our opinion, for all systems having two anionic ligands interacting with a central metal cation, we can probably expect the existence of anticooperativity of bonds.…”

“…It should be note that the Equation (5) has been initially proposed for non-covalent interactions in triad systems, 52 but the previous 53 and the present calculations clearly show that it is accurately applicable for metal complexes having three A, A 0 , and B (or A, B, and C) components.…”

“…On the other hand, The total IE for each complex was calculated using two different Equations ( 5) and (6). 52,53…”

A computational study on the nature, strength and cooperativity of bonds in [M(η5–C60Me5)(CO)n] and [M(η5–Cp)(CO)n] (n = 3, M = Mn(i), Tc(i), Re(i); n = 2, M = Co(i), Rh(i), Ir(i)) complexes

“…The total interaction energy for each complex was calculated using two different eqn ( 5) and ( 6): 42,43…”