The ability of Ex²Box⁴⁺ to interact with guests containing π‐electron‐rich and π‐electron‐poor moieties

Abstract

The ability of ExBox4+ as a host, able to trap guests containing both π‐electron rich (polycyclic aromatic hydrocarbons‐PAHs) and π‐electron poor (quinoid‐ and nitro‐PAHs) moieties was investigated to shed light on the main factors that control the host–guest (HG) interaction. The nature of the HG interactions was elucidated by energy decomposition (EDA‐NOCV), noncovalent interaction (NCI), and magnetic response analyses. EDA‐NOCV reveals that dispersion contributions are the most significant to sustain the HG interaction, while electrostatic and orbital contributions are very tiny. In fact, no significant covalent character in the HG interactions was observed. The obtained results point strictly to NCIs, modulated by dispersion contributions. Regardless of whether the guests contain π‐electron‐rich or π‐electron‐poor moieties, and no significant charge‐transfer was observed. All in all, HG interactions between guests 3‐14 and host 2 are predominantly modulated by π‐π stacking.

Investigating the Solvent Effects on Binding Affinity of PAHs–ExBox4+ Complexes: An Alchemical Approach

“…Analyzing anthracene ( 2 ) and tetracene ( 5 ), from which the overlap between the rings can be well estimated by the guest rotation angle (as indicated in Figure ), in chloroform there is less overlap (and predominant electrostatic interaction), and in acetonitrile and water, the opposite is observed. This behavior is in agreement with the results cited above. This suggests that the nature of the interaction between ExBox 4+ and PAHs depends on a combination of two factors: the binding pose and the solvent polarity.…”

“…The dependence of the interaction energy composition on the binding pose was studied by Nagurniak et al in the gas phase, who performed an energy decomposition analysis EDA-NOCV (gas phase) between anthraquinone and the Ex 2 Box 4+ , an extended version of the ExBox 4+ . The results revealing that the greater the overlap of aromatic rings between host and guest, the greater the dispersive component and the smaller the electrostatic component.…”

Advances in bonding and properties of inorganic systems from relativistic calculations in Latin America

“…In addition, several host‐guest studies of lighter elements have been carried out involving the ExBox 4+ , Ex 2 Box 4+ , and CBPQT 4+ by Nagurniak and Ulloa, and the noncovalent character of hydrogen‐bond strength on triple AAA‐DDD arrays, has also been accounted for. On the other hand, Claveria‐Cádiz has proposed a series of Keggin heteropolyanions containing fifth period main group heteroatoms, [XM 12 O 40 ] n ‐ (X = Sn(IV), Sb(V) and Te(VI); M = Mo and W; n = 2,3,4), where a detailed energy decomposition analysis of the {XO 4 }‐{M 12 O 36 } interaction shows the existence of a predominant ionic character …”