Computational investigation of dimethoate and β-cyclodextrin inclusion complex: molecular structures, intermolecular interactions, and electronic analysis

Abstract

The proposed study concerns the inclusion complexation of dimethoate (DMT) in the β-cyclodextrin (β-CD) molecule cage using a 1:1 stoichiometry. The interactions between DMT and -CD were evaluated using PM7 and DFT in water and gas with base 6-31G(d,p); using the CAMB3LYP functional.All approaches agree with the optimal 3D structure, which includes full DMT inclusion in the CD cavity. Complexation, LUMO, and HOMO energies were computed. The natural bond orbital (NBO) and UV-visible calculations were determined and discussed. Additionally, the non-covalent intermolecular interactions between dimethoate and β-cyclodextrin are investigated through: reduced density gradient (RDG), non-covalent interaction (NCI) and independent gradient model (IGM) that the main forces stabilizing the examined inclusion complex are H-bond and Van Der Waals interactions. Furthermore, the energy decomposition analysis (EDA) emphasizes the importance of the H-bond as attractive interactions.

Unveiling the synergy: a combined experimental and theoretical study of β-cyclodextrin with melatonin

“…Many computational standalone works provide results on the HOMO–LUMO orbitals and how they are modified by the complexation phenomenon, the binding energies of the host–guest system and structural information such as the hydrogen bonds distribution either of the CD alone or of the inclusion complex. 48–53 DFT calculations were also performed on systems involving other CDs, in particular, α- and γ-CDs with their suitable guest partners, 54–58 according to the size of the drug and the hole of the CD. Another strategy to further optimize the complexation/release mechanism of these systems is also to model various derivatized types of CDs, 59–61 by substituting –OH moieties with –OR chains.…”

Exploration of the Conformational Scenario for α-, β-, and γ-Cyclodextrins in Dry and Wet Conditions, from Monomers to Crystal Structures: A Quantum-Mechanical Study

“…In recent years, CDs have received much attention from the scientific community in a wider variety of applicative fields: in cosmetics [9][10][11] and in the food industry for odor and taste control [12][13][14][15][16]; in the environmental sector for heavy metal and pollutant removal [17][18][19][20][21][22]; and in the chemical/pharmaceutical sector as Drug Delivery Systems (DDS), i.e., high-performance carrier materials to deliver an established amount of drug to the targeted site within a specific period of time [6,[23][24][25][26][27][28]. In the last decade, many computational works have been conducted aiming at an atomistic interpretation of the inclusion and release processes for several different guest molecules [29][30][31][32][33][34][35][36], such as amino acids [37][38][39], vitamins [40], unsaturated acids [41], and antioxidants molecules [42]. The broad applicability of the CD molecule is due to its very versatile properties: it can form 1:1, 2:1, and 2:2 type complexes (even if other ratios are also possible [43]), adapting itself to the size and properties of the guest molecule, by either complexing the guest dimers of small molecules or forming host dimers with large guest molecules [44].…”