Computational Investigation of 4‑Nitrophenol Inclusion Complexes with α‑, β‑, and γ‑Cyclodextrins

TL;DR

This study uses computational methods to compare how different cyclodextrins interact with 4-nitrophenol, a contaminant, to determine which is most effective for environmental cleanup.

Contribution

The paper provides a novel computational comparison of α-, β-, and γ-cyclodextrin interactions with 4-nitrophenol using multiple theoretical methods.

Findings

α-Cyclodextrin forms the strongest and most stable complex with 4-nitrophenol.

γ-Cyclodextrin shows lower retention due to cavity–guest size mismatch.

The results support cyclodextrins as sustainable materials for environmental remediation.

Abstract

The increasing presence of emerging contaminants, such
as 4-nitrophenol
(4-NP), in aquatic environments poses environmental and public health
risks, driving interest in innovative systems capable of selectively
removing them. Despite the well-established potential of cyclodextrins
(CDs) as molecular hosts for the removal of organic micropollutants,
owing to their ability to reduce contaminant mobility and availability
while promoting capture, isolation, and preconcentration, as well
as their biodegradability and low toxicity, and increasing their chemical
versatility, a comprehensive theoretical comparison of their interactions
with 4-NP is still lacking. The present study explores the formation
and stability of inclusion complexes between 4-NP and three types
of cyclodextrins (α-CD, β-CD, and γ-CD) using a
combination of docking, molecular dynamics, and ab initio density functional theory (DFT) calculations. The results show that
α-CD exhibits the strongest and most stable interaction with
4-NP, followed by β-CD. At the same time, γ-CD exhibits
lower retention, consistent with a cavity–guest size mismatch
and structural complementarity on molecular interactions. These findings
not only provide molecular-level insights into host–guest interactions
but also reinforce the potential application of cyclodextrins as effective,
biodegradable, and reusable materials, offering theoretical support
for their use in environmental remediation strategies and their potential
for reuse, making them a sustainable and cost-effective solution.

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