Controlled Molecular Arrangement of Cinnamic Acid in Layered Double Hydroxide through pi-pi Interaction for Controlled Release

Int J Mol Sci. 2024 Apr 19;25(8):4506. doi: 10.3390/ijms25084506.

Abstract

Cinnamic acid (CA) was successfully incorporated into Zn-Al layered double hydroxide (LDH) through coprecipitation. The CA moiety was stabilized in the interlayer space through not only electrostatic interaction but also intermolecular π-π interaction. It was noteworthy that the CA arrangement was fairly independent of the charge density of LDH, showing the important role of the layer-CA and CA-CA interactions in molecular stabilization. Computer simulations using the Monte Carlo method as well as analytical approaches including infrared, UV-vis spectroscopy, and differential scanning calorimetry showed the existence of intermolecular interaction. In order to reinforce molecular stabilization, a neutral derivative of CA, cinnamaldehyde (CAD), was additionally incorporated into LDH. It was clearly shown that CAD played a role as a π-π interaction mediator to enhance the stabilization of CA. The time-dependent release of CA from LDH was first governed by the layer charge density of LDH; however, the existence of CAD provided additional stabilization to the CA arrangement to slow down the release kinetics.

Keywords: cinnamic acid; intermolecular interaction; layered double hydroxide; molecular arrangement; phenolic acid; release; π-π interaction.

MeSH terms

  • Acrolein / analogs & derivatives*
  • Acrolein / chemistry
  • Calorimetry, Differential Scanning
  • Cinnamates* / chemistry
  • Delayed-Action Preparations* / chemistry
  • Hydroxides* / chemistry
  • Kinetics
  • Monte Carlo Method

Substances

  • cinnamic acid
  • Cinnamates
  • Hydroxides
  • Delayed-Action Preparations
  • cinnamaldehyde
  • Acrolein