Vibrational Circular Dichroism Spectroscopy toward Intercalation Compounds of Sodium Montmorillonite: Evidences for Molecular Packing of Enantiopure Monovalent Ir(III) Complexes within Interlayer Spaces

• Published in: Applied clay science Vol. 228; p. 106621
• Main Authors: Sato, Hisako, Takimoto, Kazuyoshi, Yamagishi, Akihiko, Yoshida, Jun, Hara, Mitsuo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2022
• Subjects: Iridium complex; Montmorillonite; Vibrational circular dichroism; Montmorillonite; Iridium complex; Vibrational circular dichroism
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2022.106621

Solid state vibrational circular dichroism (SD-VCD) spectra were recorded on the intercalation compounds of sodium montmorillonite with a chiral iridium(III) complex. The complex used was Δ- (or Λ-)[Ir(bzq)2(phen)]+ (bzqH = benzo[h]quinoline; phen = 1,10-phenanthroline). The complex formed mono- or bi-molecular layers in interlayer spaces, depending on the adsorption amount to 50% or 100% cation exchange capacity (CEC), respectively. Notably, the VCD signals were sensitive enough to reveal the detailed molecular interactions in adsorption layers. Signal enhancement was achieved by the coherent delocalization of vibrational motions over tightly bound associates. Models of molecular packing were proposed with the help of theoretical simulations. Intensity of a VCD signal reflected molecular packing in the intercalation states of three-bladed propeller-type iridium(III) complexes. [Display omitted] •Mono- or bi-molecular layers were formed by enantiopure complexes at 50 or 100% CEC loading.•The packing structures of monovalent intercalated Ir(III) complexes were investigated by VCD.•VCD signals were sensitive enough to reflect intermolecular interactions.