Chiral luminescent lanthanide complexes possessing strong (samarium, SmIII) circularly polarised luminescence (CPL), and their self-assembly into Langmuir-Blodgett films

Dawn E Barry; Jonathan A Kitchen; Laszlo Mercs; Robert D Peacock; Martin Albrecht; Thorfinnur Gunnlaugsson

doi:10.1039/c9dt02003a

Chiral luminescent lanthanide complexes possessing strong (samarium, Sm^III) circularly polarised luminescence (CPL), and their self-assembly into Langmuir-Blodgett films

Dalton Trans. 2019 Aug 14;48(30):11317-11325. doi: 10.1039/c9dt02003a. Epub 2019 Jul 4.

Authors

Dawn E Barry¹, Jonathan A Kitchen², Laszlo Mercs³, Robert D Peacock⁴, Martin Albrecht³, Thorfinnur Gunnlaugsson¹

Affiliations

¹ School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland. gunnlaut@tcd.ie barryd5@tcd.ie.
² Chemistry, School of Natural and Computational Sciences, Massey University, Auckland, New Zealand.
³ School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
⁴ School of Chemistry, University of Glasgow, Glasgow, G 12 8QQ, Scotland, UK.

PMID: 31271402
DOI: 10.1039/c9dt02003a

Abstract

The lanthanide directed self-assembly of chiral amphiphilic 2,6-pyridinedicarboxylic acid based ligands 1 and 2 with various Ln(CF₃SO₃)₃ (Ln = Tb^III, Sm^III, Lu^III, Dy^III) salts was studied in CH₃CN and evaluated with the expected 1 : 3 and 1 : 1 Ln : Ligand species forming in solution. Ligand chirality was retained and transferred, as depicted by circular dichroism (CD) and circularly polarised luminescence (CPL) measurements (for Tb^III and Sm^III), to the lanthanide centre upon complexation with high dissymmetry factor values for the Sm^III complexes obtained (g_lum = -0.44 and 0.29 and 0.45 and -0.23 for the ⁴G_5/2→⁶H_5/2 and the ⁴G_5/2→⁶H_7/2 transitions of Sm·1₃ and Sm·2₃, respectively). The ability of the complexes to form stable Langmuir monolayers at the air-water interface was also established while Langmuir-Blodgett films of Tb·L₃ and Sm·L₃ exhibited lanthanide luminescent emission.