The use of lanthanide luminescence as a reporter in the solid state: Desymmetrization of the prochiral layers of γ-zirconium phosphate/phosphonate and circularly polarized luminescence

Abstract

Solid-state CPL measurements were performed for the first time on hybrid, laminar materials based on γ-ZrP pillared with organic diphosphonates. Ad hoc optically pure diphosphonates were synthesized and the luminescence properties of their complexation with Tb(III) were verified in solution. CD and CPL measurements showed that the bistriazolylpyridine chromophores bonded to the metal provided an effective chiral environment that produced significant signals. In the case of the γ-ZrP-derived materials, experimental evidence and simple molecular modeling hinted to the occurrence of supramolecular chirality in the particles, induced by the intrinsic dissymmetry of the organic diphosphonates or by the intercalation of chiral species such as 1-phenethylamine. Chirality at the supramolecular level was revealed in the solid state by the CPL signals measured from reporter Tb(III) ions intercalated in the hybrid matrix.

The btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] binding motif: a new versatile terdentate ligand for supramolecular and coordination chemistry

“…For instance, Brunet et al described the covalent attachment of ligands 44 and 45 to a g-zirconium phosphate surface, where they acted as sensitisers for Ln(III) emission and also circularly polarised luminescence (CPL) in the case of the chiral ligands. 94,146 In a further example, compounds 43a-b acted as agents for RAFT (reversible addition fragmentation …”

“…162 With this in mind, chiral ligands 45 were introduced covalently into the framework to combine the ability to sensitise Tb(III) emission with optical activity to produce weak CPL signals in the solid state, a seldom-measured phenomenon. 146 …”

Potential Switchable Circularly Polarized Luminescence from Chiral Cyclometalated Platinum(II) Complexes

“…The resonance light scattering (RLS) spectra were obtained by synchronously scanning the excitation and emission monochromators (namely, Δλ = 0.0 nm) of a Hitachi F-4600 fluorescence spectrophotometer in the wavelength region from 300 to 800 nm. CPL and total luminescence spectra were recorded on an instrument described previously, 17 operating in a differential photon-counting mode. The light source for excitation was a continuous wave 1000 W xenon arc lamp from a Spex Fluorolog-2 spectrofluorometer, equipped with excitation and emission monochromators with a dispersion of 4 nm/mm (SPEX, 1681B).…”

Circularly Polarized Luminescence of Silica-Grafted Europium Chiral Derivatives Prepared through a Sequential Functionalization

“…Indeed, there are only very few reports of nano-structured and organic/inorganic hybrid functional materials endowed with circularly polarized luminescence, such as CPL-active CdS quantum dots 11 or Tb complexes embedded in SiO 2 xerogel 12 or zirconium phosphate/phosphonate matrices. 13 To the best of our knowledge there is no report on CPL of materials containing Eu grafted onto an inorganic surface.…”