Two-Photon Circularly Polarized Luminescence of Chiral Eu Complexes

Abstract

We report the synthesis of chiral lanthanide complexes with extended π conjugation for efficient circularly polarized luminescence (CPL) via two-photon excitation (2PE). The pyridine bis-oxazoline (PyBox) core provides the chiral Ln 3+ environment, while the extension of the conjugated backbone through the pyridine 4-position with a phenylacetylene unit increases the twophoton absorption cross section. This work presents an important step toward the development of chiral systems displaying enhanced nonlinear optical properties, with potential applications in imaging and sensing, as well as in photodynamic therapy due to the selective excitation of molecules within a specific focal volume.

General Strategy to Prepare Nondoped Circularly Polarized Luminescent Liquid Crystal Materials with Tunable Performance

“…One of the most common methods to obtain CPL materials is to covalently link luminescent and chiral components through chemical synthesis. A series of CPL materials were obtained using this method, including metal complexes, , organic small molecules, − π-conjugated polymers, − and so forth. In addition, CPL materials can also be obtained by introducing chiral dopants or chiral environment into achiral luminescent materials through physical doping method. − Regardless of the method used to prepare CPL materials, the chiral arrangement of chromophores is the key to achieving CPL.…”

Towards opto-structural parameters to enhance the circularly polarized luminescence brightness of EuIII β-diketone complexes with chiral auxiliary ligands

“…12 Yet, the lack of compounds matching such features as well as the absence of guidelines to optimize their properties still limit practical applications, especially for chiral lanthanide (Ln III ) complexes, which have excelled to improve the luminescence dissymmetry factor. 12–15 Therefore, optimizing the structural and electronic features of Ln III complexes presenting CPL has become a subject of great scientific importance within the luminescence field since they can be employed in novel exciting applications that can help to fill the gap between basic synthetic chemistry and practical applications in this field.…”

Novel nonlinear chiroptical scattering effects

“…[10,11,12] They tend to be quite intricate, and they can engage both electric and magnetic resonances in materials, which leads to further enhancing light-matter interactions. [13,14] quantum dots, [22] plasmonic nano-rotamers, [23] rare-earth complexes, [24,25] gold nanoplates, [26] plasmonic helicoids, [27] chiral alloyed nanorods, [28] chiral gold nanorods, [29] coated chiral nanorods, [30] aromatic oligoamide foldamers, [31] chiral crystals, [32] as well as variety of shadow grown nanostructures, [33,34] etc. Applications of such scattering effects include displays, [35] and nanorobotics, [36] among others.…”