Amorphous Thin Films of Chiral Binaphthyls for Photonic Waveguides

Abstract

The synthesis of chiral nonracemic materials and the polarization properties of chiral optical waveguides fabricated from them are presented. These materials are based on binaphthyl compounds designed to produce a glassy isotropic optically active material in a thin solid film form. Chiral-core optical waveguides may find use as novel elements in integrated optic devices for photonics applications.

EthylenedithioTetrathiafulvaleneHelicenes: Electroactive Helical Precursors with Switchable Chiroptical Properties

“…[2] Indeed, their inherent helical chirality confers to carbo-and heterohelicenes, [3] as well as to metal containing derivatives of the latter, [4] excellent chiroptical properties, such as huge optical rotations and strong circular dichroism activity, [5] making them valuable functional precursors for applications such as nonlinear optics, [6] luminescent materials, [4b,7] or, possibly, chiral wave guides. [8] Moreover, much effort is currently devoted toward the modulation of the chiroptical properties of helicenes upon irradiation or redox processes in the case where photo- [9] or electroactive [10] units are present in their structure, yet in these both reported systems the helicenic unit is not preserved in one of the commutable states. For example, in the latter, [10] a chiroptical redox switch was achieved between dihydro[5]helicenes and dicationic binaphtyl species upon reversible breaking of a C-C bond triggered by electron transfer.…”

Multifunctional and Reactive Enantiopure Organometallic Helicenes: Tuning Chiroptical Properties by Structural Variations of Mono‐ and Bis(platinahelicene)s

“…[ n ]Helicenes are composed of n ortho ‐fused aromatic rings with helical chirality and a π‐conjugated backbone, which provide them with peculiar optical and electronic properties 6. Due to this unique helical π structure, they display huge isotropic chiroptical properties (optical rotation, circular dichroism)7 that make them promising building blocks for the synthesis of functional molecular materials (for example, nonlinear optical materials,8a,b chiral wave guides,8c chiroptical switches,8d luminescent materials,8e, 9a and sensors8f). [ n ]Helicenes have also been used in organocatalysis for enantioselective transformations,10a–c as chiral derivatizing agents,10d,e and as building blocks for the design of chiral ligands for homogeneous transition‐metal catalysis 10f.…”

Forschen, publizieren, feiern

“…[ n ]Helicene derivatives are ortho ‐annulated, π‐conjugated molecules that are endowed with helical chirality 1. Enantiopure [ n ]helicenes with n≥6 can be isolated at room temperature and, owing to their unique conjugated screw‐shaped structure, they exhibit outstanding chiroptical properties, such as extremely large optical rotations;2a–c, f–h these properties make them appealing functional materials, particularly in nonlinear optics and as waveguides 2d,e. 3 One important challenge with regard to further expanding the potential of helicenes is to develop synthetic strategies that provide efficient access to a variety of helical frameworks with tunable chiroptical properties.…”