Probing the adsorption configuration of methanol at a charged air/aqueous interface using nonlinear spectroscopy.

Investigating the effects of electrolyte ions on the adsorption configuration of methanol at a charged interface is important for studying the interface structure of electrolyte solutions and the oxidation mechanism of methanol in fuel cells. This study uses sum frequency generation (SFG) and heterodyne-detected second harmonic generation (HD-SHG) to investigate the adsorption configuration of methanol at the air/aqueous interface of 0.1 M NaClO solution, 0.

Direct observation of long-range chirality transfer in a self-assembled supramolecular monolayer at interface in situ.

Due to the interest in the origin of life and the need to synthesize new functional materials, the study of the origin of chirality has been given significant attention. The mechanism of chirality transfer at molecular and supramolecular levels remains underexplored. Herein, we study the mechanism of chirality transfer of N, N'-bis (octadecyl)---(anthracene-9-carboxamide)-glutamic diamide (--GAn) supramolecular chiral self-assembled at the air/water interface by chiral sum-frequency generation vibrational spectroscopy (chiral SFG) and molecular dynamics (MD) simulations.

In situ nonlinear optical spectroscopic study of the structural chirality in DPPC Langmuir monolayers at the air/water interface.

We conduct a molecular study on the structural chirality in Langmuir monolayers composed of dipalmitoylphosphatidylcholine (DPPC) using in situ nonlinear optical spectroscopies, including second harmonic generation (SHG) and sum frequency generation (SFG). Chiral SHG response is observed from L-DPPC monolayers at moderate surface pressures and almost vanishes at a high surface pressure. SFG spectra of L-DPPC monolayers show chiral features that can be assigned to the terminal CH groups and the CH groups attached to the chiral center atom.

Guanosine Assembly Enabled Gold Nanorods with Dual Thermo- and Photoswitchable Plasmonic Chiroptical Activity.

Noble metal nanostructures with plasmonic circular dichroism (PCD) have attracted interest, and a modulation of PCD is of great importance for their potential applications. Herein, we propose a supramolecular strategy for achieving dual thermal and photoswitchable PCD. When guanosine (G), deoxyguanosine (dG), and boric acid modified achiral gold nanorods (GNRs) were coassembled into a hydrogel, hybrid nanofibers with PCD were produced.

Hierarchically Chiral Lattice Self-Assembly Induced Circularly Polarized Luminescence.

Biomaterials in nature often exhibit hierarchical chiral structures with an intriguing mechanism involving hierarchical chirality transfer from molecular to supramolecular and the nano- or microscale level. To mimic the cross-level chirality transfer, we present here one kind of host-guest complex system built of β-cyclodextrin (β-CD), sodium dodecyl sulfate (SDS), and fluorescent dyes, which show multilevel chirality, including molecular chirality of β-CD, induced supramolecular chirality of β-CD/SDS host-guest complexes, a chiral lattice self-assembled nanosheet, mesoscopic chirality of an assembled helical tube, induced chirality of a dye-doped chiral tube. The hierarchical chirality involved a chiral lattice self-assembly process, which can be identified by small-angle X-ray scattering, optical studies, circular dichroism, and circularly polarized luminescence spectral measurements.

Amplifying Dissymmetry Factor of Upconverted Circularly Polarized Luminescence through Chirality-Induced Spin Polarization in the Photon Upconversion Process.

A general phenomenon about upconverted circularly polarized luminescence (UC-CPL) based on triplet-triplet annihilation (TTA) was realized in an ambient environment by coupling three kinds of chiral acceptors with corresponding achiral sensitizers. All of the dissymmetry factors of UC-CPL exhibited significant amplification compared with the prompt CPL of the used chiral acceptors. Chirality-induced spin polarization during the TTA-UC process was in charge of the amplified dissymmetry factor of UC-CPL.

Two-Photon Absorption-Based Upconverted Circularly Polarized Luminescence Generated in Chiral Perovskite Nanocrystals.

Upconverted circularly polarized luminescence (UCPL) processes have attracted great interest, because the chiroptical properties could be expressed in different photophysical processes. In this Letter, the first example of two-photon absorption-based upconverted circularly polarized luminescence (TP-UCPL) is demonstrated. The chiral α-octylamine-modified cesium lead bromides perovskite nanocrystals exhibited TP-UCPL with a two-photon absorption cross section at 800 nm (σ) up to 3.

(R)-Binaphthyl derivatives as chiral dopants: substituent position controlled circularly polarized luminescence in liquid crystals.

A series of nonbridged axially chiral binaphthyl derivatives were synthesized and used as chiral dopants for chiral nematic liquid crystals (N*-LCs). It was found that binaphthyl derivatives substituted at 3,3' positions or 2,2' positions of binaphthyl rings could induce N*-LCs to show opposite circularly polarized luminescence (CPL) signals, despite having the same configuration. Additionally, a CPL switch could be constructed in these N*-LCs regulated by the applied electric field.