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Abstract: We report a new chiral indaceno[1,2-b:5,6-b′]dithiophene bis-thiophenylpropynone (IDT-TPO) dye exhibiting very noticeable chiroptical properties in thin films. While freshly prepared samples are ECD-silent, aging triggers a giant dichroic response, with ellipticity values reaching approximately 18,000 mdeg, among the highest reported to date for thin films of chiral organic dyes as neat materials. This amplification is accompanied by an unusual flattening of the main UV-Vis absorption band, and the combination of these effects produces very large gabs values (exceeding 0.1). A thorough investigation, combining microscopy and spatially resolved chiroptical techniques with time-dependent density functional theory (TD-DFT) calculations, reveals that the intense chiroptical activity arises primarily from the consistent formation of right-handed three-dimensional (3D) helical architectures. Notably, the degree of circular polarization exhibits a non-monotonic dependence on film thickness: the maximum ECD intensity was found for a thinner film, rather than for the thickest one. This behavior is particularly promising for optoelectronic applications requiring efficient chiroptical responses in relatively thin active layers.

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Abstract: Achiral bivalent ligands capable of simultaneous occupation of both hormone binding sites of transthyretin generate a substantial and complex induced near ultraviolet circular dichroism spectrum during protein binding, revealing the dynamics of this process. Reduced temperature and pH slow the interaction and reveal two phases consistent with formation of an encounter complex and progression of the interaction through the core of the transthyretin tetramer. The x-ray structure of the protein-ligand complex confirms the endpoint of the binding trajectory and shows evidence of plasticity in the structure, with substantial disturbances of some mainchain and sidechains within and adjacent to the binding channel. This study highlights the effective complementarity of CD and x-ray investigations.

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Abstract: Microvolume UV–Vis and synchrotron radiation circular dichroism (SRCD) offer clear sustainability benefits by reducing sample and reagent consumption, yet their adoption is often limited by concerns over optical pathlength variability and low-volume dispensing inaccuracies. Here, we benchmark a μDrop™ Duo microplate workflow implemented on both a Multiskan SkyHigh spectrophotometer and the B23 HTCD/SRCD platform against conventional cuvette-based measurements, using a combination of per-well pathlength calibration, baseline subtraction, and rigorous pipetting validation. Across 32 wells, relative pathlengths showed measurable well-to-well variation, confirming that a single global correction factor is inadequate. Once corrected, microvolume spectra demonstrated quantitative agreement with cuvette references, supported by regression analysis, narrow Bland–Altman limits of agreement, and low baseline-region noise. Gravimetric evaluation of a multichannel pipette revealed substantial volume-dependent error at 20 µL, underscoring the importance of matching pipette class to microvolume operation and verifying performance under actual environmental conditions. Together, these results show that microvolume UV–Vis and SRCD workflows can achieve cuvette-level analytical reliability when appropriate calibration and QC procedures are applied. The study provides a three-tier set of best-practice recommendations—essential, recommended, and aspirational—designed to help laboratories implement greener workflows without compromising metrological integrity. This work demonstrates that sustainability and analytical performance can be mutually reinforcing when validation is embedded at each stage of microvolume analysis.

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Abstract: Chiral materials that manipulate circularly polarised light have burgeoning applications across optoelectronics, sensing and information encoding, yet the functionality of organic molecular materials is often limited by their relatively low dissymmetry factors (gabs/lum < 10−2), including towards the near infrared (λ > 700 nm). An effective strategy to amplifying gabs/lum is to optimise the chiral arrangement of chromophores, with single crystals providing intrinsic molecular ordering. Herein, we quantify the circular dichroism and circularly polarised luminescence of single crystals of a chiral L-valinol bis-perylene diimide macrocycle by Mueller–Matrix polarimetry and circularly polarised luminescence microscopy, as required for the analysis of such anisotropic materials. Through this, we see that organic crystals are valuable for understanding how supramolecular structure can be used to modify the sign, strength and energy of the chiroptical signal. Indeed, by tuning the macrocycle's π–π stacking interactions, our materials deliver strong chiroptical properties (gabs/lum > 10−2), including circularly polarised luminescence into the near infrared (λ = 780 nm).

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Abstract: Perovskite nanocrystals (PNCs) exhibiting circularly polarized luminescence (CPL) represent a promising class of materials for display and light communication technologies, owing to their emission covering the entire visible range with near-unity photoluminescence efficiency. However, these materials suffer from low selectivity in the handedness of the emitted light, with most studies focusing on green emission. We address these issues by exploiting and broadening the scope of interactions between achiral PNCs and chiral organic templates. For this purpose, we select three types of PNCs with red, green, and blue emissions and introduce them into a chiral liquid-crystalline matrix in the form of composite thin films. Electron microscopy confirmed the assembly of PNCs within nanoscale gaps formed by supramolecular, liquid crystalline structures. The obtained composites displayed a CPL dissymmetry factor glum up to ≈ 0.24. The highly dissymmetric CPL properties were found to result from an interplay between two effects: chiral assembly of PNCs within a chiral environment (intrinsic) and the selective filtering by the chiral matrix. This system enables control over the dominant factors by adjusting the CPL spectral region and type of particle assembly, providing thin film materials with highly dissymmetric and spectrally tunable CPL responses.