The transfer of structural mirror asymmetry from chiral molecules to the inorganic phase at solid‐liquid interfaces enabled rapid development of biomimetic chiral nanoparticles. They can be synthesized and assembled following a variety of chemical methods resulting in the broad family of chiral inorganic nanostructures (CNs). Their chemistry attracted large attention due to marked enhancement of circular dichroism and polarization rotation compared to organic molecules and particles, which opened application prospects in sensing, imaging, catalysis, nonlinear optics, electronics, and medicine. New physical, chemical and biological effects involving CNs such as giant optical activity, mechanical force‐assisted modulation of optical activity, photon‐to‐particle chirality transfer and suppression of amyloid toxicity have been observed. Marked strides toward enhancement of optical asymmetry (
Chirality is an essential geometric property unifying small molecules, biological macromolecules, inorganic nanomaterials, biological microparticles, and many other chemical structures. Numerous chirality measures have attempted to quantify this geometric property of mirror asymmetry and to correlate these measures with physical and chemical properties. However, their utility has been widely limited because these correlations have been largely notional. Furthermore, chirality measures also require prohibitively demanding computations, especially for chiral structures comprised of thousands of atoms. Acknowledging the fundamental problems with quantification of mirror asymmetry, including the ambiguity of sign‐variable pseudoscalar chirality measures, we revisit this subject because of the significance of quantifying chirality for quantitative biomimetics and describing the chirality of nanoscale materials that display chirality continuum and scale‐dependent mirror asymmetry. We apply the concept of torsion within the framework of differential geometry to the graph theoretical representation of chiral molecules and nanostructures to address some of the fundamental problems and practical limitations of other chirality measures. Chiral gold clusters and other chiral structures are used as models to elaborate a graph‐theoretical chirality (GTC) measure, demonstrating its applicability to chiral materials with different degrees of chirality at different scales. For specific cases, we show that GTC provides an adequate description of both the sign and magnitude of mirror asymmetry. The direct correlations with macroscopic properties, such as chiroptical spectra, are enhanced by using the hybrid chirality measures combining parameters from discrete mathematics and physics. Taking molecular helices as an example, we established a direct relation between GTC and optical activity, indicating that this chirality measure can be applied to chiral metamaterials and complex chiral constructs.
more » « less- PAR ID:
- 10513871
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chirality
- Volume:
- 36
- Issue:
- 6
- ISSN:
- 0899-0042
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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