The topology of polymers plays an essential role in their chemical, physical and biological properties. However, their effects on chirality-related functions remain unclear. Here, we reported the topology-controlled chirality expression in the chiral supramolecular system for the first time. Two topological supramolecular polymers, hyperbranched (HP) and linear (LP) supramolecular polymers produced by the host-guest interactions of branched and linear monomers, respectively, exhibited completely different chirality expressions despite the same molecular chirality of their monomers. Significantly, due to the branch points and strong steric hindrance existing in HP, cis-HP showed an enhanced and sign-inverted Cotton effect in the n-π* bands compared with cis-LP, as a result that the distinctive chirality induction and transfer were controlled by the topological skeletons. This topology-controlled chirality induction and transfer in the photoswitchable supramolecular polymers not only enables us to elucidate the in-depth effects of topology on the chiral expression in biopolymers but also inspires the design of chiroptical and bioinspired materials.

Chirality plays a fundamental role in the activity of biological molecules and broad classes of chemical reactions. The chemistry of life is built almost exclusively on left-handed amino acids and right-handed sugars, a phenomenon known as "homochirality of life". Furthermore, most drugs developed in the last decade are of specified chirality. Thus, fast and reliable methods that can differentiate molecules of different handedness, determine the enantiomeric excess of even molecular mixtures, and allow for an unambiguous determination of molecular handedness are of great interest, in particular with respect to complex mixtures. In this perspective article, we discuss the recent developments, with an emphasis on modern spectroscopic methods using gas-phase samples, such as photoelectron circular dichroism, Coulomb explosion imaging, and microwave three-wave mixing.

Abstract Supramolecular chirality is the major branch of supramolecular chemistry, which not only plays important roles in biological processes but also in synthetically designed aggregated systems. To understand the complex processing of biological systems, the only way is to design supramolecular chiral ensembles that mimic natural biomolecules such as Deoxyribonucleic acid (DNA), Ribonucleic acid (RNA), amino acids, etc. In addition, chiral systems and self‐assemblies as molecular motifs with breaking spatial inversion symmetry have been regarded as key substances in electronics and spintronics as well as in fundamental chemistry and physics. Here, in this review, our major concern is understanding modulation in spatial arrangements and packing modes under the impact of any external stimuli, which results in tailoring the handedness of resulted supramolecular chiral superstructures. We, in this review, highlighted the role of external stimuli such as solvent, chemical additives, photo exposure, etc. in altering the supramolecular chirality for their future utility as “active switches” in optoelectronic and spintronic devices and applications.

Chirality plays a fundamental role in chemistry, biology, and materials science, where molecular activity and performance often depend on enantiomeric purity. However, most synthetic methods produce racemic mixtures, making efficient strategies for enantioseparation and chiral amplification essential. Among the available approaches, crystallization-based methods offer scalable and mechanistically versatile routes for controlling chirality in the solid state. This review summarizes recent advances in solid-state crystallization strategies for chiral resolution, chirality generation, and enantiomeric amplification. Emphasis is placed on the structural and thermodynamic factors governing the formation of racemic compounds, conglomerates, and solid solutions, and how these phase behaviors influence separation outcomes. Key methodologies including preferential crystallization, attrition-enhanced deracemization, and multicomponent crystallization via diastereomeric salts and chiral co-crystals are discussed to illustrate how rational control of intermolecular interactions and phase equilibria enables effective enantioseparation. Emerging insights into supramolecular symmetry breaking and confinement-driven chiral amplification are also highlighted, demonstrating that solid-state processes can generate or amplify chirality even from achiral precursors. By integrating representative examples with broader conceptual analysis, this review outlines key design principles governing chiral outcomes in crystalline systems and highlights expanding applications of chiral co-crystals in pharmaceuticals and as functional materials, providing a framework for future advances in crystallization-mediated chirality control.

Chirality is a fundamental structural property of biological molecules that governs molecular recognition, enzymatic catalysis, and genetic information processing in living systems. Natural life exhibits a universal pattern of homochirality in which proteins are composed predominantly of l-amino acids, while nucleic acids contain d-sugars within their backbone structures. Advances in synthetic biology and chemical biology have stimulated growing interest in mirror biological systems that operate with inverted molecular chirality. In theory, mirror organisms would contain proteins composed of d-amino acids and nucleic acids built from l-sugars, forming a stereochemically inverted yet internally consistent biochemical framework that is largely incompatible with natural biological systems. This review examined the molecular foundations, engineering strategies, biosafety considerations, and ecological implications associated with the theoretical development of mirror bacteria. Particular emphasis is placed on the hierarchical organization of biological chirality and the stereochemical constraints that govern macromolecular folding, molecular recognition, and the processing of genetic information. Recent advances in the chemical synthesis of mirror proteins and mirror nucleic acids demonstrate that stereochemically inverted biomolecules can adopt stable structures and perform catalytic or informational functions. However, integrating these components into self replicating mirror cellular systems remains a major scientific challenge. Furthermore, the ecological interactions, evolutionary dynamics, and environmental persistence of mirror biological systems require careful biosafety evaluation and responsible governance. This review highlights key conceptual and technological challenges that must be addressed before mirror organisms can progress from theoretical constructs toward experimental feasibility.

Although chirality-mirror asymmetry-underpins biomolecular interactions, difficulties in quantifying it have long obscured insight into the precise role it plays in these interactions. Two standard chirality measures are the pseudoscalar Osipov-Pickup-Dunmur (OPD) index, which yields an asymmetry index with a sign, and the Hausdorff Chirality Measure (HCM), which yields only a magnitude. Theoretical arguments have shown that OPD is expected to have "chiral zeros," which occur when a chiral object is incorrectly assigned a chirality index value of zero. However, their existence remains theoretical and their abundance in real (bio)molecules has not been studied. We examined the differences between OPD and HCM in four different biological systems representing several different scales of chirality and found chiral zeros to be prevalent in each of these cases. Thus, we conclude that OPD is unsuitable for the quantification of chirality of complex molecular structures except in simple cases of helicoids with singular degrees of freedom for their reconfiguration. HCM also gave a weak correlation with biological properties. Altogether our findings indicate that new mathematical approaches to differentiate opposite handed chiral structures are needed especially considering the rapid prolifiration of machine learning and artificial intelligence algorithms for biochemistry and structural biology.

Although continuous symmetry theory has attracted increasing attention in modern chemistry, local symmetry remains under-investigated. As a consequence, the relationship between symmetry and chemical behavior is often obscured, limiting the practical use of fuzzy symmetry measures. Here, in this study, we introduce a novel framework for evaluating local symmetry based on electron density localization and present continuous symmetry representations for several representative molecules. Our approach not only quantitatively captures global symmetry but also reveals distinctive features of symmetry in a local chemical environment. The related concept, local chirality or chirotopicity, is also discussed. Overall, the proposed local symmetry and chirality measures provide valuable insights into molecular structure and structure–property relationships.

Chiral molecules, ubiquitous in chemistry and biology, can differentiate electrons by their spin, a phenomenon known as chirality-induced spin selectivity (CISS). Despite its robustness and technological relevance, CISS has resisted conventional explanation: Spin-orbit coupling (SOC) models cannot fully account for the observed magnitude, room-temperature persistence, or equilibrium signatures. Here, we argue that structural chirality enforces a twin-pair exchange mechanism via the indistinguishability principle, which intrinsically couples spin and spatial degrees of freedom such that wave functions cannot be factorized into spin and spatial components. We derive an effective Hamiltonian that describes both transport and equilibrium CISS phenomena and is non-Hermitian. However, the inherent pseudo-Hermiticity, with $\mathscr{PT}$ symmetry as a special case, ensures real eigenvalues and thermodynamic consistency. We demonstrate that our framework is a step toward resolving long-standing anomalies of CISS. It situates CISS alongside equilibrium symmetry-breaking phenomena such as ferromagnetism and superconductivity, with implications for spintronics, catalysis, and the origins of biological homochirality.