This Review discusses the structure−property relationships in chiral molecules, macromolecules (polymers), and supramolecules (crystals, liquid crystals, or thin films) containing main-group elements. Chirality is a major property in our world, having a prominent influence on processes in biology, chemistry, and physics. Its impact in optics due to its interaction with electromagnetic waves gave rise to a multitude of effects, such as the Cotton effect and circularly polarized luminescence, making possible applications such as 3D displays and polarized sunglasses. Herein, a particular emphasis will be given to the influence of chirality on the conducting and optical properties of molecules or materials containing frontier heteroelements, particularly boron, silicon, phosphorus, and sulfur. These synergic materials are expected to become game-changers in the field of materials science by bringing new properties into the realm of reality, such as chirality-induced spin-selectivity, circularly polarized luminescence, and electrical magnetochiral anisotropy. This Review should be of interest for chemists and also physicists working in the fields of molecular and supramolecular chemistry, and molecular materials in the broadest sense.

A sustainable future requires highly efficient energy conversion and storage processes, where electrocatalysis plays a crucial role. The activity of an electrocatalyst is governed by the binding energy towards the reaction intermediates, while the scaling relationships prevent the improvement of a catalytic system over its volcano-plot limits. To overcome these limitations, unconventional methods that are not fully determined by the surface binding energy can be helpful. Here, we use organic chiral molecules, i.e., hetero-helicenes such as thiadiazole-[7]helicene and bis(thiadiazole)-[8]helicene, to boost the oxygen evolution reaction (OER) by up to ca. 130 % (at the potential of 1.65 V vs. RHE) at state-of-the-art 2D Ni- and NiFe-based catalysts via a spin-polarization mechanism. Our results show that chiral molecule-functionalization is able to increase the OER activity of catalysts beyond the volcano limits. A guideline for optimizing the catalytic activity via chiral molecular functionalization of hybrid 2D electrodes is given.

Crystal structures of α-humulene, a cyclic sesquiterpene, and its oxidized subproducts, were analyzed by the crystalline sponge method. Regio- and stereochemistry, including absolute configuration when a chiral oxidant was applied, and the stable conformations of all the scaffold-related compounds were successfully determined for samples on a 5-50 μg scale.

This Review discusses, along with the historical background, the principles as well as proof‐of‐concept studies of the crystalline sponge (CS) method, a new single‐crystal X‐ray diffraction (SCXRD) method for the analysis of the structures of small molecules without sample crystallization. The method uses single‐crystalline porous coordination networks (crystalline sponges) that can absorb small guest molecules within their pores. The absorbed guest molecules are ordered in the pores through molecular recognition and become observable by conventional SCXRD analysis. The complex {[(ZnI2)3(tpt)2]⋅x(solvent)}n (tpt=tris(4‐pyridyl)‐1,3,5‐triazine) was first proposed as a crystalline sponge and has been most generally used. Crystalline sponges developed later are also discussed here. The principle of the CS method can be described as “post‐crystallization” of the absorbed guest, whose ordering is templated by the pre‐latticed cavities. The method has been widely applied to synthetic chemistry as well as natural product studies, for which proof‐of‐concept examples will be shown here.

Volatile organic compounds are widely present as scents and odors in our daily lives and are readily found in a variety of natural extracts. Because these compounds are highly volatile and usually available only in minute quantities, little attention has been paid to X-ray diffraction as a technique for their structure determination. Here, we show that the structures of volatile organic compounds are easily elucidated using minute quantities of the compounds and the crystalline sponge method. The compound vapors can be directly absorbed into the sponge crystals, or alternatively, preparative gas chromatography can be used to separate the desired compound from a natural mixture.

The stereochemical outcome of the recently developed metal-free 1,2-diboration of aliphatic alkenes has, until now, only been elucidated by indirect means (e.g. derivatization). This is because classical conformational analysis of the resulting 1,2-diboranes is not viable; in the (1)H NMR spectrum the relevant (1)H resonances are broadened by (11)B, and the occurrence of the products as oily compounds precludes X-ray crystallographic analysis. Herein, the crystalline sponge method is used to display the crystal structures of the diboronic esters formed from internal E and Z olefins, evidencing the stereospecific syn addition mechanism of the reaction, which is fully consistent with the prediction from DFT calculations.

A molecular turnstile composed of a hydroquinone based rotor and a stator bearing a tridentate coordinating site can be reversibly switched between open and closed states. The locking and unlocking processes may be read optically.

Crystal structures of a-humulene,acyclic sesquiterpene,a nd its oxidized subproducts,w ere analyzed by the crystalline sponge method. Regio-and stereochemistry,including absolute configuration when achiral oxidant was applied, and the stable conformations of all the scaffold-related compounds were successfully determined for samples on a 5-50 mgscale.