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Crystalline metal oxide nanosheets show exceptional catalytic performance owing to the large surface‐to‐volume ratio and quantum confinement effect. However, it is still a challenge to develop a facile and general method to synthesize metal oxide nanosheets. Herein, we report a cocrystallization induced spatial self‐confinement approach to synthesize metal oxide nanosheets. Taking the synthesis of SnO2 as an example, the solvent evaporation from KCl and SnCl2 solution induces the cocrystallization of KCl and K2SnCl6, and the obtained composite with encapsulated K2SnCl6 can be in situ converted into SnO2 nanosheets confined in KCl matrix, after water washing to remove KCl, porous SnO2 nanosheets can be obtained. Notably, a series of metal oxide nanosheets can be obtained through this general and efficient green route. In particular, porous CeO2/SnO2 nanosheets with improved surface O− species and abundant oxygen vacancies exhibit superior gas sensing performance to 3‐hydroxy‐2‐butanone. [ABSTRACT FROM AUTHOR]

Amplified spontaneous emission (ASE) is intrinsically associated with lasing applications. Inefficient photon energy transfer to ASE is a long‐standing issue for organic semiconductors that consist of multiple competing radiative decay pathways, far from being rationally regulated from the perspective of molecular arrangements. Herein, we achieve controllable molecular packing motifs by halogen‐bonded cocrystallization, leading to ten times increased radiative decay rate, four times larger ASE radiative decay selectivity and thus remarkable ASE threshold decrease from 223 to 22 μJ cm−2, albeit with a low photoluminescence quantum yield. We have made an in‐depth investigation on the relationship among molecular arrangements, vibration modes, radiative decay profiles and ASE properties. The results suggest that cocrystallization presents a powerful approach to tailor the radiative decay pathways, which is fundamentally important to the development of organic ASE and lasing materials. [ABSTRACT FROM AUTHOR]

Processes leading to enantiomerically pure compounds are of utmost importance, in particular for the pharmaceutical industry. Starting from a racemic mixture, crystallization‐induced diastereomeric transformation allows in theory for 100 % transformation of the desired enantiomer. However, this method has the inherent limiting requirement for the organic compound to form a salt. Herein, this limitation is lifted by introducing cocrystallization in the context of thermodynamic deracemization, with the process applied to a model chiral fungicide. We report a new general single thermodynamic deracemization process based on cocrystallization for the deracemization of (R,S)‐4,4‐dimethyl‐1‐(4‐fluorophenyl)‐2‐(1H‐1,2,4‐triazol‐1‐yl)pentan‐3‐one. This study demonstrates the feasibility of this novel approach and paves the way to further development of such processes. [ABSTRACT FROM AUTHOR]

Abstract: Cocrystallization involving two or more components aggregating into cocrystals allows the preparation of materials with markedly improved charge mobility. This approach however, is little explored in all‐conjugated block copolymers (BCPs). Herein, we report the first investigation into the correlation between cocrystals and charge mobility in a series of new all‐conjugated BCPs: poly(3‐butylthiophene)‐b‐poly(3‐hexylselenophene) (P3BT‐b‐P3HS) for high‐performance field‐effect transistors. These rationally synthesized rod–rod BCPs self‐assemble into cocrystals with high charge mobilities. Upon one‐step thermal annealing, their charge mobilities decrease slightly despite their increased crystallinities. After two‐step thermal annealing, P3BT‐b‐P3HS (P3BT/P3HS=2:1) and (1:1) cocrystals disappear and phase separation occurs, leading to greatly decreased charge mobilities. In contrast, P3BT‐b‐P3HS (1:2) retains its cocrystalline structure and its charge mobility. [ABSTRACT FROM AUTHOR]

Stereocomplexation is the stereoselective interaction between two opposite enantiomeric polymers through an interlocked orderly assembly. Most studies focus on the stereocomplex formation from the crystalline opposite enantiomers having the identical structure; nevertheless, rare examples were reported regarding the crystalline stereocomplexes from enantiomeric polymers having different chemical structures. Herein we show a strategy for polymer orderly assembly through the formation of crystalline hetero-stereocomplexed polymeric materials by the cocrystallization of amorphous isotactic polycarbonates with different chemical structures and opposite configurations. The behaviors in the crystalline state are significantly different from that of the component enantiomeric polymers or their homo-stereocomplexes. This study is expected to open up a new way to prepare various semicrystalline materials having a wide variety of physical properties and degradability. [ABSTRACT FROM AUTHOR]

The article discusses the synthesis of two isostructural explosive cocrystals that have different thermodynamic stabilities. Each cocrystal contained diacetone diperoxide (DADP) and paired with either 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) or 1,3,5-tribromo-2,4,6-trinitrobenzene (TBTNB). It was found that the DADP/TBNTB cocrystal was unstable. The authors conclude that the DADP/TBTNB cocrystal is formed only by means of kinetic growth methods.