Search

Molecular assembly is the process of organizing individual molecules into larger structures and complex systems. The self-assembly approach is predominantly utilized in creating artificial molecular assemblies, and was believed to be the primary mode of molecular assembly in living organisms as well. However, it has been shown that the assembly of many biological complexes is "catalysed" by other molecules, rather than relying solely on self-assembly. In this review, we summarize these catalysed-assembly (catassembly) phenomena in living organisms and systematically analyse their mechanisms. We then expand on these phenomena and discuss related concepts, including catalysed-disassembly and catalysed-reassembly. Catassembly proves to be an efficient and highly selective strategy for synergistically controlling and manipulating various noncovalent interactions, especially in hierarchical molecular assemblies. Overreliance on self-assembly may, to some extent, hinder the advancement of artificial molecular assembly with powerful features. Furthermore, inspired by the biological catassembly phenomena, we propose guidelines for designing artificial catassembly systems and developing characterization and theoretical methods, and review pioneering works along this new direction. Overall, this approach may broaden and deepen our understanding of molecular assembly, enabling the construction and control of intelligent assembly systems with advanced functionality. [ABSTRACT FROM AUTHOR]

High-performance NO gas sensors operating at low temperature are urgently desirable for both civilian and industrial purposes. However, it remains a great challenge to prepare tin dioxide (SnO2)-based hybrids in a simple and effective way and realize low operating temperature and high sensitivity/selectivity simultaneously. Here, we demonstrate the successful construction of a SnO2/tungsten disulfide (WS2) heterostructure using a simple hydrothermal method. By taking advantage of SnO2 nanocrystals dispersing uniformly on WS2 nanosheets and the increased oxygen vacancies as well as the existence of Sn2+, the SnO2/WS2 hybrid heterostructure shows a significant improvement in response and a much better selectivity to NO compared with the SnO2 microspheres. More importantly, the response (Rg/Ra) of the SnO2/WS2 hybrid to 5 ppm NO is 6.24 at 75 °C, which is 6.10- and 4.21-fold higher than that of the SnO2 microspheres and WS2 nanosheets, respectively. Thus, the hybrid heterostructure displays good performance with better selectivity, shorter response/recovery time and good repeatability, indicating its potential application in monitoring NO gas exhaled by humans. [ABSTRACT FROM AUTHOR]

We constructed a series of novel chiral molecular face-rotating polyhedra (FRP) from two 10,15-dihydro-5H-diindolo[3,2-a:3′,2′-c]carbazole (triazatruxene) derivatives and trans-1,2-cyclohexane diamine, and investigated how facial interactions and the positions of substituents determine the diastereoselectivity and geometry of the final assemblies. [ABSTRACT FROM AUTHOR]

Both reactive oxygen species (ROS) and mitochondria are involved in many physiological and pathological processes. Herein, we employed curved corannulene with a large dipole moment for controlled ROS production and mitochondria targeting. Corannulene was solubilized in water via complexation with gamma-cyclodextrin (1 : 2). The complex could produce type I ROS in water in a dose- and irradiation time-dependent manner. The curvature-induced dipole moment aids electron transfer and hence enables ROS generation. As a consequence of electron delocalization, which facilitates mitochondrial uptake due to the large negative membrane potential of mitochondria, mitochondrial accumulation of corannulene was demonstrated. However, this is not valid for the flat perylene control. This discovery not only presents a new tool for controlled ROS production as well as mitochondria targeting in basic biomedical research, but also opens an avenue for the potential application of curved carbon materials as therapeutic agents. [ABSTRACT FROM AUTHOR]

Li-rich manganese-based layered cathode Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 (LMNCO) nanotubes are synthesized by electrospinning and surface coated with different amounts of amorphous Al 2 O 3 . The effects of the coating content of Al 2 O 3 on the structural and electrochemical performances of LMNCO nanotubes are investigated systematically. The results show that the morphologies and structures of the samples exhibit no apparent changes after being coated with Al 2 O 3 . Electrochemical tests indicate that the Al 2 O 3 -coated LMNCO nanotubes exhibit obviously enhanced electrochemical performances. The initial coulombic efficiency of surface modified LMNCO nanotubes increased from 74.9% to 85.2%, and the modified LMNCO nanotubes have a high capacity retention of 97.6% after 90 cycles at 1C. The improved electrochemical performances of the coated samples are attributed to the protective function of the uniform Al 2 O 3 coating and the three-dimensional Li + diffusion channel in the spinel interface layer., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Narcissistic chiral self-sorting prevailed in the assembly of molecular face-rotating polyhedra from a C 3h building block 5,5,10,10,15,15-hexabutyl-truxene-2,7,12-tricarbaldehyde and racemic mixtures of 1,2-diamines. Out of 124 possible stereoisomers, a pair of racemic polyhedra dominated, wherein (1R,2R)-diamines were segregated in AAAA polyhedra and (1S,2S)-diamines in CCCC polyhedra. This chiral self-sorting process is regulated by facial non-covalent interactions in the polyhedra. In contrast, D 3h facial building blocks 1,3,5-tris-(4-formyl-phenyl)triazine and racemic mixtures of 1,2-diamines assembled into polyhedra without facial interactions, and their assembly process did not undergo apparent chiral self-sorting.