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Correction: Boosted visible light photodegradation activity of boron doped rGO/g-C <sub/>3</sub> N <sub/>4</sub> nanocomposites: the role of C–O–C bonds
摘要： A series of two-component co-crystals driven by I···N interactions based on the bipyridine (BIPY) chromophore with one among three different co-former building blocks, iodopentafluorobenzene (IPFB), 1,4-diiodotetrafluorobenzene (DITFB) and 1,3,5-trifluoro-2,4,6-triiodobenzene (IFB), were prepared and analysed via infrared spectroscopy and single-crystal X-ray diffraction. By comparing the I···N distances in the co-crystal structures, we found that the higher the –F ratio in the building blocks the closer the contact of the I···N bond, enhancing the intermolecular interactions in these co-crystals as well. That is, the positive electrostatic potential on the iodine atom(s) in the co-formers was enhanced by the presence of strong electron-withdrawing groups. The distinct spectroscopic behaviours (fluorescence and Raman spectra) among the two-component BIPY co-crystal systems in response to hydrostatic pressure were also investigated. Interestingly, the fluorescence of BIPY–DITFB presented intriguing abnormal evolution from dark to bright, suggesting a new charge transfer state due to the decreased intermolecular distance and the enhanced I···N interactions. Theoretical simulations by Materials Studio also showed the shortened I···N distance and the increased angle of C–I···N, evidencing the enhanced I···N interactions. In contrast, BIPY–IFB showed only slightly enhanced fluorescence intensity at 550 nm consistent with BIPY–DITFB. Once the pressure was relieved, both the Raman and fluorescence spectra for BIPY co-crystal systems entirely self-recovered. Remarkable emission enhancement in a solid-state co-crystal has been rarely reported in previous publications and in fact, this study paves a unique way for designing and developing novel stimuli-responsive photo-functional materials.
关键词： co-crystals,piezochromic materials,halogen bond,intermolecular charge transfer,pressure-induced emission enhancement
更新于2025-11-14 15:14:40
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Enhanced Ordering and Efficient Photoalignment of Nanostructures in Block Copolymers Enabled by Halogen Bond
摘要： Fabrication and manipulation of macroscopically ordered nanostructures in polymer ?lms via supramolecular self-organization are fascinating from the viewpoints of science and technology. Here, a halogen bond (XB) was introduced into a block copolymer to facilitate its microphase separation process upon XB-driven supramolecular self-assembly. To the best of our knowledge, this is an extremely rare example to elegantly maneuver nanostructures of polymers by the emerging supramolecular interaction, XB. The nonmesogenic block copolymer composed of poly(ethylene oxide) and azopyridine-containing polymethacrylate was transformed into a supramolecular liquid-crystalline polymer through the halogen-bonded interaction between 1,2-diiodo-3,4,5,6-tetra?uorobenzene and the azopyridine group with the optimal molar ratio of 1:1. For comparison, one hydrogen-bonded liquid-crystalline polymer was also fabricated but no such ordering enhancement was acquired, indicating that both the high directionality of XB and the resulting supramolecular mesogenic ordering played key roles in the enhanced ordering of nanostructures in polymer ?lms. In addition, e?cient photoalignment and photoreorientation of nanostructures coinciding with the oriented direction of the supramolecular mesogens were also obtained by manipulating photoirradiation of linearly polarized light for the present XB-involved liquid-crystalline block copolymer, which is promising for the development of a novel generation of advanced composite liquid crystal (LC) materials.
关键词： halogen bond,supramolecular self-assembly,photoalignment,block copolymer,nanostructures
更新于2025-09-23 15:19:57
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Cocrystals with tunable luminescence colour self-assembled by a predictable method
摘要： Organic light-emitting materials play an essential role in the field of luminescent materials because they are easily prepared and they have controllable luminescent properties. Here it is shown that intermolecular interactions and luminescent properties of cocrystals can be predicted using the molecular surface electrostatic potential of selected (cid:3)-hole/(cid:2)-hole(cid:2) (cid:2) (cid:2)(cid:3) bonding donor haloperfluorobenzenes and acceptor acenaphthene (AC). Single-crystal X-ray diffraction data reveal that actual bonding patterns in five cocrystals assembled from haloperfluorobenzenes and AC are in accordance with predictable patterns of intermolecular interactions; that is (cid:3)-hole(cid:2) (cid:2) (cid:2)(cid:3) bond is the major interaction in AC–octafluoronaphthalene, AC–1,4-dibromotetrafluorobenzene and AC–1,3,5-tribromo-2,4,6-trifluorobenzene cocrystals, whereas (cid:2)-hole(cid:2) (cid:2) (cid:2)(cid:3) bond is the major interaction in AC–1,4-diiodotetrafluorobenzene and AC–1,3,5-trifluoro-2,4,6-triiodobenzene cocrystals. The luminescent properties of the cocrystals are affected by the bonding patterns between AC and haloperfluorobenzenes; the (cid:3)-hole(cid:2) (cid:2) (cid:2)(cid:3) bond leads to weak phosphorescence, whereas the (cid:2)-hole(cid:2) (cid:2) (cid:2)(cid:3) bond results in weak delayed fluorescence and relatively strong phosphorescence.
关键词： (cid:2)-hole,predictable,cocrystal,(cid:3)-hole bond,tunable luminescence colour,halogen bond
更新于2025-09-11 14:15:04