Acetonitrile­[2-(1-{bis­[2,4,6-tris­(trifluoro­meth­yl)phen­yl]phosphan­yloxy}-1-methyl­eth­yl)pyridine]­methyl­palladium(II) hexa­fluoridoanti­monate dichloro­methane hemisolvate

In the title compound, [Pd(CH3)(C26H14F18NOP)(C2H3N)][SbF6]·0.5CH2Cl2, the Pd2+ cation has a distorted square-planar environment, being coordinated by the acetonitrile [Pd—N = 2.078 (8) Å] and methyl [Pd—C = 2.052 (9) Å] groups and the bidentate ligand 2-(1-{bis­[2,4,6-tris­(trifluoro­meth­yl)phen­yl]phosphan­yloxy}-1-methyl­eth­yl)pyridine (L). In L, one –CF3 group is rotationally disordered between two orientations in a 1:1 ratio. The solvent mol­ecule was treated as disordered between two positions related by an inversion center with occupancies fixed at 0.5. The crystal packing exhibits weak inter­molecular C—H⋯F contacts

Acetonitrile­[2-({bis[2,4,6-tris­(trifluorido­meth­yl)phen­yl]phosphan­yloxy}meth­yl)pyridine]­meth­ylpalladium(II) hexa­fluoro­anti­monate dichloro­methane hemisolvate

In the title compound, [Pd(CH3)(C24H10F18NOP)(CH3CN)][SbF6]·0.5CH2Cl2, the PdII atom has a distorted square-planar environment being coordinated by an acetonitrile N atom [Pd—N = 2.079 (3) Å], a methyl C atom [Pd—C = 2.047 (4) Å] and the bidentate ligand 2-({[2,4,6-tris­(trifluoro­meth­yl)phen­yl]phosphan­yloxy}meth­yl)pyridine (L). In L, the short distance of 3.621 (3) Å between the centroids of pyridine and benzene rings indicates the presence of a π–π inter­action. The crystal packing exhibits weak inter­molecular C—H⋯F contacts. The solvent mol­ecule has been treated as disordered between two positions of equal occupancy related by an inversion center

1,2,3,4-Tetra­hydro­phenazine 5,10-dioxide

The complete mol­ecule of the title compound, C12H12N2O2, lies on two crystallographic symmetry elements: a twofold axis and a mirror plane. In the mol­ecular structure, the quinoxaline ring and two methyl­ene substituents lie on the mirror plane while the other two methyl­ene groups are disordered about the plane. The crystal packing is stabilized by weak inter­molecular π–π stacking inter­actions with centroid–centroid distances of 3.6803 (7) Å

Transcriptome analysis of the hepatopancreas from the Litopenaeus vannamei infected with different flagellum types of Vibrio alginolyticus strains

Vibrio alginolyticus, one of the prevalently harmful Vibrio species found in the ocean, causes significant economic damage in the shrimp farming industry. Its flagellum serves as a crucial virulence factor in the invasion of host organisms. However, the processes of bacteria flagella recognition and activation of the downstream immune system in shrimp remain unclear. To enhance comprehension of this, a ΔflhG strain was created by in-frame deletion of the flhG gene in V. alginolyticus strain HN08155. Then we utilized the transcriptome analysis to examine the different immune responses in Litopenaeus vannamei hepatopancreas after being infected with the wild type and the mutant strains. The results showed that the ΔflhG strain, unlike the wild type, lost its ability to regulate flagella numbers negatively and displayed multiple flagella. When infected with the hyperflagella-type strain, the RNA-seq revealed the upregulation of several immune-related genes in the shrimp hepatopancreas. Notably, two C-type lectins (CTLs), namely galactose-specific lectin nattectin and macrophage mannose receptor 1, and the TNF receptor-associated factor (TRAF) 6 gene were upregulated significantly. These findings suggested that C-type lectins were potentially involved in flagella recognition in shrimp and the immune system was activated through the TRAF6 pathway after flagella detection by CTLs

Inverse evolution of helicity from the molecular to the macroscopic level based on N-terminal aromatic amino acids

Precise control of the emergence of macroscopic helicity with specific handedness is promising in rationally designing chiral nanomaterials, but it is rather challenging. Herein, we present a protocol to address the transmission of helicity at a molecularly resolved level to a macroscopically resolved level, in which process supramolecular chirality undergoes an inversion. A series of N-terminal aromatic amino acids could self-assemble in water, enabling the occurrence of helicity at the molecularly resolved scale, evidenced by the single crystal structure and chiroptical responses. While it failed to transmit the helicity to the macroscopic scale for individual self-assembly, the coassembly with small organic binder through hydrogen bonding interactions allows for the emergence of helical structures at the nano/micrometer scale. Experimental and theoretical results demonstrate that the introduction of extra hydrogen bonds enables a moderate crystallinity of coassemblies with remaining one-dimensional orientation to enhance the helical growth. The transmission of helicity to higher levels by coassembly is accompanied by the helicity inversion, resulting from the exchange of hydrogen bonds. This study presents a rational protocol to precisely control the emergence of macroscopic helicity from molecularly resolved helicity with finely tailored handedness, providing a deeper understanding of the chirality origin in the assembled systems in order to facilitate the design and construction of functional chiral nanomaterials.Ministry of Education (MOE)National Research Foundation (NRF)This work is supported by the Qilu Young Scholarship Funding of Shandong University, the National Natural Science Foundation of China (21872087 and 21901145), the Natural Science Foundation of Jiangsu Province (BK20190209), and the Youth Cross-Scientific Innovation Group of Shandong University (2020QNQT003). This research is also supported by the Singapore Academic Research Fund (RT12/19) and the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03)

Chiral molecular nanosilicas

Molecular nanoparticles including polyoxometalates, proteins, fullerenes and polyhedral oligosiloxane (POSS) are nanosized objects with atomic precision, among which POSS derivatives are the smallest nanosilicas. Incorporation of molecular nanoparticles into chiral aggregates either by chiral matrices or self-assembly allows for the transfer of supramolecular chirality, yet the construction of intrinsic chirality with atomic precision in discrete molecules remains a great challenge. In this work, we present a molecular folding strategy to construct giant POSS molecules with inherent chirality. Ferrocenyl diamino acids are conjugated by two or four POSS segments. Hydrogen bonding-driven folding of diamino acid arms into parallel β-sheets facilitates the chirality transfer from amino acids to ferrocene and POSS respectively, disregarding the flexible alkyl spacers. Single crystal X-ray structures, density functional theory (DFT) calculations, circular dichroism and vibrational circular dichroism spectroscopy clearly verify the preferential formation of one enantiomer containing chiral molecular nanosilicas. The chiral orientation and chiroptical properties of POSS show pronounced dependence on the substituents of α-amino acids, affording an alternative way to control the folding behavior and POSS chirality in addition to the absolute configuration of amino acids. Through the kinetic nanoprecipitation protocol, one-dimensional aggregation enables chirality transfer from the molecular scale to the micrometer scale, self-assembling into helices in accordance with the packing propensity of POSS in a crystal phase. This work, by illustrating the construction of chiral molecular nanosilicas, paves a new way to obtain discrete chiral molecular nanoparticles for potential chiroptical applications.Published versionThis work is supported by the Qilu Young Scholarship Funding of Shandong University, the National Natural Science Foundation of China (21872087 and 21901145), the Natural Science Foundation of Jiangsu Province (BK20190209), and the Youth Cross-Scientific Innovation Group of Shandong University (2020QNQT003)

Fluorescent imprintable hydrogels via organic/inorganic supramolecular coassembly

Photoresponsive hydrogels with on/off luminescence show a promising application potential in writable information recording and display materials. However, it still remains a tremendous challenge to fabricate such hydrogels on account of the intrinsic fluorescence quenching effect and the lack of suitable responsive groups. Herein, we present fluorescent imprintable hydrogels constructed via organic/inorganic supramolecular coassembly. A photoisomeric cyanostilbene conjugated cationic surfactant exhibited an aggregation-induced emission behavior upon clay (laponite) complexation, along with excellent thixotropism brought by laponite. Macrocyclic cucurbituril[7] and β-cyclodextrin rings capable of forming host-guest complexes with the surfactant were utilized to give ternary hybrid hydrogels with luminescence and photoresponsive properties. On the account of trans-cis photoisomerization of the cyanostilbene unit, the fluorescence of the multicomponent hydrogels could undergo rapid quenching within a short irradiation period under UV light and be recovered when subjected to an annealing process. According to these properties, the imprinted fluorescent patterns using the hybrid hydrogels were erasable and rewritable. Thus, this research successfully integrates host-guest complexation and supramolecular coassembly into the fabrication of fluorescent imprintable hydrogels.Agency for Science, Technology and Research (A*STAR)National Research Foundation (NRF)This work is financially supported by the Qilu Young Scholarship Funding of Shandong University, the National Natural Science Foundation of China (21872087 and 21901145), the Natural Science Foundation of Jiangsu Province (BK20190209), and the Youth Cross-Scientific Innovation Group of Shandong University (2020QNQT003). It is also supported by the Singapore Agency for Science, Technology and Research (A*STAR) AME IRG grant (A1883c0005), and the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03). The authors acknowledge the assistance from Shandong University Structural Constituent and Physical Property Research Facilitie