A highly stable pillared and double-walled zinc(II) metal-organic framework with regular nanochannels displays single-crystal to single-crystal transformation upon desolvation and a large quantity of iodine uptake, controlled release, and electrical conductivity elevation due to synergy between the iodine guests and the host framework.

We present the syntheses, structural characterization, gas sorption, I2 uptake, and magnetic properties of a double-walled porous metal-organic framework, [Co(II)3(lac)2(pybz)2]·3DMF (1·3DMF, purple, where pybz = 4-pyridyl benzoate, lac = d- and l-lactate) and of its post-synthetic modified (PSM) congeners, [Co(II)3(lac)2(pybz)2]·xGuest (xGuest = 6MeOH, purple; 4.5EtOH, purple; 3PrOH, purple; 2C6H6, purple; 2.7I2, black), [Co(II)3(lac)2(pybz)2] (1, purple), [Co(II)3(pybz)2(lac)2(H2O)2]·7H2O (1a·7H2O, green), and [Co(III)Co(II)2(pybz)2(lac)2(H2O)2]I·2H2O·1.5DMSO (1b·I(-)·2H2O·1.5DMSO, yellow, DMSO = dimethyl sulfoxide). Crystallography shows that the framework is not altered by the replacement of DMF by different solvents or by the removal of the solvent molecules during the single-crystal to single-crystal (SC-SC) transformations, while upon exchange with H2O or partial oxidation by molecular iodine, the crystallinity is affected. 1 absorbs N2, H2, CH4, CH3OH, C2H5OH, PrOH, C6H6, and I2, but once it is in contact with H2O the absorption efficiency is drastically reduced. Upon PSM, the magnetism is transformed from a canted antiferromagnet (1·3DMF and 1·xGuest) to single-chain magnet (1), to a ferrimagnet (1a·7H2O), and to a ferromagnet (1b·I(-)·2H2O·1.5DMSO). Raman spectroscopy suggests the color change (purple to green 1a·7H2O or yellow 1b·I(-)·2H2O·1.5DMSO) is associated with a change of geometry from a strained octahedron due to the very acute chelating angle (∼60°) of the lactate of a cobalt center to a regular octahedron with a monodentate carboxylate and one H2O. The magnetic transformation is explained by the different interchain exchanges (J'), antiferromagnetic for 1·3DMF and 1·xSolvent (J' < 0), SCM for 1 (J' verge to 0), and ferromagnetic for 1a·7H2O (J' > 0), between homometal topological ferrimagnetic chains (two octahedral and one tetrahedral Co(II) ions) connected by the double walls of pybz at 13.3 Å (shortest Co···Co). For 1b·I(-)·2H2O·1.5DMSO the moment of the tetrahedral site is turned off, thus stabilizing a ferromagnetic state (J' > 0). The present stabilization of four magnetic ground states is unique in the field of metal-organic frameworks as well as the electrical conductivity of 1·2.7I2.

A covalent organic framework integrating naphthalenediimide and triphenylamine units (NT-COF) is presented. Two-dimensional porous nanosheets are packed with a high specific surface area of 1276 m g . Photo/electrochemical measurements reveal the ultrahigh efficient intramolecular charge transfer from the TPA to the NDI and the highly reversible electrochemical reaction in NT-COF. There is a synergetic effect in NT-COF between the reversible electrochemical reaction and intramolecular charge transfer with enhanced solar energy efficiency and an accelerated electrochemical reaction. This synergetic mechanism provides the key basis for direct solar-to-electrochemical energy conversion/storage. With the NT-COF as the cathode materials, a solar Li-ion battery is realized with decreased charge voltage (by 0.5 V), increased discharge voltage (by 0.5 V), and extra 38.7 % battery efficiency.

Experiments were carried out to determine the breakthrough of bacteria through a saturated aquifer sand at three flow velocities and three cell concentrations. Bacteria were either suspended in deionized water or 0.01 mol L -• NaCI solution. Bacterial transport was found to increase with flow velocity and cell concentration but was significantly retarded in the presence of 0.01 mol L -• NaC1. A mathematical model based on the advection-dispersion equation was formulated to describe bacterial transport and retention in porous media. The transport equations for bacteria were solved using the finite difference Crank-Nicolson scheme combined with Newton-Raphson iterations. The best fit of the numerical model to the experimental data was obtained using the downhill simplex optimization technique to minimize the sum of the squares of deviations between model predictions and experimental data by varying three parameters. This numerical model was found to describe the experimental data very well under all the experimental conditions tested. An alternative model (also based on the advection-dispersion equation) was tested against all the experimental data sets, but it did not represent the experimental data as well as the model proposed in this paper. face materials [e.g., Bitton et al., 1974; Wollum and Cassel, 1978; Smith et al., 1985; Parke et al., !986; Tan et al., 1991]. Many environmental factors such as ionic strength and flow velocity of the soil solution and properties of the porous materials have been identified to affect microbial transport in porous media in qualitative terms [e.g., Goldshrnid et al., 1973; Bitton et al., !974; Smith et al., !978; Wollum and Cassel, 1978; Gerba and Bitton, !984; McDowell-Boyer et al., 1986; Fontes et al., 1991; Gannon et al., 1991b; Gammack et al., 1992]. Complex mathematical models have also been developed to describe bacterial transport in porous media [e.g., Corapcioglu and Haridas, 1984, !985; Taylor and Jaffe, 1990]. Despite the experimental and modeling 1Now at Centre for Environmental Mechanics, CSIRO, Canben'a, Australia. efforts, few experimental studies have been designed to test those theoretical and conceptual approaches and to describe the aforementioned environmental factors quantitatively in relation to the microbial transport models developed. Nevertheless, it is generally accepted that bacterial transport can be described by the advection-dispersion equation with modifications to account for growth, decay, attachment, and detachment [e.g., Corapcioglu and Haridas, 1984, 1985; Taylor and Jaffe, 1990; Harvey and Garabedian, 1991; Hornberger et al., 1992; Tan et al., 1992]. Attachment refers to processes such as adsorption and straining that can cause retention of bacteria in a porous medium, and detachment refers to the subsequent dislodgment of bacteria from the surfaces. The attachment and detachment of bacteria are the most important and complex processes affecting bacterial transport and are arguably the least understood. Broadbased attempts have been made t...

Metal-organic zeolites (MOZs) are an important branch of metal-organic frameworks (MOFs) and combine the advantages of zeolites and MOFs, such as high surface area and porosity as well as the exceptional stability of zeolites, which would have a significant impact on catalysis chemistry, inorganic chemistry, coordination chemistry, materials science and other areas. In this review, we focus on the recent advances in MOZs with a brief outline of the most prominent examples. In particular, we highlight the basic principles of the design and synthesis approaches toward the construction of MOZs. Obeying the principle of charge matching, tuning tetrahedral metal centers, using enlarged tetrahedral building units as clusters, introducing functional groups into ligands, and combining traditional inorganic TO sites in MOZs enable the final materials with diverse topological structures to exhibit superior performance for various applications, such as gas sorption/separation, catalysis, enantio-selectivity, luminescence, etc.

Crystalline porous materials with diverse chemical compositions (e.g., inorganic porous materials, inorganic-organic hybrid frameworks, and covalent organic frameworks) and framework topologies have been intensively studied in the past 60 years.[1] They have wide applications in fields such as heterogeneous catalysis, gas storage, and separation.[2] Moreover, some currently emerging areas related to health, energy use, and environmental conservation and remediation are still looking for the development of new porous materials. [3][4][5] Zeolites are among the most well known porous materials because of their typical 4-connected open frameworks with TO 4 (T = Si 4+ , Al 3+ , or P 5+ etc.) building blocks and outstanding catalytic or gas separation properties. [6,7] Recently, the search for new zeolite-like structures was extended to metal-organic frameworks (MOFs), and these explorations in part produced a variety of zeolitic imidazolate frameworks (ZIFs) ). [8][9][10][11] The rich chemistry associated with the organic imidazolate building blocks in ZIFs leads to some exceptional properties, such as large surface area and high gas uptake capacities.[12] A question that emerges is: "Are there material with properties intermediate of those of zeolites and ZIFs?". It is true that there is a hybrid state that remains unknown to date.In this work, we were seeking to integrate compositional and structural features of zeolites and ZIFs by combining TO 4 tetrahedra with zinc-imidazolate units. Such a combination is trusted to bear both merits of zeolites and ZIFs, for example, possession of catalytic active TO 4 sits of zeolites and high porosity of ZIFs. Herein, we report this kind of hybrid zeolitic imidazolate framework [denoted HZIFs; general formula: M 4 (im) 6 TO 4 ] with catalytically active TO 4 (T = Mo 6+ or W 6+ ) building blocks and high thermal stability (up to 550 8C), which presents a new class of porous materials filling the gap between zeolites and ZIFs.The HZIFs reported herein are constructed from two kinds of tetrahedral building blocks and contain two kinds of connectivity, and combine structural features of both zeolites and ZIFs (Scheme 1). The TO 4 or WO 4 2À anions, and 2-methylimidazolate (2-mim) under solvothermal conditions. Both compounds were structurally characterized by single-crystal X-ray diffraction and found to be isostructural. They crystallize in the same cubic space group Im " 3 3m and have neutral three-dimensional frameworks Zn 4 (2-mim) 6 TO 4 ·x(solvent) (HZIF-1Mo: T = Mo; HZIF-1W: T = W) containing structurally disordered solvent molecules. In each structure, the tetrahedral TO 4 unit bonds to four Zn centers and the tetrahedral geometry of each Zn center is completed by three 2-mim ligands (Scheme 1 c). The whole framework topology is identified as the 4-connected net with symbol sdt, [13] which is still unknown in both zeolites and ZIFs. A prominent structural feature of this sdt-type framework is to interconnect the truncated octahedral cages of 36 ] by the inorganic Mo...

Rice (Oryza sativa L.) is a chilling-sensitive staple crop that originated in subtropical regions of Asia. Introduction of the chilling tolerance trait enables the expansion of rice cultivation to temperate regions. Here we report the cloning and characterization of HAN1, a quantitative trait locus (QTL) that confers chilling tolerance on temperate japonica rice. HAN1 encodes an oxidase that catalyzes the conversion of biologically active jasmonoyl-L-isoleucine (JA-Ile) to the inactive form 12-hydroxy-JA-Ile (12OH-JA-Ile) and fine-tunes the JA-mediated chilling response. Natural variants in HAN1 diverged between indica and japonica rice during domestication. A specific allele from temperate japonica rice, which gained a putative MYB cis-element in the promoter of HAN1 during the divergence of the two japonica ecotypes, enhances the chilling tolerance of temperate japonica rice and allows it to adapt to a temperate climate. The results of this study extend our understanding of the northward expansion of rice cultivation and provide a target gene for the improvement of chilling tolerance in rice.

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was recently identified as the causative agent for the coronavirus disease 2019 (COVID-19) outbreak that has generated a global health crisis. We use a combination of genomic analysis and sensitive profile-based sequence and structure analysis to understand the potential pathogenesis determinants of this virus. As a result, we identify several fast-evolving genomic regions that might be at the interface of virus-host interactions, corresponding to the receptor binding domain of the Spike protein, the three tandem Macro fold domains in ORF1a, and the uncharacterized protein ORF8. Further, we show that ORF8 and several other proteins from alpha- and beta-CoVs belong to novel families of immunoglobulin (Ig) proteins. Among them, ORF8 is distinguished by being rapidly evolving, possessing a unique insert, and having a hypervariable position among SARS-CoV-2 genomes in its predicted ligand-binding groove. We also uncover numerous Ig domain proteins from several unrelated metazoan viruses, which are distinct in sequence and structure but share comparable architectures to those of the CoV Ig domain proteins. Hence, we propose that SARS-CoV-2 ORF8 and other previously unidentified CoV Ig domain proteins fall under the umbrella of a widespread strategy of deployment of Ig domain proteins in animal viruses as pathogenicity factors that modulate host immunity. The rapid evolution of the ORF8 Ig domain proteins points to a potential evolutionary arms race between viruses and hosts, likely arising from immune pressure, and suggests a role in transmission between distinct host species. IMPORTANCE The ongoing COVID-19 pandemic strongly emphasizes the need for a more complete understanding of the biology and pathogenesis of its causative agent SARS-CoV-2. Despite intense scrutiny, several proteins encoded by the genomes of SARS-CoV-2 and other SARS-like coronaviruses remain enigmatic. Moreover, the high infectivity and severity of SARS-CoV-2 in certain individuals make wet-lab studies currently challenging. In this study, we used a series of computational strategies to identify several fast-evolving regions of SARS-CoV-2 proteins which are potentially under host immune pressure. Most notably, the hitherto-uncharacterized protein encoded by ORF8 is one of them. Using sensitive sequence and structural analysis methods, we show that ORF8 and several other proteins from alpha- and beta-coronavirus comprise novel families of immunoglobulin domain proteins, which might function as potential immune modulators to delay or attenuate the host immune response against the viruses.