3,6-Connected Metal–Organic Frameworks Based on Triscarboxylate as a 3-Connected Organic Node and a Linear Trinuclear Co₃(COO)₆ Secondary Building Unit as a 6-Connected Node

The solvothermal reactions of cobalt­(II) chloride hexahydrate and 1,3,5-benzenetribenzoic acid (H₃BTB) in anhydrous <i>N</i>,<i>N</i>′-dimethylacetamide (DMA) at two different reaction temperatures and reactant concentrations led to two 3,6-connected metal–organic frameworks (MOFs) with different net topologies based on the ligand as a <i>C</i>₃ symmetric 3-connected organic node and the linear trinuclear cobalt carboxylate cluster, Co₃(COO)₆, as a 6-connected secondary building unit (SBU). MOF [Co₃(BTB)₂(DMA)₄], <b>1</b>, with a linear trinuclear cobalt carboxylate cluster, Co₃(COO)₆, and with an inversion point symmetry with “compressed trigonal antiprismatic” 6-connectivity, is a two-dimensional (2-D) layered structure of a 3,6-connected <b>kgd</b> net topology. However, the same linear trinuclear cobalt carboxylate cluster, Co₃(COO)₆, with a 2-fold point symmetry with “compressed trigonal prismatic” 6-connectivity leads to the three-dimensional (3-D) network of <b>2</b>, with an unprecedented 3,6-connected net topology with the point symbol (4³)₂(4³·12¹²). The 2-D layered framework, <b>1</b>, shows a significant sorption hysteresis for adsorbates with relatively strong interactions with the framework, such as N₂ and CO₂

3,6-Connected Metal–Organic Frameworks Based on Triscarboxylate as a 3-Connected Organic Node and a Linear Trinuclear Co₃(COO)₆ Secondary Building Unit as a 6-Connected Node

The solvothermal reactions of cobalt­(II) chloride hexahydrate and 1,3,5-benzenetribenzoic acid (H₃BTB) in anhydrous <i>N</i>,<i>N</i>′-dimethylacetamide (DMA) at two different reaction temperatures and reactant concentrations led to two 3,6-connected metal–organic frameworks (MOFs) with different net topologies based on the ligand as a <i>C</i>₃ symmetric 3-connected organic node and the linear trinuclear cobalt carboxylate cluster, Co₃(COO)₆, as a 6-connected secondary building unit (SBU). MOF [Co₃(BTB)₂(DMA)₄], <b>1</b>, with a linear trinuclear cobalt carboxylate cluster, Co₃(COO)₆, and with an inversion point symmetry with “compressed trigonal antiprismatic” 6-connectivity, is a two-dimensional (2-D) layered structure of a 3,6-connected <b>kgd</b> net topology. However, the same linear trinuclear cobalt carboxylate cluster, Co₃(COO)₆, with a 2-fold point symmetry with “compressed trigonal prismatic” 6-connectivity leads to the three-dimensional (3-D) network of <b>2</b>, with an unprecedented 3,6-connected net topology with the point symbol (4³)₂(4³·12¹²). The 2-D layered framework, <b>1</b>, shows a significant sorption hysteresis for adsorbates with relatively strong interactions with the framework, such as N₂ and CO₂

Postsynthetic Exchanges of the Pillaring Ligand in Three-Dimensional Metal–Organic Frameworks

Metal–organic frameworks, [Ni­(HBTC)­(dabco)] (<b>2</b>) and [Ni₂(HBTC)₂(bipy)_0.6(dabco)_1.4] (<b>3</b>) (where H₃BTC is 1,3,5-benzenetricarboxylic acid, dabco is 1,4-diazabicyclo[2.2.2]­octane, and bipy is 4,4′-bipyridine), were prepared via postsynthetic ligand exchanges of [Ni­(HBTC)­(bipy)] (<b>1</b>). By controlling the concentration of dabco, we could obtain not only entropically favorable <b>2</b> with completely exchanged dabco but also enthalpically favorable <b>3</b> with selectively exchanged bipy/dabco in the alternating layers

Facile Synthesis of Ni(OH)₂/Carbon Nanofiber Composites for Improving NiZn Battery Cycling Life

Carbon nanofibers (CNFs) were successfully functionalized by the hydrothermal treatment of wet CNFs containing concentrated HNO₃. The method of synthesis was facile and eco-friendly. With the use of oxidized CNFs as substance, Ni­(OH)₂/oxidized CNFs hybrid materials were prepared by taking a two-step solution phase reaction. The XRD pattern and TEM image suggested a well crystalline Ni­(OH)₂ nanoplate with β-phase structure growth on the surface of CNFs. Electrochemistry test results displayed high specific capacitances and long cycle life of the composites. With the use of Ni­(OH)₂/CNFs as cathode and Zn foil as anode, assembled NiZn pouch cells could achieve ∼1.75 V discharge voltage plateau, with a specific capacity ranging from 184 mAh·g^–1 at a discharging current density of 5 mA·cm^–2 to 91 mAh·g^–1 at a discharging current density of 50 mA·cm^–2. Its cycle stability was up to 1200 cycles with a capacity retention of >96% at attaining an energy density of 150 Wh·kg^–1. Compared with a 6 mol·L^–1 KOH solution electrolyte battery, the sodium polyacrylate gel electrolyte battery displayed better cycle performance. The function of the gel electrolyte was discussed. The facile method could be extended to the oxidization of the other carbon materials and synthesis of the others carbon composites

Additional file 1: of Proteomic analysis of protein interactions between Eimeria maxima sporozoites and chicken jejunal epithelial cells by shotgun LC-MS/MS

Table S1. LC-MS/MS analysis of E. maxima sporozoite proteins binding to chicken jejunal epithelial cells. This file describes the details of the 204 non-redundant proteins that were identified using shotgun LC-MS/MS. (XLS 187 kb

Additional file 2: of Proteomic analysis of protein interactions between Eimeria maxima sporozoites and chicken jejunal epithelial cells by shotgun LC-MS/MS

Table S2. Eimeria maxima sporozoite soluble proteins binding to chicken jejunal epithelial cells with more than two unique peptide counts. This file describes the details of the 35 proteins binding to chicken jejunal epithelial cells that were identified with more than two unique peptide counts using shotgun LC-MS/MS. (XLS 95 kb

Enhancing Catalytic Activity and Stability of Yeast Alcohol Dehydrogenase by Encapsulation in Chitosan-Calcium Phosphate Hybrid Beads

A kind of calcium phosphate-mineralized chitosan beads (chitosan–CaP) was prepared via a one-pot method by adding droplets of Ca²⁺-containing chitosan aqueous solution into phosphate-containing sodium tripolyphosphate aqueous solution. The chitosan beads formed immediately coupled with in situ precipitation of calcium phosphate on the surface. The antiswelling properties of hybrid beads were greatly improved with the swelling degree as low as 5%. The morphology of the resultant chitosan–CaP hybrid beads was observed by scanning electron microscopy (SEM). Yeast alcohol dehydrogenase (YADH) was encapsulated in the hybrid beads with an about 40% lower enzyme leakage compared with that in the pure chitosan beads. The optimal temperature and pH value for enzymatic conversion catalyzed by YADH immobilized in the chitosan–CaP beads were 30 °C and 7.0, respectively, which were identical to those for free YADH. The immobilized YADH displayed obviously higher thermal stability, pH stability, recycling stability, and storage stability than the free YADH counterpart

Solvent-Induced Structural Dynamics in Noninterpenetrating Porous Coordination Polymeric Networks

Three novel soft porous coordination polymer (PCP) or metal–organic framework (MOF) compounds have been synthesized with a new rigid ligand <i>N</i>-(4-pyridyl)-1,4,5,8-naphathalenetetracarboxymonoimide (PNMI) by partial hydrolysis of <i>N,N′</i>-di-(4-pyridyl)-1,4,5,8-naphthalenete-tracarboxydiimide (DPNI) during solvothermal reactions with Zn­(II), Cd­(II), and Mn­(II) salts, and they are [Zn­(PNMI)]·2DMA (<b>1</b>·2DMA, <b>1a</b>), [Cd­(PNMI)]·0.5DMA·5H₂O (<b>2</b>·0.5DMA·5H₂O), and [Mn­(PNMI)]·0.75DMF (<b>3</b>·0.75DMF). The structure of <b>1</b> is based on paddle-wheel secondary building unit (SBU) with a 3,6-connected <b>rtl</b> net topology, whereas <b>2</b> and <b>3</b> are isotypical but the M­(O₂C–C)₂ fragments aggregate in one-dimension and the overall connectivity is the same <b>rtl</b> net topology. All these three MOFs have one-dimensional rhombic channels filled with guest molecules. The guest molecules in <b>1a</b> can be exchanged with EtOH in a single-crystal to single-crystal (SCSC) manner to <b>1</b>·1.25EtOH·0.375H₂O (<b>1b</b>). Further, the guest molecules in <b>1b</b> can be replaced with ethylene glycol, triethylene glycol and allyl alcohol without destroying its single crystal nature. These guest exchanges are accompanied by reduction in volume of the unit cell up to 16%, as well as the void volume up to 33.1%. Similarly, triethylene glycol (TEGly) selectively exchanges EtOH in a mixture of the above solvents, which might be the result of correct fit of the hydrogen-bonded TEGly dimer in the channel of <b>1</b>. While activated <b>1</b> and <b>3</b> exhibit no uptake of N₂ and H₂ at 1 bar and 77 K and very low uptake of CO₂ gas at 1 bar and 196 K, activated <b>2</b> shows selective CO₂ uptake, 278 cm²·g^–1, over N₂ and H₂ at 1 bar and 196 K, which corresponds to 5.87 molecules of CO₂ per formula unit of <b>2</b>

Bioinspired Approach to Multienzyme Cascade System Construction for Efficient Carbon Dioxide Reduction

An efficient multienzyme cascade system based on ultrathin, hybrid microcapsules was constructed for converting CO₂ to methanol by combining the unique functions of catechol and gelatin. Gelatin was modified with catechol groups (GelC) via well-defined EDC/NHS chemistry, thus endowed with the ability to covalently attach enzyme molecules. Next, the first enzyme (FateDH)-containing CaCO₃ templates were synthesized via coprecipitation and coated with a GelC layer. Afterward, GelC was covalently attached with the second enzyme (FaldDH) via Michael addition and Schiff base reactions. Then, GelC induced the hydrolysis and condensation of silicate, and the third enzyme (YADH) was entrapped accompanying the formation of silica particles. After removal of CaCO₃ templates, the GelCSi-based multienzyme system was obtained, in which the three enzymes were appropriately positioned in different places of the GelCSi microcapsules, and the amount of individual enzyme was regulated according to enzyme activity. The system exhibited high activity and stability for converting CO₂ into methanol. In detail, the system displayed much higher methanol yield and selectivity (71.6%, 86.7%) than that of multienzyme in free form (35.5%, 47.3%). The methanol yield remained 52.6% after nine times of recycling. This study will provide some guidance on constructing diverse scaffolds for applications in catalysis, drug and gene delivery, and biosensors

Preparation of Ultrathin, Robust Protein Microcapsules through Template-Mediated Interfacial Reaction between Amine and Catechol Groups

A novel approach to the synthesis of protein microcapsules is developed through template-mediated interfacial reaction. Protein-doped CaCO₃ templates are first synthetized via coprecipitation and then coated with a catechol-containing alginate (AlgDA) layer. Afterward, the templates are exposed to ethylenediamine tetraacetic acid disodium (EDTA) solution to dissolve CaCO₃. During CaCO₃ dissolution, the generated CO₂ gas pushes protein molecules moving to the AlgDA layer, and thereby Michael addition and Schiff base reactions proceed, forming the shell of protein microcapsules. Three kinds of proteins, namely, bovine serum albumin, catalase, and protamine sulfate, are utilized. The shell thickness of microcapsule varies from 25 to 82 nm as the doping amount of protein increased from 2 to 6 mg per 66 mg CaCO₃. The protein microcapsules have a robust but flexible shell and can be reversibly deformed upon exposure to osmotic pressure. The bioactivity of protein microcapsules is demonstrated through enzymatic catalysis experiments. The protein microcapsules remain about 80% enzymatic activity of the equivalent free protein. Hopefully, our approach could be extended to many other applications such as drug/gene delivery, tissue scaffolds, and catalysis due to the universality of Michael reaction and Schiff base reactions