Chitosan Bio‐Based Organic–Inorganic Hybrid Aerogel Microspheres

Recently, organic–inorganic hybrid materials have attracted tremendous attention thanks to their outstanding properties, their efficiency, versatility and their promising applications in a broad range of areas at the interface of chemistry and biology. This article deals with a new family of surface‐reactive organic–inorganic hybrid materials built from chitosan microspheres. The gelation of chitosan (a renewable amino carbohydrate obtained by deacetylation of chitin) by pH inversion affords highly dispersed fibrillar networks shaped as self‐standing microspheres. Nanocasting of sol–gel processable monomeric alkoxides inside these natural hydrocolloids and their subsequent CO₂ supercritical drying provide high‐surface‐area organic–inorganic hybrid materials. Examples including chitosan–SiO₂, chitosan–TiO₂, chitosan–redox‐clusters and chitosan–clay‐aerogel microspheres are described and discussed on the basis of their textural and structural properties, thermal and chemical stability and their performance in catalysis and adsorption.     

An Organic‐Inorganic Hybrid Based on Keggin‐Type Polyoxometalate and Hypoxanthine: Synthesis,Structure, Stability,and Electrochemistry Properties

The organic‐inorganic hybrid H₅[Ag₂(hyp)₂]₂[BW₁₂O₄₀] · 9H₂O ( 1 ) (hpy = hypoxanthine), based on Keggin‐type polyoxometalate and hypoxanthine, was prepared by hydrothermal synthesis and characterized by single‐crystal and powder X‐ray diffraction, IR spectroscopy, elemental analysis, and thermogravimetry. The title compound has a two‐dimensional layer structure constructed by Keggin‐type [BW₁₂O₄₀]^5– anion, silver, and the biomolecule hyp. In addition, compound 1 exhibited excellent stability and superior activity in the electro‐catalytic oxidation of glucose.     

Hybrid Organic–Inorganic Silica Gel Carriers with Controlled Drug‐Delivery Properties

Pure and modified silica materials were synthesised by a sol–gel process and used as carrier for the controlled release of ibuprofen, selected as model drug. A one‐step synthesis was optimised for the preparation of various silica–drug composites by using tetraethoxysilane and 3‐aminopropyltriethoxysilane as precursors at different molar ratios. The presence of aminopropyl groups on the silica surface influences the drug‐delivery rate leading to a high degree the desorption process controlled.     

Organic‐Inorganic Hybrid Materials: Syntheses,X‐ray Diffraction Study,and Characterisations of Manganese,Cobalt, and Copper Complexes of Modified Bis(phosphonates)

Four new cobalt, manganese, and copper bis(phosphonates), [Co₂{Cl₂C(PO₃)₂}(H₂O)₇ · 4H₂O] ( 1 ), [Co{Cl₂C(PO₂O(C(O)C₆H₅))₂(H₂O)₅} · 2H₂O{Cl₂C(PO₂O(C(O)C₆H₅))₂}{Co(H₂O)₆}] ( 2 ), [Mn{[Cl₂C(PO₂O(C(O)C₆H₅))₂](H₂O)₃}] ( 3 ), and [Cu{(CH₂C₅H₅N)C(OH)(PO₃H)₂}₂ · 4H₂O] ( 4 ), were prepared by gel, liquid, and evaporation crystallisation methods. Compounds 1 – 4 were characterised by X‐ray single‐crystal diffraction, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. The effects of metal and various substituted groups in bis(phosphonate) ligands on the structure formation of bis(phosphonates) were studied. In the structure of 1 , the clodronic acid ligand ( L1 ) is in bischelating bonding mode, and the dinuclear units of 1 are surrounded by two‐dimensional water cluster patterns. The hydrogen bond network of compound 1 is extended to a three‐dimensional framework when the phosphonate oxygen atoms serve as hydrogen‐bond acceptors. In complex 2 , the CoO₆ octahedron shares a corner of one PCO₃ tetrahedron of the dibenzoyl derivative of clodronic acid ligand ( L2 ), and forms a two‐dimensional hydrogen bonding network, which consists of [Co(H₂O)₆}]²⁺ cations, lattice water molecules and L2 ligand molecules. Compound 3 , in turn, consists of dimeric building blocks built up of PCO₃ tetrahedra of the ligand L2 , which connect the corner‐sharing MnO₆ octahedra and form an overall 2D structure through hydrogen bonds of coordinated and crystal water molecules and phosphonate oxygen atoms. Complex 4 is among the first metal complexes of risedronic acid ( L3 ). In compound 4 , two L3 ligand molecules chelate tridentately the Cu^II atom at the center of symmetry, and the monomeric units of 4 are connected to a 3D structure through hydrogen bonding of coordinated and lattice water molecules to both protonated and deprotonated phosphonate oxygen atoms and protonated nitrogen atoms in the pyridine ring.     

Mobility Studies on Siloxane‐Based Inorganic‐Organic Hybrid Polymers by Dynamic Solid State,Suspended State,and Deuterium NMR Spectroscopy: Supported Organometallic Complexes. XXVI [1]

Organic modified siloxanes of the type RSi(OMe₂)₂(CH₂)₃C₆D₄(CH₂)₃(OMe₂)₂SiR [R = Me ( 4 ), R = OMe ( 5 )] were sol‐gel processed employing solvents of different polarity (MeOH and THF) to yield the corresponding inorganic‐organic hybrid polymers X4a — X5b with different physical properties. These polymers were investigated by multinuclear (²H, ¹³C, and ²⁹Si) solid state and ¹H suspension state NMR spectroscopy, including dynamic NMR techniques, in order to correlate the mobilities of these xerogels with physical properties, especially with the cross‐linkage.     

Organic‐inorganic Hybrid Lanthanide‐Silver Heterometallic Coordination Frameworks Constructed from Oxalate and Sulfate Anion: Syntheses,Structures, and Photoluminescent Properties

The first four examples of organic‐inorganic hybrid lanthanide‐silver heterometallic frameworks, namely, [AgLn(μ₅‐C₂O₄)(SO₄)(H₂O)₂] [Ln = Eu ( 1 ) and Sm ( 2 )] and [AgLn(μ₄‐C₂O₄)_0.5(μ₆‐C₂O₄)_0.5(SO₄)(H₂O)] [Ln = Tb ( 3 ) and Dy ( 4 )] based on oxalate and sulfate anions were synthesized by hydrothermal reactions of lanthanide oxide, silver nitrate, oxalic acid and sulfuric acid. All structures contain ladder‐like inorganic lanthanide sulfato chains, which are further connected together through silver atoms by oxalate anions with different coordination behavior (μ₅‐C₂O₄: 1 and 2 , μ₆‐C₂O₄ mixed μ₄‐C₂O₄: 3 and 4 ) to generate two types of 3D networks. The luminescent properties of these compounds were also studied.     

Organic–Inorganic Hybrid Zinc Phosphate with 28‐Ring Channels

An organic–inorganic hybrid zinc phosphate with 28‐ring channels was synthesized by use of an organic ligand instead of organic amine template under a hydro(solvo)thermal condition. This crystalline zinc phosphate contains large channels constructed from 28 zinc and phosphate tetrahedral units. The walls of the channels consist of two types of zincophosphate chains, in which the Zn atoms are coordinated by 2,4,5‐tri(4‐pyridyl)‐imidazole ligands as pendent groups. This compound exhibits yellow emission and interesting properties of removing cobalt, cadmium, and mercury cations from aqueous solution. A new two‐dimensional organic–inorganic hybrid zincophosphate was also obtained by changing the solvent mixture ratios in the synthesis.     

Highly‐Ordered Hybrid Organic‐Inorganic Isoporous Membranes from Polymer Modified Nanoparticles

Summary: Organic‐inorganic hybrid materials consisting of nanosized silica particles with surface grafted PS or PS‐b‐PMMA were synthesized using ATRP. These hybrid materials were used in the fabrication of highly‐ordered isoporous membranes. Optical characterization revealed that the membranes consisted of hexagonally ordered pores of uniform size. The combination of an open pore structure and high surface area makes isoporous membranes into materials of high interest in fields as biotechnology and photonics.

Image from optical microscope of hybrid nanoparticle membrane of SiO₂‐g‐PS with hexagonally‐ordered pores.     

Accessibility and Solid State NMR Studies on Sol‐Gel Processed Diphosphine Ligands

Novel xerogels X1 a–d were obtained by sol‐gel processing of the monomeric T‐functionalized diphosphine ligand (MeO)₃Si(CH₂)₆CH[CH₂PPh₂]₂ [1(T⁰)] with various amounts of the co‐condensing agents MeSi(OMe)₂(CH₂)₆(OMe)₂SiMe (D⁰–C₆–D⁰) and MeSi(OMe)₂(CH₂)₃(C₆H₄)(CH₂)₃(OMe)₂SiMe [Ph(1,4‐C₃D⁰)₂] . ²⁹Si CP/MAS NMR spectroscopic investigations were applied to probe the matrices and their degree of condensation. The integrity of the hydrocarbon backbone and diphosphine moiety was examined by means of solid state NMR spectroscopy (¹³C, ³¹P). To study the dynamics of the matrices and the phosphorus centers detailed measurements of relaxation time (T_1ρH) and cross polarization constants (T_SiH, T_PH) were carried out. The accessibility of the polysiloxane‐supported diphosphines was scrutinized by some typical phosphine reactions. It was found that reagents such as H₂O₂, MeI as well as bulky molecules like (NBD)Mo(CO)₄ or (COD)PdCl₂ are able to reach all phosphorus centers independent on the kind of the backbone of the matrix. SEM micrographs show the morphology of the hybrid materials and energy dispersive X‐ray spectroscopy (EDX) suggest that the distribution of the elements agree with the applied composition.     

Two Organic–Inorganic Hybrid 3D {P5W30}‐Based Heteropolyoxotungstates with Transition‐Metal/Ln–Carboxylate–Ln Connectors

Two unique organic–inorganic hybrid polyoxometalates constructed from Preyssler‐type [Na(H₂O)P₅W₃₀O₁₁₀]^14? ({P₅W₃₀}) subunits and TM/Ln–carboxylate–Ln connectors (TM=transition metal, Ln=lanthanide), KNa₇[{Sm₆Mn(μ‐H₂O)₂(OCH₂COO)₇(H₂O)₁₈}{Na(H₂O)P₅W₃₀O₁₁₀}] ? 22 H₂O ( 1 ) and K₄[{Sm₄Cu₂(gly)₂(ox)(H₂O)₂₄}{NaP₅W₃₀O₁₁₀}]Cl₂ ? 25 H₂O ( 2 ; gly=glycine, ox=oxalate) have been hydrothermally synthesized and characterized by elemental analyses, IR spectra, UV/Vis‐NIR spectra, thermogravimetric analyses, power X‐ray diffraction, and single‐crystal X‐ray diffraction. Compound 1 displays one interesting 3D framework built by three types of subunits, {P₅W₃₀}, [Sm₂Mn(μ‐H₂O)₂(OCH₂COO)₂(H₂O)₅]⁴⁺, and [Sm₄(OCH₂COO)₅ (H₂O)₁₃]²⁺, whereas 2 also manifests the other intriguing 3D architecture created by three types of subunits, {P₅W₃₀}, [SmCu(gly)(H₂O)₈]⁴⁺, and [Sm₂(ox)(H₂O)₈]⁴⁺. To our knowledge, 1 and 2 are the first 3D frameworks that contain {P₅W₃₀} units and TM/Ln–carboxylate–Ln connectors. The fluorescent properties of 1 and 2 have been investigated.     

Controllable Self‐Assembly of Organic–Inorganic Amphiphiles Containing Dawson Polyoxometalate Clusters

An organic–inorganic molecular hybrid containing the Dawson polyoxometalate, ((C₄H₉)₄N)₅H‐ [P₂V₃W₁₅O₅₉(OCH₂)₃CNHCOC₁₅H₃₁], was synthesized and its surfactant‐like amphiphilic properties, represented by the formation of bilayer vesicles, were studied in polar solvents. The vesicle size decreases with both decreasing hybrid concentration and with increasing polarity of the solvent, independently. The self‐assembly behavior of this hybrid can be controlled by introducing different counterions into the acetonitrile solutions. The addition of ZnCl₂ and NaI can cause a gradual decrease and increase of vesicular sizes, respectively. Tetraalkylammonium bromide is found to disassemble the vesicle assemblies. Moreover, the original counterions of the hybrid can be replaced with protons, resulting in pH‐dependent formation of vesicles in aqueous solutions. The hybrid surfactant can further form micro‐needle structures in aqueous solutions upon addition of Ca²⁺ ions.     

Two New Crystalline Organogermanate‐Based Inorganic‐Organic Hybrid Compounds

The bifunctional metalloligand bis(carboxyethylgermanium)sesquioxide, (HOOCCH₂CH₂Ge)₂O₃, was employed in the systematic high‐throughput (HT) investigation of the system Zn²⁺/(HOOCCH₂CH₂Ge)₂O₃/H₂O/C₄H₉OH. Two new metal‐organogermanates Zn[(OOCCH₂CH₂Ge)₂O₃] ( 1 ) and Zn₂(O₃GeCH₂CH₂COO) ( 2 ) were discovered that show two new structural motifs for this class of compounds. Whereas in compound 1 a formal intercalation in the structure of (HOOCCH₂CH₂Ge)₂O₃ is observed, 2 exhibits a new layered structure composed of CGeO₃ and ZnO₄ unit linked by μ₃‐oxygen atoms. Both connectivity modes lead to dense three‐dimensional framework structures.     

新颖有机/无机杂化配位聚合物[(DBU-H)(PbI3)]n的合成、晶体结构和量子化学研究

The coordination polymer [（DBU-H）（PbI3）]n（DBU=catena-（1,8-diazabicyclo[5,4,0]-undec-7-ene） was synthesized by self-assembly reaction of DBU and PbI2 at room temperature with pH=6.0 and structurally characterized by means of X-ray single crystal diffraction. It crystallizes in monoclinic system with space group P21/c and crystal parameters a = 1.1940（2） nm, b = 1.7409（4） nm, c = 0.81347（16） nm, β= 100.32（3）°, chemical formula C9H17N213Pb and Mr=741.15, V= 1.6635（6） nm^3, Z=4, Dc=2.959 g/cm^3, F（000）= 1304,μ（Mo Kα）= 15.687 mm^-1, the final R=0.0389 and wR=0.0635 for 2279 observed reflections with 1〉2σ（I）. Structure analysis shows that the inorganic anion chain consists of distorted PbI6 octahedra, which shares the same faces with adjacent PbI6 units to form one-dimensional infinite chains along the c-axis. Anion chains are surrounded by protonated （DBU-H）^＋ cations. Anion chains and cations are in combination with each other by static attracting forces in the crystal to form so-called organic-inorganic hybrid structure. According to the crystal structure data, quantum chemical calculation with DFT at B3LYP level was used to reveal the electronic structure of title compound.     

Biomolecule‐Doped Organic/Inorganic Hybrid Nanocomposite Film for Label‐Free Electrochemical Immunoassay of α‐1‐Fetoprotein

A new electrochemical immunosensor for the detection of α‐1‐fetoprotien (AFP) was developed based on AFP antibody (anti‐AFP)‐functionalized organic/inorganic hybrid nanocomposite membrane. To fabricate such a hybrid composite membrane, 3,4,9,10‐perylenetetracarboxylic acid‐bound thionine molecules (PTCTH) were initially doped into titania colloids (TiO₂), and then gold nanoparticles and anti‐AFP were immobilized onto the composite film in turn. Comparison with the electrode fabricated only with thionine not 3,4,9,10‐perylenetetracarboxylic acid, the immunosensor with PTCTH exhibited high sensitivity and fast electron transfer. The presence of gold nanoparticles provided a good microenvironment for the immobilization of biomolecules, enhanced the surface coverage of protein, and improved the sensitivity of the immunosensor. The modified process was characterized by scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The surface topography of the membrane was investigated by scanning electron microscopy (SEM). Under optimal conditions, the proposed immunosensor exhibited a wide linear range from 2.5 to 200.0 ng/mL towards AFP with a detection limit of 0.5 ng/mL (S/N=3). The stability, reproducibility and precision of the immunosensor were acceptable. Comparison with the conventional enzyme‐linked immunosorbent assay (ELISA), the present method did not require more labeled procedures and washing steps. Significantly, the detection methodology provides a promising approach for other proteins or biosecurities.     

An Organic–Inorganic Hybrid Cathode Based on S–Se Dynamic Covalent Bonds

A diphenyl trisulfide–selenium nanowire (DPTS‐Se) organic–inorganic hybrid cathode material is presented for rechargeable lithium batteries. During discharge, three voltage plateaus associated with three lithiation processes are observed. During recharge, the combination of the radicals formed upon delithiation leads to several new phenyl sulfoselenide compounds which are confirmed by HPLC‐QTof‐MS. The hybrid cathode exhibits superior cycling stability over pristine Se or DPTS as cathode alone. The first discharge shows a capacity of 96.5 % of the theoretical specific capacity and the cell retains 69.2 % of the initial capacity over 250 cycles. The hybrid cathode also shows a high Coulombic efficiency of over 99 % after 250 cycles. This study demonstrates that the combination of organic polysulfide and selenium can not only improve the utilization of active materials but also enhance the cycling performance.     

A Facile Preparation of Highly Thermally Stable Silver Nanoparticles Using PS‐b‐P4VP‐b‐PS Triblock Copolymer as Multidentate Ligand

Silver nanoparticles (Ag NPs) of improved thermal stability against long‐term aggregation were prepared using the polystyrene‐b‐poly(4‐vinylpyridine)‐b‐polystyrene (PS‐b‐P4VP‐b‐PS) triblock copolymer as a multidentate ligand. First, PS‐b‐P4VP‐b‐PS was synthesized by sequential reversible addition–fragmentation transfer (RAFT) polymerization of styrene and 4‐vinylpydine using a trithiocarbonate chain transfer agent (CTA). Then Ag NPs were obtained by in situ reduction of silver nitrate using PS‐b‐P4VP‐b‐PS as a multidentate ligand. The obtained Ag NPs were stable in solution for at least 24 h while being heated at 110°C. The effect of the molar ratio of N atoms of the P4VP chain segment and AgNO₃ on the stability of Ag NPs was studied, and the results suggested that Ag NPs were very stable even if the molar ratio of N atoms of the P4VP chain segment and AgNO₃ was very low. This method is promising to scale up the preparation of metal NPs with good dispersibility and thermal stability, which still remains challenging. To further improve its thermal stability, 1,4‐dibromobutane was used to chemically crosslink the P4VP chain segment in solution. However, the results proved that the crosslink method is infeasible to further improve the thermal stability of Ag NPs in this system.     

Multisite Organic–Inorganic Hybrid Catalysts for the Direct Sustainable Synthesis of GABAergic Drugs

Multisite organic–inorganic hybrid catalysts have been prepared and applied in a new general, practical, and sustainable synthetic procedure toward industrially relevant GABA derivatives. The domino sequence is composed of seven chemical transformations which are performed in two one‐pot reactions. The method produces both enantiomeric forms of the product in high enantiopurity as well as the racemate in good yields after a single column purification step. This protocol highlights major process intensification, catalyst recyclability, and low waste generation.     

有机-无机杂化材料负载的钯催化剂: 一种新型有效而可循环的无铜Sonogashira偶联反应

本文报道了有机-无机杂化材料固载的钯催化的无铜Sonogashira偶联反应。在3-[N,N-双（二苯基膦）氨基）]丙基功能化的硅胶固载的钯催化下,末端炔烃和碘代芳烃、溴代芳烃的偶联反应生成高产率相应的偶联产物。反应条件包括使用乙二醇为溶剂,三乙胺为碱。而且硅胶负载的膦钯催化剂和溶剂乙二醇经简单处理,可循环使用6次不降低活性。     

Synthesis of Pure Cementitious Phases by Sol‐Gel Process as Precursor

Calcium silicates and aluminates are the main constituents of ordinary Portland cement (OPC) and calcium aluminate cements (CAC) and therefore the pure phases are of great importance for the investigation of interactions between binder and additives or admixtures. Additionally, investigations on clinker phases doped with foreign ions enable the improvement of the performance of cements. For this purpose great amounts of pure phases are needed. These phases are hard to synthesize via a solid state reaction of solid educts. Thus there is a need for a new, more efficient route to synthesize these phases. The sol‐gel process as precursor provides an alternative to the conventional method. In this paper experimental evidence is presented for an improved synthesis of calcium silicates and aluminates via sol‐gel processes, the characterisation of these clinker phases and their hydration behaviour.