一种钴-取代型有机-无机杂化三维超分子多酸:合成、结构与表征

在水热条件下,成功合成了一例过渡金属钴修饰的有机-无机杂化Dawson型三维超分子多金属磷钨酸簇合物[Co(dap)_3]_2[H_2P_2W_(18)O_(62)]·11H_2O (1)(dap=1,2-丙二胺),采用X射线单晶衍射、元素分析、红外光谱及热重分析对化合物进行了结构分析和基本表征.化合物1属于正交晶系,Pnma空间群,单胞参数为a=2.688 92(7) nm,b=2.176 67(6) nm,c=1.480 93(5) nm,α=β=γ=90°.从超分子化学的角度来看,化合物1中的饱和Dawson型簇阴离子和金属-有机复合物之间通过广泛的氢键作用,进而形成有趣的4,8-连接的三维超分子网络结构.     

A new approach to predict the formation of 3D hybrid organic-inorganic perovskites

Recently, hybrid organic-inorganic perovskite (HOIPs) materials are used to enhance the power conversion efficiency of the solar cells. The tolerance factor (TF) and octahedral factor (μ) are widely used to predict the formation of three-dimensional (3D) HOIPs structures. However, in some of the cases (e.g. CH₃NH₃GeI₃ (MAGeI₃) [TF = 1.06, μ = 0.33] NH₂CHNH₂GeI₃ (FAGeI₃) [TF = 1.14, μ = 0.33] and CH₃C(NH₂)₂GeI₃ (ACGeI₃) [TF = 1.17, μ = 0.33]), these factors could not predict the formation of HOIPs structures. Thus, we have introduced a new factor based on the HOMO-LUMO energy gap of the organic cations, metal cations, anions, and volume of the organic cations. We have tested and utilized the HOMO-LUMO energy gap factor (β) on 403 ABX₃ combinations. The factor β successfully predicts and differentiate the perovskite and non-perovskite materials. Further, we also observed that for the formation of HOIPs structure, volume of the organic cation should also be in the range of 20 to 46 cm³/mol. Based on the newly reported factor, we have also designed some new organic cations which may form a 3D HOIPs structure.     

STM observations of self-assembled 1D and 2D nanoclusters of aromatic cryptand molecules deposited on highly oriented pyrolytic graphite

Aromatic cryptands can be considered as ‘pseudo fullerene molecules’, containing three separated π systems. The studied molecule [iso hexa imino cryptand (IHIC)] is made of 36 atoms of carbon, eight of nitrogen and 42 of hydrogen. Synthesis of the molecules gives a powder. Once the powder dissolved in chloroform, it is easy to deposit it on highly oriented pyrolytic graphite (HOPG) just by dipping the HOPG in the solution. After evaporation of the solvent, one-dimensional (1D) and two-dimensional (2D) structures are observed by using the scanning tunnelling microscopy technique. The 1D structures (chains) are made of nanoclusters containing typically six or sveen molecules. The distances between each molecule in a nanocluster are compared with those calculated on the basis of van der Waals' and electrostatic interactions. The theoretical approach predicts the formation of nanoclusters, in agreement with the experimental observations. Finally, the observation of an hexagonal network is compared and discussed in terms of the Moiré effect.     

Nb-Ta, Nb-Mo and Nb-V oxides prepared from hybrid organic-inorganic precursors

New hybrid organic-inorganic materials based on group 5 elements and a well-defined polymeric matrix have been prepared and used as precursors for Nb-Ta and Nb-Mo mixed oxides. In this non-conventional but easily accessible route to multimetallic oxides, a copolymer of N,N-diallyl-N-hexylamine and maleic acid was synthesised and used as matrix to stabilise inorganic species generated in solution from (NH₄)₆Mo₇O₂₄·4H₂O, NH₄VO₃, (gu)₃[Nb(O₂)₄] and (gu)₃[Ta(O₂)₄]. Solid-state studies indicate that the homogeneity of the blends can be kept up to about 0.5 mol Nb^V and Ta^V and 0.25 mol V^V per mol of repeat units of the copolymer. The calcination conditions of these homogeneous hybrid precursors were optimised to produce Nb-Mo, Nb-Ta and Nb-V oxides. While the thermal treatment of the Nb-V hybrid blends led only to a mixture of different phases, the characterisation of the final phases by X-ray diffraction (XRD) proved the formation of pure Nb₂Mo₃O₁₄ and showed that Nb-Ta oxides could be synthesised as single phases corresponding to a continuous series of solid solutions.     

Preparation and applications of hybrid organic-inorganic monoliths: a review

This review presents an overview of the properties of hybrid organic-inorganic monolithic materials and summarizes the recent developments in the preparation and applications of these hybrid monolithic materials. Hybrid monolithic materials with porosities, surface functionalities, and fast dynamic transport have developed rapidly, and have been used in a wide range of applications owing to the low cost, good stability, and excellent performance. Basically, these materials can be divided into two major types according to the chemical composition: hybrid silica-based monolith (HSM) and hybrid polymer-based monolith (HPM). Compared to the HPM, HSM monolith has been attracting most wide attentions, and it is commonly synthesized by the sol-gel process. The conventional preparation procedures of two type's hybrid organic-inorganic monoliths are addressed. Applications of hybrid organic-inorganic monoliths in optical devices, capillary microextraction (CME), capillary electrochromatography (CEC), high performance liquid chromatography (HPLC), and chiral separation are also reviewed.     

Synthesis,crystal structure,vibrational spectra,optical properties and theoretical investigation of a two-dimensional self-assembled organic-inorganic hybrid material

Organic–inorganic hybrid material of formula (C₄H₃SC₂H₄NH₃)₂[PbI₄] was synthesized and studied by X-ray diffraction, Infrared absorption, Raman scattering, UV–Visible absorption and photoluminescence measurements. The molecule crystallizes as an organic–inorganic two-dimensional (2D) structure built up from infinite PbI₆ octahedra surrounded by organic cations. Such a structure may be regarded as quantum wells system in which the inorganic layers act as semiconductor wells and the organic cations act as insulator barriers. Room temperature IR and Raman spectra were recorded in the 520–3500 and 10–3500 cm⁻¹ frequency range, respectively. Optical absorption measurements performed on thin films of (C₄H₃SC₂H₄NH₃)₂[PbI₄] revealed three distinct bands at 2.4, 2.66 and 3.25 eV. We also report DFT calculations of the electric dipole moments (μ), polarizability (α), the static first hyperpolarizability (β) and HOMO–LUMO analysis of the title compound investigated by GAUSSIAN 09 package. The calculated static first Hyperpolarizability is equal to 11.46 × 10⁻³¹ esu.     

Synthesis and characterization of luminescent organic-inorganic hybrid nanocomposite from polyhedral oligomeric silsesquioxane

<正>A novel polyhedral oligomeric silsesquioxane(POSS)-based organic-inorganic hybrid nanocomposite(EF-POSS) was prepared by Pt-catalyzed hydrosilylation reaction of octahydridosilsesquioxane(T_8H_8,POSS) with a luminescent substituted acetylene(2- ethynyl-7-(4-(4-methylstyryl)styryl)-9,9-dioctyl-9H-fluorene(EF)) in high yield.The hybrid nanocomposite was soluble in common solvents such as CH_2Cl_2,CHCl_3,THF and 1,4-dioxane.Its structure and property were characterized by FTIR, NMR,TGA,UV and PL,respectively.The results show that the hybrid nanocomposite with high thermal stability emits stable blue light as a result of photo excitation and possesses high photoluminescence quantum efficiency(φ_(FL)).     

Hybrid organic-inorganic 1D and 2D frameworks with epsilon-Keggin polyoxomolybdates as building blocks

Organic-inorganic hybrid materials based on polyoxometalate building blocks with capping La3+ ions and bidentate oxygenated ligands have been obtained by reaction at room temperature of the [epsilon-PMo12O36(OH)4[La(H2O)4]]5+ polyoxocation with glutarate (C5H6O(2)(2-)) and squarate (C4O(4)(2-)) organic ligands. [epsilon-PMo12O37(OH)3[La(H2O)4(C5H6O4)0.5]4].21 H2O (1) and [epsilon-PMo12O39(OH)[La(H2O)6]2-[La(H2O)5(C4O4)0.5]2].17 H2O (2) form unprecedented 1D chains built from alternating polyoxocations and organic ligands connected through LaO links. The structures of these materials are compared to the 2D hybrid organic-inorganic framework [NC4H12]2-[Mo22O52(OH)18[La(H2O)4]2[La(CH3CO2)2]4].8H2O (3) isolated from the hydrothermal reaction of elemental precursors (MoO(4)(2-), Mo, La3+) in acetate buffer. Compound 3 is built from previously undescribed polyoxometalate units with twenty-two MoV centers capped by six La3+ ions, four of which are bridged by acetate ligands.     

Design and characterization of 1D nanotubes and 2D periodic arrays self-assembled from DNA multi-helix bundles

Among the key goals of structural DNA nanotechnology are to build highly ordered structures self-assembled from individual DNA motifs in 1D, 2D, and finally 3D. All three of these goals have been achieved with a variety of motifs. Here, we report the design and characterization of 1D nanotubes and 2D arrays assembled from three novel DNA motifs, the 6-helix bundle (6HB), the 6-helix bundle flanked by two helices in the same plane (6HB+2), and the 6-helix bundle flanked by three helices in a trigonal arrangement (6HB+3). Long DNA nanotubes have been assembled from all three motifs. Such nanotubes are likely to have applications in structural DNA nanotechnology, so it is important to characterize their physical properties. Prominent among these are their rigidities, described by their persistence lengths, which we report here. We find large persistence lengths in all species, around 1-5 μm. The magnitudes of the persistence lengths are clearly related to the designs of the linkages between the unit motifs. Both the 6HB+2 and the 6HB+3 motifs have been successfully used to produce well-ordered 2D periodic arrays via sticky-ended cohesion.     

Photochromic hybrid organic-inorganic liquid-crystalline materials built from nonionic surfactants and polyoxometalates: elaboration and structural study

This work reports the elaboration and structural study of new hybrid organic-inorganic materials constructed via the coupling of liquid-crystalline nonionic surfactants and polyoxometalates (POMs). X-ray scattering and polarized light microscopy demonstrate that these hybrid materials, highly loaded with POMs (up to 18 wt %), are nanocomposites of liquid-crystalline lamellar structure (Lalpha), with viscoelastic properties close to those of gels. The interpretation of X-ray scattering data strongly suggests that the POMs are located close to the terminal -OH groups of the nonionic surfactants, within the aqueous sublayers. Moreover, these materials exhibit a reversible photochromism associated to the photoreduction of the polyanion. The photoinduced mixed-valence behavior has been characterized through ESR and UV-visible-near-IR spectroscopies that demonstrate the presence of W(V) metal cations and of the characteristic intervalence charge transfer band in the near-IR region, respectively. These hybrid nanocomposites exhibit optical properties that may be useful for applications involving UV-light-sensitive coatings or liquid-crystal-based photochromic switches. From a more fundamental point of view, these hybrid materials should be very helpful models for the study of both the static and dynamic properties of nano-objects confined within soft lamellar structures.     

Synthesis and study of hybrid organic-inorganic glycinium fluorozirconates

Hybrid organic-inorganic zirconium fluoride complexes, (GlyH)ZrF₅, (GlyH)ZrF₅ · 2H₂O, and (GlyH)₂ZrF₆, have been synthesized for the first time. They were studied by X-ray powder diffraction and thermal analysis, as well as IR and Raman spectroscopy. The structure of the fluorozirconates was inferred from IR and Raman spectroscopic data.     

Experimental and theoretical studies on the organic-inorganic hybrid compound: aluminum-NTCDA Co-deposited film

Electronic absorption, Fourier transform-infrared (FT-IR), and electron spin resonance spectra of aluminum-naphthalene tetracarboxylic dianhydlide (Al-NTCDA) co-deposited film have been measured at room temperature, and hybrid density functional theory (DFT) calculations have been carried out in order to elucidate the electronic states for the ground and low-lying excited states of the complexes. After the interaction of NTCDA with Al atom, the new electronic transition bands were appeared at near-IR region. The C=O stretching modes of NTCDA are red-shifted by the interaction with Al. From the DFT calculations, it was found that the electronic state of the complex at the ground state is characterized by a slight charge-transfer state expressed by (Al(4))(delta+)(NTCDA)(delta-). The binding of Al to NTCDA is strong. The C=O double-bond character of NTCDA is changed to C-O single-bond-like character by the strong interaction of Al to the C=O bond. This is the origin of the red-shift of the FT-IR spectrum. The electronic states of organic-inorganic hybrid material were discussed on the basis of theoretical results.     

s-Triazine and tri-s-triazine based organic-inorganic hybrid gels prepared from chlorosilanes by exchange reactions

Hybrid polymers [(DeltaO3)4Si3]n and [(DeltaO3)SiMe]n (where Delta = C6N7 or C3N3) have been prepared by a novel sol-gel process based on exchange reactions of MeSiCl3 or SiCl4 with C6N7(OSiMe3)3 and C3N3(OSiMe3)3.     

细胞色素c在自组装纳米膜电极上的有效固定及直接电化学

采用自组装方法将壳聚糖-纳米金(Chi-Nano Au)修饰到金(Au)电极上,并经进一步自组装细胞色素c(Cyt c),制得自组装膜电极Cyt c/Chi-Nano Au/Au.测定了自组装膜电极的循环伏安曲线(CV)及稳定性.结果表明,利用自组装膜电极Chi-Nano Au/Au可以有效地固定Cyt c,并实现直接电子转移反应.Cyt c在0.13～0.28V(vs Ag/AgCl)之间显示一对明显的可逆氧化还原峰;峰电流与扫描速度呈现良好的线性关系,线性方程为Ipc=0.063 64+0.003 51υ,线性相关系数为r=0.997 2,这表明该电极过程受吸附控制.此外,所制备的膜电极稳定性良好.     

Self-assembly of hybrid organic-inorganic polyoxovanadates: functionalised mixed-valent clusters and molecular cages

Herein we report the intra- and inter-molecular assembly of a {V(5)O(9)} subunit. This mixed-valent structural motif can be stabilised as [V(5)O(9)(L(1-3))(4)](5-/9-) (1-3) by a range of organoarsonate ligands (L(1)-L(3)) whose secondary functionalities influence its packing arrangement within the crystal structures. Variation of the reaction conditions results in the dodecanuclear cage structure [V(12)O(14)(OH)(4)(L(1))(10)](4-) (4) where two modified convex building units are linked via two dimeric {O(4)V(IV)(OH)(2)V(IV)O(4)} moieties. Bi-functional phosphonate ligands, L(4)-L(6) allow the intramolecular connectivity of the {V(5)O(9)} subunit to give hybrid capsules [V(10)O(18)(L(4-6))(4)](10-) (5-7). The dimensions of the electrophilic cavities of the capsular entities are determined by the incorporated ligand type. Mass spectrometry experiments confirm the stability of the complexes in solution. We investigate and model the temperature-dependent magnetic properties of representative complexes 1, 4, 6 and 7 and provide preliminary cell-viability studies of three different cancer cell lines with respect to Na(8)H(2)[6]·36H(2)O and Na(8)H(2)[7]·2DMF·29H(2)O.     

Layered tungsten oxide-based organic-inorganic hybrid materials: an infrared and Raman study

Tungsten oxide-organic layered hybrid materials have been studied by infrared and Raman spectroscopy and demonstrate a difference in bonding nature as the length of the interlayer organic "spacer" molecule is increased. Ethylenediamine-tungsten oxide clearly displays a lack of terminal -NH3(+) ammonium groups which appear in hybrids with longer organic molecules, thus indicating that the longer chains are bound by electrostatic interactions as well as or in place of the hydrogen bonding that must be present in the shorter chain ethylenediamine hybrids. The presence of organic molecules between the tungsten oxide layers, compared with the layered tungstic acid H2WO4, shows a decrease in the apical W=O bond strength, as might be expected from the aforementioned electrostatic interaction.