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Three MoO3-1,10-phenanthroline intercalation compounds were synthesized at room temperature, by suspending α-MoO3 in a water–ethanol solution of 1,10-phenanthroline. The obtained hybrid matrices were characterized by elemental analysis, infrared spectroscopy, thermogravimetry, X-ray diffractometry and scanning electron microscopy. Based on X-ray diffraction data, can be verified that ate two possible orientations of 1,10-phenanthroline into MoO3 interlayer space: an orientation to allow the interaction of the nitrogen atoms with the acidic Lewis sites on the oxide surface (d=1.10 nm), and another orientation to allow the interaction of the π electrons with such sites (d=0.76 nm). The SEM micrographs show that as the 1,10-phenanthroline total amount is increased, there is a progressive exfoliation of the oxide grains, resulting in the total disruption of the initial platy morphology. [Copyright &y& Elsevier]

A series of woven fabric laminar composite plates and narrow strips were fabricated from a variety of pitch-based pristine and bromine intercalated graphite fibers in an attempt to determine the influence of the weave on the electrical and thermal conduction. It was found generally that these materials can be treated as if they are homogeneous plates. The rule of mixtures describes the resistivity of the composite fairly well if it is realized that only the component of the fibers normal to the equipotential surface will conduct current. When the composite is narrow with respect to the fiber weave, however, there is a marked angular dependence of the resistance which was well modeled by assuming that the current follows only along the fibers (and not across them in a transverse direction), and that the contact resistance among the fibers in the composite is negligible. The thermal conductivity of composites made from less conductive fibers more closely followed the rule of mixtures than that of the high conductivity fibers, though this is thought to be an artifact of the measurement technique. Electrical and thermal anisotropy could be induced in a particular region of the structure by weaving together high and low conductivity fibers in different directions, though this must be done throughout all of the layers of the structure as interlaminar conduction precludes having only the top layer carry the anisotropy. The anisotropy in the thermal conductivity is considerably less than either that predicted by the rule of mixtures or the electrical resistivity. [Copyright &y& Elsevier]

Aluminium chloride intercalation in graphite was studied by anodic oxidation of compacted graphite (rod) and graphite powder electrodes in sodium chloroaluminate melt saturated with sodium chloride at 175 °C. The studies carried out by employing both galvanostatic and cyclic voltammetric techniques had shown that the intercalation reactions take place only beyond the chlorine evolution potential of +2.2 V vs. Al on both the electrodes. The extent of intercalation reaction was directly related to the anodic potential and probably to the amount of chlorine available on the graphite anodes. In the case of graphite powder electrode, a distinctly different redox process was observed at sub-chlorine evolution potentials and this was attributed to the adsorption of chlorine on its high surface area. This finding contradicts a report in the literature that the intercalation reactions occur at potentials below chlorine evolution in the chloroaluminate melt. [Copyright &y& Elsevier]

Graphite intercalation compound (GIC), CuCl2–FeCl3–H2SO4, is prepared first time by hydrothermal synthesis. This novel synthetic approach could lead to the preparation of other GICs. The effects of major synthetic conditions on the hydrothermal intercalation reaction are studied. Structural models for this newly synthesized material are also discussed based on the results of X-ray diffraction and XPS analysis of freshly cleaved thin crystal. [Copyright &y& Elsevier]

Both covalent (obtained by direct fluorination at high temperature) and semi-ionic carbon fluorides (synthesized at room temperature) were reduced in order to obtain disordered carbons containing very small content of fluorine and different physical properties according to the reduction treatment (chemical, thermal or electrochemical). After a physical characterization (X-ray diffraction, electron spin resonance and FT-IR spectroscopies), the electrochemical behaviours of the pristine carbon fluorides and of the treated samples were investigated during the insertion of lithium using liquid carbonate-based electrolytes (LiClO4–EC/PC, 50:50%, v/v). Both galvanostatic and voltammetric modes were performed and revealed that the voltage profiles and the capacities differed according to the starting material and the reduction treatment. Semi-ionic carbon fluoride treated in F2 atmosphere for 2 h at 150 °C and then chemically reduced in KOH exhibits high reversible capacities (the reversible capacity is 530 mAh g−1 in the second cycle); in this case, the voltage profiles show a large flat portion at potentials lower than 0.3 V which is attributed to the insertion/deinsertion of lithium ions between the small graphene sheets and/or the absorption of pseudo metallic lithium into the microporosity of the sample. Nevertheless, a part of the lithium ions are removed at potentials higher than 0.5 V versus Li+/Li limiting the useful capacity. [Copyright &y& Elsevier]

The effect of the anion charge on the structure of [LiAl2(OH)6]nX (X = Cl-, Br-, I-, SO42-, C6H8O42-) intercalation compounds and the water effect on the structure of [LiAl2(OH)6]Cl·nH2O have been studied using 1H, 7Li, and 27Al NMR. A change in the charge on the anion leads to significant changes in the asymmetry parameter for the lithium and aluminum nuclei with relatively small changes in the quadrupolar coupling constant and the broadening factor. The structure of the intermediate [LiAl2(OH)6]Cl·0.5H2O hydrate can be represented as a derivative of the structure of the anhydrous [LiAl2(OH)6]Cl intercalate with a slightly increased layer thickness and a minor orthorhombic distortion of the hexagonal cell; the water molecules partially fill the interlayer voids and participate in the diffusion process. Further hydration of the intercalate (x ≥ 1) leads to a minor (0.2Å) increase in the layer thickness and is accompanied by disordering of chloride ions and water molecules in the interlayer space. [ABSTRACT FROM AUTHOR]

Numerous channel- or tunnel-structured compounds are interesting materials in which lithium intercalation occurs primarily without destruction of the host lattice assuming a complete charge transfer. In many cases, the rigid-band model (RBM) is a useful first approximation for describing the changes in electronic properties of the host material with intercalation. The applicability of the rigid-band model is taken as a test for the properties most desirable in a good intercalation material. This review paper presents experimental results, namely optical and electrical measurements, obtained on various intercalation materials such as dichalcogenides, trichalcogenides and oxides to probe the validity of the RBM. The impact of the lithium intercalation is discussed for various structural forms, from well-crystallised to amorphous compounds. We observed, nevertheless, that the rigid-band model is not applicable to all of the layered intercalation materials. This needs yet to be more extensively documented for their promising application as insertion electrode in rechargeable lithium batteries. Compounds such as TiS2, TaS2, MoS2, NiPS3, MoO3, V2O5, V6O13, LiCoO2, LiNiO2, LiMn2O4 and LiNiVO4 are tested in this work. Some guidelines are established for improving the performances of these materials in their most eminent applications. [Copyright &y& Elsevier]

Flexible graphite is an effective heating element. It provides temperatures up to 980 °C (though burn-off occurs in air at 980 °C), response half-time down to 4 s, and heat output at 60 s up to 5600 J. The electrical energy for heating by 1 °C is 1–2 J in the initial portion of rapid temperature rise. The temperature and heat output increase with decreasing thickness and with increasing power. [Copyright &y& Elsevier]

The synthesis of new intercalation compounds obtained introducing the organic radical 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl-3-oxide (NITpBAH) in layered inorganic hosts via topotactic anion exchange reactions or exchange of anionic ligands is presented. Three different inorganic hosts were employed, two LDH-phases (Mg&z.sbnd;Al&z.sbnd;CO3 and Zn&z.sbnd;Al&z.sbnd;Cl) and the butanoxy derivative of λ-zirconium phosphates. In all cases the intercalation procedure was successfully accomplished. The percentage of exchanged anions obtained was 27, 45, 40% for Mg&z.sbnd;Al&z.sbnd;LDH, Zn&z.sbnd;Al&z.sbnd;LDH and λ-ZrPO4[O(CH2)3CH3]DMSO, respectively. The magnetic properties of the intercalated compounds were measured with a SQUID magnetometer and compared to those of a polycrystalline powder of the pure radical. The intercalation process does not change the nature of magnetic intermolecular interactions which remain antiferromagnetic but reduces their magnitude. [Copyright &y& Elsevier]

The electrochemical features of the sol–gel birnessite MnO1.84·0.6H2O are reported here in terms of OCV data, cycling behavior kinetics of Li transport in the oxide.We have confirmed that the sol–gel birnessite remains one of the best manganese oxides as rechargeable cathodic materials with an initial specific capacity of 270 mAh g−1 due to the high amount of Mn(IV). However, from a practical viewpoint, this hydrated compound has been proved to exhibit an important and constant capacity fading in the potential window 4.2–2 V associated with a strong disordering process. The ac impedance measurements have proved this behavior was mainly due to an increase of the cathode impedance and a strong decrease in kinetics of Li transport in the oxide.Such a phenomenon can be overcome when the Co-doped form Co0.15Mn0.85O1.84·0.6H2O is used. In that case, a constant capacity as high as 170 mAh g−1 can be maintained over more than 50 cycles with no change in the electrochemical behavior of the Co-doped sample.This clearly shows that stable capacity can be expected even from a hydrated oxide network. [Copyright &y& Elsevier]

Anisotropic temperature dependence of the electrical resistivity in LiCoO2 has been first clarified using chemically and structurally characterized single crystal specimens. The resistivities both perpendicular and parallel to the c-axis show semiconductive behavior with large anisotropy of ρc/ρa≈500 at 300 K. The temperature dependence of in-plane resistivity suggested a variable range hopping in the two-dimensional system. [ABSTRACT FROM AUTHOR]

The inorganic ion-exchanger α-zirconium phosphate was synthesized by the sol-gel method and its properties relating to the exchange of Cd2+ and the intercalation of CdS particles were studied. The Cd2+-exchange process is a fast process and the material obtained exhibits an increased interlayer distance d with respect to its precursor (9.56 vs. 7.56 Å). The resulting Cd-containing material was exposed to aH2S gas flow to give CdS particles in the exchanger. The zirconium phosphate containing CdS particles still possesses a layered structure, with a pattern almost identical to that of the initial ion-exchanger precursor. Moreover, the material may exchange further Cd2+ and hence lead to a higher CdS particle content. The thermal behavior of this ion-exchangers containing Cd2+ or CdS particles was studied. [ABSTRACT FROM AUTHOR]

Results of the investigations of deintercalation process in intercalation compounds graphite-SbCl5 and graphite-ICl are presented. It was found that sample mass losses have a step character that testifies to the discrete transition from one stage of graphite intercalation compounds to another. The increase in the rate of heating breaks the step character of mass loss dependence on temperature and intensive mass losses occur without stage transitions. [ABSTRACT FROM AUTHOR]

Vacuum heating of the layered compounds of lithium-aluminium double hydroxide pillared with copper, cobalt, and nickel complexes of ethylenediamine tetraacetic acid (EDTA) was shown to give rise to composite materials containing in the lamellar aluminate matrix nanosized metal particles stable to oxidation. High-resolution electron microscopy (HREM), powder X-ray diffraction (XRD), and small-angle X-ray scattering (SAXS) were used to determine the morphology of the resulting products. Their magnetic properties were studied by magnetic weighing. [ABSTRACT FROM AUTHOR]

This work developed an innovative membrane based on the high-performance PEBAX®2533 (PEBA) block copolymer and particles of iron-based layered double hydroxide (LDH) (Mg 4 FeAl layer composition) intercalated with phytotherapeutic abietate anions (ABI); both guest and host species are active in the promotion of wound healing. The presence of conjugated double bonds in the ABI structure promotes chemical reactions confronting its stability. Hence, LDH can protect the phytochemical species and promote its modified release. Aiming the development of wound dressings, LDH-ABI particles were immobilized in a biocompatible polymer (PEBA) by simple casting method. All samples were characterized by X-ray diffraction (XRD), vibrational (infrared and Raman) spectroscopies, thermogravimetry analysis coupled to mass spectrometry (TGA-MS), elemental chemical analyses and, in the case of polymer composites, by mechanical tests. Although the intercalation of organic anions into iron-based LDH materials is challenging, ABI intercalation was successful and using one-pot method (coprecipitation at constant pH value), according to XRD data. Additionally, spectroscopic techniques indicated the integrity of the ABI chemical structure after intercalation. The sodium abietate (NaABI) salt and the PEBA_NaABI membrane were also prepared to evaluate the effect of LDH in the formulations. In vitro release assays in saline solution at 32 °C showed the release (or solubilization) of around 3 and 5 wt./wt% of the ABI amount from LDH and salt, respectively, after 10 h. Comparatively, ABI release from the PEBA_Mg 4 FeAl-ABI and PEBA_NaABI formulations was improved to 20 and 22 wt%, respectively. The improvement in ABI release profiles from the membranes was related to the decrease in particles aggregation and improved media permeation. LDH particles released bioactive Mg2+ cations in the saline solution and, unlike NaABI particles, also improved the mechanical performance of the polymer. Thus, PEBA_Mg 4 FeAl-ABI showed promising as a component of wound dressings. • Intercalation of the natural abietate anion (ABI) into LDH for the first time. • ABI was intercalated into Fe3+-LDH in appreciable amount and by one-pot method. • PEBAX®2533_LDH-ABI membrane was successfully prepared by casting method. • The dispersion LDH-ABI particles into PEBAX®2533 membrane enhanced ABI release. • LDH improved the mechanical performance of PEBAX®2533 membrane. [ABSTRACT FROM AUTHOR]

Layered hydroxide salts (LHS) are synthetic and natural materials with the general chemical composition M2+(OH) 2− x (A m −) x / m (M2+ is a divalent cation, normally Mg2+, Ni2+, Zn2+, Ca2+, Cd2+, Co2+or Cu2+, and (A m −) x / m · n H 2 O is a hydrated counter-ion). In most of the cases, the LHS structures are based on the modification of the layered magnesium hydroxide-like structure (brucite, Mg(OH) 2), in which part of the structural hydroxide groups (OH−) from the Mg2+centered octahedra sharing edges are replaced by water molecules or anions. This process creates a net positive charge in the layers, which needs to be compensated with the intercalation/grafting of hydrated anions. Despite LHS versatility and having great potential for academic and industrial applications due to the variable chemical compositions, structures, and properties, this material is less explored in the literature. In the present review, the structures of the majority of the LHS materials are described and their potential applications are discussed, emphasizing their usage as supports for metalloporphyrins and utilization in different catalytic reactions. [Display omitted] • Layered hydroxide salts (LHS), historical, definitions, uses and applications. • LHS, materials with variable chemical compositions, structures and properties. • LHS, synthetic and natural materials which can exchange anions and/or cations. • LHS as support for metalloporphyrins and application in different catalytic reactions. • LHS as potential materials for several academic and industrial applications. [ABSTRACT FROM AUTHOR]

The intercalations of anionic molecules and drugs in layered double hydroxides (LDHs) have been intensively investigated in recent years. Due to their properties, such as versatility in chemical composition, good biocompatibility, high density and protection of loaded drugs, LDHs seem very promising nanosized systems for drug delivery. In this work, we report the intercalation of S-allyl-mercapto-cysteine (SAMC), which is a component of garlic that is well-known for its anti-tumor properties, inside ZnAl-LDH (hereafter LDH) nanostructured crystals. In order to investigate the efficacy of the intercalation and drug delivery of SAMC, the intercalated compounds were characterized using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The increase in the interlayer distance of LDH from 8.9 Å, typical of the nitrate phase, to 13.9 Å indicated the intercalation of SAMC, which was also confirmed using FT-IR spectra. Indeed, compared to that of the pristine LDH precursor, the spectrum of LDH-SAMC was richly structured in the fingerprint region below 1300 cm−1, whose peaks corresponded to those of the functional groups in the SAMC molecular anion. The LDH-SAMC empirical formula, obtained from UV-Vis spectrophotometry and thermogravimetric analysis, was [Zn0.67Al0.33(OH)2]SAMC0.15(NO3)0.18·0.6H2O. The morphology of the sample was investigated using SEM: LDH-SAMC exhibited a more irregular size and shape of the flake-like crystals in comparison with the pristine LDH, with a reduction in the average crystallite size from 3 µm to about 2 µm. In vitro drug release studies were performed in a phosphate buffer solution at pH 7.2 and 37 °C and were analyzed using UV-Vis spectrophotometry. The SAMC release from LDH-SAMC was initially characterized by a burst effect in the first four hours, during which, 32% of the SAMC is released. Subsequently, the release percentage increased at a slower rate until 42% after 48 h; then it stabilized at 43% and remained constant for the remaining period of the investigation. The LDH-SAMC complex that was developed in this study showed the improved efficacy of the action of SAMC in reducing the invasive capacity of a human hepatoma cell line. [ABSTRACT FROM AUTHOR]

Poly(vinyl chloride) (PVC), an important thermoplastic polymer widely-used in various fields, requires the use of thermal stabilizers to enhance its thermal stability during polymer processing and practical applications because of the poor thermal stability. Layered double hydroxides (LDHs), two-dimensional anionic layered and versatile filler, are widely considered to be one kind of high-efficient and environment-friendly PVC thermal stabilizers. Interestingly, it is expected to gradually replace the traditional toxic thermal stabilizers such as lead salts. The recent development of LDH thermal stabilizers in PVC resins is here reviewed from four relevant aspects: - the thermal stabilization mechanism provided by LDHs, − the chemical composition of metal layers and - of interlayer guests, and - the dispersion state of LDH in PVC composites. The review provides a current picture to help in the choice of manufacturing of high-performance LDH thermal stabilizers. [ABSTRACT FROM AUTHOR]

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Electron diffraction through the c-face (layer planes) and scanning electron microscopy (SEM) on the a-face (perpendicular to the layer planes) have been used to study the intralayer crystal structure and the micro-structure of graphite and its intercalation compounds. With the electron diffraction technique, the intra-layer intercalate ordering and the associated order-disorder transformations have been studied in graphitealkali metals (K, Rb, Cs) and graphite-halogens Br, IBr, ICl). Reported here is the first observation of order-disorder transformations in the graphite-halogen compounds. Direct evidence is given for the presence of intralayer intercalate ordering in even extremely dilute lamellar and residue compounds. Also presented here is a new a-face surface preparation technique, which involves mechanical polishing and back-sputtering. SEM observations of the a-faces reveal large microstructural differences between highly-oriented pyrolytic graphite, chemically-separated single-crystal graphite and mechanically-separated single-crystal graphite. Significant exfoliation along the c-direction occurs upon intercalation. Evidence is given for the preferential trapping of intercalate at defects in both lamellar and residue compounds. [ABSTRACT FROM AUTHOR]

Inorganic ion-exchangers with a layered structure such as γ-zirconium and γ-titanium phosphates, intercalated with organic diamines, are able to exchange Pt2+ ions to give new intercalation compounds that can be utilized in heterogeneous catalysis. The experiments performed at different temperatures (25 and 45°C), show different ion uptakes, greater at 45°C and for the materials derived from γ-zirconium phosphate. After platinum exchange, all the materials show an amorphization in the XRD if compared with their precursors. The thermal behaviour of the platinum materials is specific, depending on the exchanger used and the ligand inside the exchanger. Pt2+ ion has a catalytic effect on ligand elimination in the γ-zirconium phosphate platinum compounds, but not in those derived from γ-titanium. All the obtained yellow materials show a small step in the TG curves and simultaneously we have the Pt2+→Pt0 reduction: this is confirmed by XRD registered at the temperatures of the thermal effect, showing peaks at dhkl=2.27 and 1.95 Å. [ABSTRACT FROM AUTHOR]

Better models to interpret physical properties as well as use of new preparative techniques have allowed in recent years the development of the predictive character of solid state chemistry. Various examples of this evolution have been given in this paper. It has been shown for instance that new materials (sometimes metastable ones) can be prepared, either by ion exchange or by chemical (or electrochemical) intercalation-deintercalation methods. The structural requirements of such reactions will be discussed. Another example is provided by the way one selects fast ionic conductors for energy storage. Various factors like amorphous nature, covalency, bond competition, presence of vacancies, influence of cationic lone pairs are discussed in the case of alkali ion or fluorine ion electrolytes. Attention is also paid to the stabilization of unusual electronic configurations, particularly for high oxidation states of transition elements, on the base of relevant structural and bonding considerations. In the field of magnetic properties, the possibility of obtaining new ferrimagnetic or ferromagnetic materials is discussed, as well as the ability to modify 1D-or 2D-behaviour of chain-or layer-type materials. Examples are also given showing how the performance of non-linear materials can be modified by playing with the factors determining structural distortions. Optical properties of materials are also strongly influenced by structural and bonding properties. It will be shown for instance how thanks to the relevant choice of a host, the lattice as well as the chemical composition of the material may lead to pure monochromatic 4 f UV emission in a Eu-doped material. Another example illustrates the possibility of obtaining a strong green emission in a[Ce, Tb]doped phosphate by choosing a formulation leading to best possible over-lapping of the Ce emission spectrum under appropriate UV illumination and the D → F excitation spectrum of Tb [ABSTRACT FROM AUTHOR]

In this work, we present a chemical vapor transport process involving the gaseous species DyAl 3 Cl 12 (g) in order to perform the intercalation of dysprosium trichloride into graphite. Even if it is known that such a reaction must be performed under chlorine atmosphere, this work reveals that an increase of the Cl 2 pressure in the synthesis reactor improves the intercalation yield. By combination of gravimetric measurement, EDX analysis and 00 l X-ray diffraction experiments, we evidence the synthesis of a novel 1st stage DyCl 3 -Graphite Intercalation Compound (GIC). The sample obtained in this study is a mixture of 1st stage DyCl 3 -GIC and 2nd stage AlCl 3 -GIC. However, considering the 1st stage DyCl 3 -GIC, the data collected in this work are in agreement with a I C repeat distance of 982 pm and a C 8.1 DyCl 3.9 formula. Along the c -axis, the intercalated sheet is three-layered and exhibits a Cl-Dy-Cl stacking sequence existing in pristine chloride. [Display omitted] • Chemical vapor transport is used for intercalation reaction (topotactic reactions). • A novel 1st stage DyCl 3 - graphite intercalation compound is obtained. • The intercalated sheet is a three-layered sandwich existing in pristine DyCl 3. [ABSTRACT FROM AUTHOR]

This work presents the development of multifunctional therapeutic membranes based on a high-performance block copolymer scaffold formed by polyether (PE) and polyamide (PA) units (known as PEBA) and layered double hydroxide (LDH) biomaterials, with the aim to study their uses as wound dressings. Two LDH layer compositions were employed containing Mg2+ or Zn2+, Fe3+ and Al3+ cations, intercalated with chloride anions, abbreviated as Mg-Cl or Zn-Cl, or intercalated with naproxenate (NAP) anions, abbreviated as Mg-NAP or Zn-NAP. Membranes were structurally and physically characterized, and the in vitro drug release kinetics and cytotoxicity assessed. PEBA-loading NaNAP salt particles were also prepared for comparison. Intercalated NAP anions improved LDH–polymer interaction, resulting in membranes with greater mechanical performance compared to the polymer only or to the membranes containing the Cl-LDHs. Drug release (in saline solution) was sustained for at least 8 h for all samples and release kinetics could be modulated: a slower, an intermediate and a faster NAP release were observed from membranes containing Zn-NAP, NaNAP and Mg-NAP particles, respectively. In general, cell viability was higher in the presence of Mg-LDH and the membranes presented improved performance in comparison with the powdered samples. PEBA containing Mg-NAP sample stood out among all membranes in all the evaluated aspects, thus being considered a great candidate for application as multifunctional therapeutic dressings. [ABSTRACT FROM AUTHOR]

The series of 2D solids, Fe(3XPy) 2 [Fe(CN) 5 NO] with 3X ​= ​3-Fluoro, 3-Chloro, 3-Bromo, 3-Iodo and Py ​= ​Pyridine, was obtained by intercalation of the organic molecule (3XPy) between neighboring layers of 2D ferrous nitroprusside. The organic ligand was found coordinated to the axial positions for the iron atom linked at the equatorial N ends of the CN groups in the nitroprusside building block, [Fe(CN) 5 NO]. The axial CN and NO ligands remain unlinked and contribute to the solid stability through attractive dipole-dipole interactions. The formed hybrid solids preserve the 2D nature because no chemical bond is established between neighboring organic molecules in the interlayer region. For X ​= ​F, a thermal induced spin transition was observed, but not for the remaining derivatives. The nature of such behavior is discussed according to the recorded XRD, Raman and Mössbauer data and computational calculations. The spin crossover transition in Fe(3FPy) 2 [Fe(CN) 5 NO] is an incomplete process, a sample fraction of about 50% remains in paramagnetic state, even at 5 ​K. The spin transition is accompanied of an atypical small structural change, corresponding to a variation of 0.7% for the unit cell volume. Such behavior finds explanation in both, the bonding properties of the N end of the CN ligands in the nitroprusside pseudo-octahedral block, and in the intermolecular interactions in the interlayer region. Thermal induced spin crossover behavior for Fe(3F-pyridine) 2 [Fe(CN) 5 NO]. Such behavior was not observed for the analogues of Cl, Br, I, which was ascribed to the involved intermolecular interactions in the interlayer region. Image 1 • Thermal induced spin transition in a series of hybrid inorganic-organic 2D solids. • Intercalation of organic molecules in layered transition metal nitroprussides. • Spin crossover transition in 2D ferrous nitroprusside. • Effect of the intermolecular interactions on the spin crossover transition. • A combined Mössbauer, Raman, DSC and magnetic study of spin crossover transition. [ABSTRACT FROM AUTHOR]

Lithium batteries are electrochemical devices that are widely used as power sources. This history of their development focuses on the original development of lithium-ion batteries. In particular, we highlight the contributions of Professor Michel Armand related to the electrodes and electrolytes for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

• Composition of graphite fluoride C 2 F x is controlled by changing the ratio BrF 3 /Br 2 in reaction. • The size of sp2 carbon regions increases with the decrease of x in C 2 F x. • Replacement of guest molecules in C 2 F x has little effect on the matrix properties. • Br 2 guests in C 2 F x are difficultly substitutable for CH 3 CN when x < 0.5. The interaction of graphite with a gaseous mixture of BrF 3 and Br 2 at room temperature produced fluorinated graphite intercalation compounds with bromine. By changing the concentration of BrF 3 in Br 2 from 6.2 to 2.9 % we were able to obtain matrices of fluorinated graphene layers (C 2 F x) n with x = 0.76, 0.66, 0.35, 0.25. It was shown that bromine was completely replaced by acetonitrile in the (C 2 F x) n with x > 0.6, while two types of guests (CH 3 CN and Br 2) were present between the layers with the lower fluorine loading. The Van der Waals forces hold CH 3 CN molecules in the (C 2 F x) n host. The interaction of Br 2 molecules with sp2 -carbon regions remained in the C 2 F x layers has donor-acceptor type. The models of guest molecules packing in host matrices (C 2 F x) n are considered using the data on the stoichiometry and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The electronic band structures of 1T-TiTe2 and Fe0.25TiTe2 have been clarified by angle-resolved resonant-photoemission spectroscopy. Upon Fe intercalation, while most of the band structure is unchanged, two new flat bands appear at the Fermi level and at E∼-0.5 eV. Constant-initial-state spectra indicate that these states are derived from both Ti 3d and Fe 3d states. While the Fermi wave number of the electron pocket around M point is reduced by Fe intercalation, those of hole pockets around Γ point are almost unchanged, suggesting that the additional electrons are accommodated by the new flat band at -0.5 eV. [Copyright &y& Elsevier]

Taking into account the oxidant properties of vanadium (V) compounds, the lamellar matrix VOPO4·2H2O is used as an oxidant agent towards aniline, giving as product an VOPO4–polyaniline intercalation compound of formula VOPO4·(C6H4N)1.1, which exhibits an interlayer distance of 1.6 nm. The SEM micrographs obtained for the VOPO4–Pani hybrid matrix shows that the microstructure of VOPO4·2H2O is changed after reaction, with a total exfoliation of the oxovanadium matrix, as well as a decrease of the crystallite grain sizes. [Copyright &y& Elsevier]

Transport properties of doped nanotube-based double junctions forming a nanotransistor are investigated within the tight binding formalism. The effects of doping, gate length and gate-source hopping have been considered. It is found that in addition to the importance of rotational symmetry in determining transport properties, large gains can be achieved for semiconducting doped tubes. [ABSTRACT FROM AUTHOR]

Material growth by van der Waals epitaxy has the potential to isolate monolayer (ML) materials and synthesize ultrathin films not easily prepared by exfoliation or other growth methods. Here, the synthesis of the early transition metal (Ti, V, and Cr) tellurides by molecular beam epitaxy (MBE) in the mono- to few-layer regime is investigated. The layered ditellurides of these materials are known for their intriguing quantum- and layer dependent- properties. Here we show by a combination of in situ sample characterization and comparison with computational predictions that ML ditellurides with octahedral 1T structure are readily grown, but for multilayers, the transition metal dichalcogenide (TMDC) formation competes with self-intercalated compounds. CrTe 2 , a TMDC that is known to be metastable in bulk and easily decomposes into intercalation compounds, has been synthesized successfully in the ML regime at low growth temperatures. At elevated growth temperatures or for multilayers, only the intercalation compound, equivalent to a bulk Cr 3 Te 4 , could be obtained. ML VTe 2 is more stable and can be synthesized at higher growth temperatures in the ML regime, but multilayers also convert to a bulk-equivalent V 3 Te 4 compound. TiTe 2 is the most stable of the TMDCs studied; nevertheless, a detailed analysis of multilayers also indicates the presence of intercalated metals. Computation suggests that the intercalation-induced distortion of the TMDC-layers is much reduced in Ti-telluride compared to V-, and Cr-telluride. This makes the identification of intercalated materials by scanning tunneling microscopy more challenging for Ti-telluride. The identification of self-intercalation compounds in MBE grown multilayer chalcogenides may explain observed lattice distortions in previously reported MBE grown early transition metal chalcogenides. On the other hand, these intercalation compounds in their ultrathin limit can be considered van der Waals materials in their own right. This class of materials is only accessible by direct growth methods but may be used as "building blocks" in MBE-grown van der Waals heterostructures. Controlling their growth is an important step for understanding and studying the properties of these materials.

Ion-exchange interaction of the monolayer aqueous dispersion obtained by hydration of crystalline LiMoS with Li, Na, K salts and alkyiammoniiim halides is studied. Intercalation compounds of MoS with hydrated inorganic cations as well as hitherto unattainable intercalation compounds of MoS with alkylammonium cations are shown to be formed under these conditions. The composition and structure of these compounds are investigated. [ABSTRACT FROM AUTHOR]