Interactions In Solid State Research Articles

Experimental and theoretical studies of palladium(II) and platinum(II) complexes derived from di-(2-pyridyl)methyl-N,N′-dibenzyldithiocarbamate

Di-(2-pyridyl)methyl-N,N′-dibenzyldithiocarbamate (L) and their metal complexes of formula [MII(L)Cl2], M = Pd (1); M = Pt, (2), and [PdII(L)2](BF4)2 (3) were synthesized and characterized in solution and in solid state by NMR, elemental analysis and vibrational spectroscopy, respectively. The crystal structures of the 1, 2, and 3 were stablished by X-ray single crystal diffraction. In all complexes, the molecular structures displayed the formation of six-membered chelate rings with a square planar local geometry around the MII cations. The N,N′-dibenzyldithiocarbamate group is located in a flagpole position, enhancing the formation of intramolecular M⋯S interactions in solid state. The nature of the M⋯S and CH⋯S interactions in complexes 1–3 was analyzed by means of density functional methods.

Study the effect of gamma Irradiation on the Superconducting Properties of HgBaSrCa2Cu3O8+δ

In this work, goal is to study the effect of gamma irradiation on the properties of superconducting of the superconductor HgBaSrCa2Cu3O8+δ, at room temperature using a source of 137Cs with a dose of 3. 6 and 9 MRad. The sample was prepared through solid state interaction. The properties of superconductor and XRD were studied before and after irradiation. It appears that our compound has a quadratic structure corresponding to the 1223 phase with a low c / a ratio due to gamma irradiation. Moreover, the transition temperature (Tc (on) & Tc (off)) decreased from 113 to 105 K and 119 to 114 K, respectively, when the dose increased from 0 to 9 Mrad.

M‐Nitrocinnamic Acid Containing Lipophilic Peptide Exhibits Selective Growth Inhibition Activity against Leishmania major

AbstractA series of peptides (1‐3) containing m‐nitrocinnamic acid, α‐aminoisobutyric acid (Aib) and L‐leucine has been synthesized and their antileishmanial propensities have been studied. The compound 1 was synthesized by condensation reaction of 3‐nitrobenzaldehyde and malonic acid. The compound 1 forms duplex by intermolecular hydrogen bonding interactions in solid state and finally self‐assemble to form supramolecular helix through C‐H⋅⋅⋅O hydrogen bonds. The peptide 2 shows antiparallel sheet‐like assembly through intermolecular N‐H⋅⋅⋅O and C‐H⋅⋅⋅O hydrogen bonding interactions. The peptide 3 adopts extended conformation and self‐assemble to form bowl‐like morphology. Moreover, the peptide 3 exhibits significant growth inhibition property on Leishmania major promastigotes with an IC50 value of 13 μg/ml. But compound 1 and peptide 2 have IC50 values 100 μg/ml and 41 μg/ml respectively. The higher lipophilicity of peptide 3 may increase the chances of reaching this intracellular parasite. Thus peptide 3 shows selective toxicity towards Leishmania (IC50=13 μg/ml) and compared to several existing standard antileishmanial drugs like pentastam (IC50 > 64 μg/ml), sodium stibogluconate (IC50 > 64 μg/ml) or ketoconazole (IC50=72 μg/ml), peptide 3 shows at least 2–6 times higher potency.

Mechanochemical synthesis of nanocomposites based on Fe3O4 and layered double hydroxides

Magnetic composites Fe3O4/layered double hydroxides (LDH) with a molar ratio of Fe3O4/LDH=1 were synthesized using the “soft” mechanochemical processing. The molar ratio M2+/Fe3+ (M2+ is Mg or Ni) in LDH was 2, 3 and 4. The synthesis was carried out in a mortar via the solid-state interaction between NaOH and salts mixtures containing the components necessary for the synthesis of both Fe3O4 and LDH. The feature of the proposed method is the simultaneous formation of the magnetic constituent Fe3O4 and the LDH phase in the reaction medium. The sorption properties of the obtained materials towards As(III) were investigated

Structure and strength of the interfacial zone in solid-phase contact interaction of diamond with transition metals

The features of intermediate layers formed as a result of solid phase contact interaction of diamond with carbon-reactive metals— chromium, cobalt, iron and titanium, were studied under temperature-time mode corresponding to the sintering of copper-impregnated cemented carbide matrices of diamond tools. The structural-phase state of the diamond-metal transition zone was studied by scanning electron microscopy, X-ray diffraction methods and Raman spectroscopy. The diamond-metal bond strength was determined by shear testing. It was found that a metal-carbide coating to diamond and consisting of the interacting metal, carbide phases, traces of oxide and graphite, with different bonding strength to diamond is formed at the transition zone during solid-state contact interaction of diamond with transition metals. The formation of a durable metal-carbide layer, essentially a metallized coating, during the contact interaction of diamond with iron and chromium can be used in the development of technology that provides an increased level of diamond retention in the cemented carbide matrix composites.

Fluorination-Induced Evolution of Columnar Packing in Fluorous Triphenylenes and Benzotriphenylenes.

Use of D3h -symmetrical triphenylene (TRPH) as a substrate for high-temperature radical reactions with C4 F8 I2 under varying conditions resulted in the introduction of four types of fluorinated substituents: ω-C4 F8 H, c-C4 F8 , c-C4 F4 , and c-C4 HF3 . In contrast to the previous work on direct (poly)substitutions with RF groups in polycyclic aromatic hydrocarbons (PAHs), in this work regiospecificity, selectivity, and high yield were achieved for TRPH(C4 F8 ) and TRPH(C4 F8 )3 . New single-crystal structural data for seven compounds combined with literature crystallographic data allowed for the first detailed and precise analysis of the effects of fluorous substituent types, their number, and their position(s) on the TRPH core on the solid-state packing, and more specifically, the degree of π-π overlap between neighboring molecules, which is linked to charge transport properties. Comparison of isostructural partially fluorinated benzotriphenylenes, 2,3-TRPH(C4 F4 ) and 2,3-TRPH(C4 HF3 ), revealed an unexpectedly large (30 %) drop of π-π overlap, when only one fluorine atom was replaced with the hydrogen atom in a C4 F4 moiety. Theoretical and potentially practical implications of this work may include further testing and elaboration of computational methods describing solid-state interactions and predictions of transport properties of organic semiconductors, and further advances in the molecular design of high-performing TRPH-based organic materials and supramolecular architectures for organic optoelectronics.

Photoluminescence of platinum(II) diethynylphenanthroline organometallic complexes with bis-arylethynyl derivatives in solution and solid state

Platinum(II) phenanthroline organometallics, Pt(3,8-Phen≡H)(≡Ph-R)2 (1H–11H), of 11 respective arylethynyl ligands with different substituents: R = H (1H), 4-F (2H), 3-F (3H), 2-F (4H), 4-Me (5H), 4-CF3 (6H), NO2 (7H), 4-COOMe (8H), 4-t-Bu (9H), 3,5-di-CF3 (10H), and 3,5-di-t-Bu (11H) were prepared from our reported complexes, Pt(3,8-Phen≡TMS)(≡Ph-R)2, by a deprotection reaction of a trimethylsilyl group. The luminescence and the DFT calculations of the 11 present organometallics clearly supported the assignment of phosphorescence from the mixed transition of 3MLCT/3LLCT (LLCT = ligand-to-ligand charge transfer) in solution state. In solid state, the emission maximum peak values in the spectra of many complexes in 22 platinum organometallics occurred in the long wavelength area over 700 nm, and their emissions were assigned the phosphorescence from the transition of a metal-metal-to-ligand charge transfer, the so-called 3MMLCT. This is related to the diversity of intermolecular interactions as Pt-Pt and π-π interactions in solid state. On the other hand, the emission peak values in the spectra of some complexes occurred in the short-wavelength area less than 600 nm. The complex Pt(3,8-Phen≡TMS)(≡Ph-3,5-di-CF3)2 showed a particularly strong and vibronic emission, and this phenomenon is presumed to be attributable to the aggregation-induced emission.

New hypercoordinated diorganotin(IV) compounds with dithiocarbamato ligands. Synthesis and structural characterization

Several homo- and heteroleptic diorganotin(IV) dithiocarbamato halides of type RR'Sn(S2CNR″2)Cl [R = R' = Me, R'' = Me (1), Et (2); R = R' = nBu, R'' = Me (3), Et (4); R = 2-(Me2NCH2)C6H4, R' = Me, R'' = Me (5), Et (6)] and pseudo-halides of type RR'Sn(S2CNR″2)(NCS) [R = R' = Me, R'' = Me (7), Et (8); R = R' = nBu, R'' = Me (9), Et (10); R = 2-(Me2NCH2)C6H4, R' = Me, R'' = Me (11), Et (12); R' = nBu, R'' = Et (13), R' = 2-(Me2NCH2)C6H4, R'' = Me (14), Et (15)] were prepared by salt metathesis reactions, starting from either RR'SnCl2 or RR'Sn(NCS)2. In all compounds the dithiocarbamato ligand acts as a bidentate moiety. For the compounds 11–15, as well as for the species 5 and 6, of type RR'Sn(S2CNR″2)Cl, bearing aromatic groups with pendant arms attached to tin, the NMR spectra gave no clear evidence for a N→Sn coordination in solution at room temperature. The molecular structures determined by single-crystal X-ray diffraction for compounds 12 and 14, with one or two 2-(Me2NCH2)C6H4 groups, respectively, revealed the existence of intramolecular N→Sn interactions in solid state. The IR spectra suggest an isothiocyanato behavior of the NCS group in solid state in all cases, while the 119Sn NMR spectra gave no clear evidence for such a behavior in solution, as no 14N-119Sn couplings were observed. The single-crystal X-ray diffraction studies revealed molecular species for 7, 8 and 12, while 14 is a ionic compound with [{2-(Me2NCH2)C6H4}2Sn(S2CNMe2)]+ cations and SCN− anions.

The formation of disordered intermetallic phase during the solid-state interaction of WC with Ir

A relatively simple approach based on mixing WC and iridium powders, followed by heating to 1300–1600 °C in inert atmosphere, was proposed to synthesize refractory intermetallics in the tungsten – iridium system. The peculiarities of the solid-state interaction in the WC-Ir system were studied within the 1000–1600 °C temperature range using a set of modern analytical techniques. Intensive solid-state interaction in the WC – Ir system starts at 1300 °C. It was stated that this interaction can be described by two stages in the 1300–1600 °C temperature range. The first stage is the formation of Ir-rich disordered WxIr1-x solid solution with constant average composition W0.265Ir0.735. The second stage is the interaction of the obtained WxIr1-x solid solution with residual component (Ir or WC) that leads to the shift of the WxIr1-x phase composition on one side or the other in dependence on type of residual component. No ordered intermetallic phases are formed in the 1300–1600 °C temperature range. In the course of the solid-state reaction, free carbon is released as graphite-like phase on the surface of the intermetallic product.

A solution-processed small molecule with optimal side chains for high efficiency non-fullerene organic solar cells

A novel small molecular electron donor with an optimized side group was synthesized for solution-processed organic solar cells. In order to extend the conjugation length in 2-dimensional structure, 5-alkylthio-thieno[3,2-b]thiophene was attached onto the central benzo[1,2-b:4,5-b’]dithiophene unit. The small molecule exhibited an optical energy gap of 1.71 eV, low-lying energy levels, strong intermolecular interaction in solid state, which result in promising power conversion efficiency up to 7.15% with ITIC as a non-fullerene electron acceptor. This work demonstrates the potential of optimal side chain of small molecular donor for high performance of solution-processed non-fullerene organic solar cells.

Direct observation of electron density reconstruction at the metal-insulator transition in NaOsO3

The $5d$ transition-metal oxides offer further opportunities to test our understanding of the interplay of correlation effects and spin-orbit interactions in materials in the absence of a single dominant interaction. The subtle balance between solid-state interactions can result in mechanisms that minimize the interaction energy, and in material properties of potential use for applications. We focus here on the $5d$ transition-metal oxide $\mathrm{NaOs}{\mathrm{O}}_{3}$, a strong candidate for the realization of a magnetically driven transition from a metallic to an insulating state exploiting the so-called Slater mechanism. Experimental results are derived from nonresonant and resonant x-ray single-crystal diffraction at the Os $L$ edges. A change in the crystallographic symmetry does not accompany the metal-insulator transition in the Slater mechanism and, indeed, we find no evidence of such a change in $\mathrm{NaOs}{\mathrm{O}}_{3}$. An equally important experimental observation is the emergence of the (300) Bragg peak in the resonant condition with the onset of magnetic order. The intensity of this space-group-forbidden Bragg peak continuously increases with decreasing temperature in line with the square of intensity observed for an allowed magnetic Bragg peak. Our main experimental results, the absence of crystal symmetry breaking, and the emergence of a space-group-forbidden Bragg peak with developing magnetic order, support the use of the Slater mechanism to interpret the metal-insulator transition in $\mathrm{NaOs}{\mathrm{O}}_{3}$. We successfully describe our experimental results with simulations of the electronic structure and with an atomic model based on the established symmetry of the crystal and magnetic structure.

One-step preparation of TaIr3-based material and its ablation performance under extreme environmental conditions

The solid-state interaction of TaC with Ir within the 1000–1600 °C temperature range leads to the formation of TaIr3 intermetallics. The durability of the TaIr3-based system with a silicon additive was studied under extreme environmental conditions. The TaIr3-based material displays satisfactory ablation resistance at 2000 °C in air in arc-jet. The post-test microstructural and XRD analysis of the developed material allowed us to propose the role of different constituents of the Ta – C – Ir – Si system. The iridium-containing phases play the most significant role in favorable ablation behavior of the developed system.

Delivery of deep-sourced, volatile-rich plume material to the global ridge system

The global mid-ocean ridge (MOR) system represents a major site for outgassing of volatiles from Earth's mantle. The amount of H2O released via eruption of mid-ocean ridge basalts varies along the global ridge system and greatest at sites of interaction with mantle plumes. These deep-sourced thermal anomalies affect approximately one-third of all MORs – as reflected in enrichment of incompatible trace elements, isotope signatures and elevated ridge topography (excess melting) – but the physical mechanisms involved are controversial. The “standard model” involves solid-state flow interaction, wherein an actively upwelling plume influences the divergent upwelling generated by a mid-ocean ridge so that melting occurs at higher pressures and in greater amounts than at a normal spreading ridge. This model does not explain, however, certain enigmatic features including linear volcanic ridges radiating from the active plume to the nearby MOR. Examples of these are the Wolf–Darwin lineament (Galápagos), Rodrigues Ridge (La Réunion), Discovery Ridge (Discovery), and numerous smaller ridge-like structures associated with the Azores and Easter–Salas y Gómez hot spots. An important observation from our study is that fractionation-corrected MORB with exceptionally-high H2O contents (up to 1.3 wt.%) are found in close proximity to intersections of long-lived plume-related volcanic lineaments with spreading centres.New algorithms in the rare-earth element inversion melting (INVMEL) program allow us to simulate plume–ridge interactions by mixing the compositions of volatile-bearing melts generated during both active upwelling and passively-driven corner-flow. Our findings from these empirical models suggest that at sites of plume–ridge interaction, moderately-enriched MORBs (with 0.2–0.4 wt.% H2O) result from mixing of melts formed by: (i) active upwelling of plume material to minimum depths of ∼35 km; and (ii) those generated by passive melting at shallower depths beneath the ridge. The most volatile-rich MORB (0.4–1.3 wt.% H2O) may form by the further addition of up to 25% of “deep” small-fraction plume stem melts that contain >3 wt.% H2O. We propose that these volatile-rich melts are transported directly to nearby MOR segments via pressure-induced, highly-channelised flow embedded within a broader “puddle” of mostly solid-state plume material, spreading beneath the plate as a gravity flow. This accounts for the short wavelength variability (over 10s of km) in geochemistry and bathymetry that is superimposed on the much larger (many 100s of km) “waist width” of plume-influenced ridge.Melt channels may constitute a primary delivery mechanism for volatiles from plume stems to nearby MORs and, in some instances, be expressed at the surface as volcanic lineaments and ridges. The delivery of small-fraction hydrous melts from plume stems to ridges via a two-phase (melt-matrix) regime implies that a parallel, bimodal transport system is involved at sites of plume–ridge interaction. We estimate that the rate of emplacement of deep-sourced volatile-rich melts in channels beneath the volcanic lineaments is high and involves 10s of thousands of km3/Ma. Since mantle plumes account for more than half of the melt production at MORs our findings have important implications for our understanding of deep Earth volatile cycling.

Characterization of Inclusion Complexes between Miconazole and Different Cyclodextrin Derivatives

Abstract Objective: Miconazole, an imidazole antifungal derivative, is a very hydrophobic compound, a major drawback in obtaining topical pharmaceutical formulations with optimal bioavailability. Cyclodextrins (CDs) may increase local drug delivery by enhancing the drug release and/or permeation. The aim of the study is the characterization of inclusion complexes between miconazole and different CD derivatives. Methods: Several CD derivatives were tested in the experiments. The binary systems between miconazole and different CDs were prepared in 1:1 molar ratios by physical-mixture and kneading methods. Differential scanning calorimetry (DSC) and Fourier transformed-infrared spectroscopy (FT-IR) methods were used to characterize solid state interactions between miconazole and CDs in their binary systems. Results: The FT-IR analysis suggests the formation of a new solid phase, indicating a molecular interaction between the components. The DSC analysis sustains the hypothesis of formation of partial inclusion complexes between miconazole nitrate and CD. Conclusion: The thermic behaviour of the complexes depends both on the preparation method and the composition of the products.

New Ablation-Resistant Material Candidate for Hypersonic Applications: Synthesis, Composition, and Oxidation Resistance of HfIr3-Based Solid Solution.

The peculiarities of the solid-state interaction in the HfC-Ir system have been studied within the 1000-1600 °C temperature range using a set of modern analytical techniques. It was stated that the interaction of HfC with iridium becomes noticeable at temperatures as low as 1000-1100 °C and results in the formation of HfIr3-based substitutional solid solution. The homogeneity range of the HfIr3± x phase was evaluated and refined as HfIr2.43-HfIr3.36. The durability of the HfIr3-based system under extreme environmental conditions was studied. It was shown that the HfIr3-based material displays excellent ablation resistance under extreme environmental conditions. The benefits of the new designed material result from its relative oxygen impermeability and special microstructure similar to superalloys. The results obtained in this work allow us to consider HfIr3 as a very promising candidate for extreme applications.

The influence of the molecular packing on the room temperature phosphorescence of purely organic luminogens

Organic luminogens with persistent room temperature phosphorescence (RTP) have attracted great attention for their wide applications in optoelectronic devices and bioimaging. However, these materials are still very scarce, partially due to the unclear mechanism and lack of designing guidelines. Herein we develop seven 10-phenyl-10H-phenothiazine-5,5-dioxide-based derivatives, reveal their different RTP properties and underlying mechanism, and exploit their potential imaging applications. Coupled with the preliminary theoretical calculations, it is found that strong π–π interactions in solid state can promote the persistent RTP. Particularly, CS-CF3 shows the unique photo-induced phosphorescence in response to the changes in molecular packing, further confirming the key influence of the molecular packing on the RTP property. Furthermore, CS-F with its long RTP lifetime could be utilized for real-time excitation-free phosphorescent imaging in living mice. Thus, our study paves the way for the development of persistent RTP materials, in both the practical applications and the inherent mechanism.

Effects of Drying Process on an IgG1 Monoclonal Antibody Using Solid-State Hydrogen Deuterium Exchange with Mass Spectrometric Analysis (ssHDX-MS).

Lyophilization and spray drying are widely used to manufacture solid forms of therapeutic proteins. Lyophilization is used to stabilize proteins vulnerable to degradation in solution, whereas spray drying is mainly used to prepare inhalation powders or as an alternative to freezing for storing bulk drug substance. Both processes impose stresses that may adversely affect protein structure, stability and bioactivity. Here, we compared lyophilization with and without controlled ice nucleation, and spray drying for their effects on the solid-state conformation and matrix interactions of a model IgG1 monoclonal antibody (mAb). Solid-state conformation and matrix interactions of the mAb were probed using solid-state hydrogen-deuterium exchange with mass spectrometric analysis (ssHDX-MS), and solid-state Fourier transform infrared (ssFTIR) and solid-state fluorescence spectroscopies. mAb conformation and/or matrix interactions were most perturbed in mannitol-containing samples and the distribution of states was more heterogeneous in sucrose and trehalose samples that were spray dried. The findings demonstrate the sensitivity of ssHDX-MS to changes weakly indicated by spectroscopic methods, and support the broader use of ssHDX-MS to probe formulation and process effects on proteins in solid samples.

Enhanced solubility and drug release profile of boswellic acid using a poloxamer-based solid dispersion technique

Boswellic acids (BAs) a group of pentacyclic triterpenes have therapeutic activities. However, their lipophilic nature limits their aqueous solubility and thus bioavailability. Hence, present study aims to enhance solubility and dissolution of BA by solid dispersion (SD) technique using poloxamer (PXM) 188 and 407 as hydrophilic polymeric carriers. Effect of increasing concentration of PXMs on solubility of BAs was examined using phase solubility studies. The stability constants were 1667.5 M-1 (BA: PXM 188) and 3707.4 M-1 (BA: PXM 407) with an AL type curve. Negative Gibbs free energy (ΔGtr°) values indicated spontaneous nature of BA solubilization which decreased with increasing concentration of carrier demonstrating favorability of reaction. 1:1 and 1:2 SDs synthesized using kneading (KN) and solvent evaporation (SE) method were subjected to physicochemical characterization by FTIR and DSC to assess solid state interactions between BAs and PXMs that suggested interaction between carrier and BAs. Efficiency of PXMs was evaluated using saturated solubility and in vitro drug release studies. SDs of PXM 188 (1:2) and PXM 407(1:1) by KN showed highest solubility and drug release profile indicating ability of PXMs as solubility enhancers of BAs. Thus, SD technique helps improve the solubility and dissolution rate of poorly soluble BAs.

Phase formation during high-energy ball milling of the 33Al-45Cu-22Fe (at.%) powder mixture

The process of mechanical alloying in the 33Al-45Cu-22Fe (at.%) powder mixture subjected to high-energy ball milling was studied. Due to complexity of the alloy formation in this system, several methods – X-ray diffraction phase analysis, Differential Dissolution, thermal analysis and Transmission and Scanning Electron Microscopy – were combined to obtain the detailed information on the structure and composition of the mechanical alloying products. Possible formation mechanisms of these phases during mechanical alloying are discussed. No crystalline phase containing Fe and Cu, Al has been found in the products of mechanical alloying of the 33Al-45Cu-22Fe mixture. The formation of Cu-Al phases followed the sequence of Al2Cu → Al4Cu9 → Cu(Al) solid solution. When only those phases that were detected by the XRD analysis were taken into account, the mass balance of Al and Fe in the products of mechanical alloying was not satisfied. The Differential Dissolution and high-resolution Transmission Electron Microscopy data suggest the formation of non-stoichiometric X-ray amorphous phases containing all three elements. Reasons for the retardation of the solid-state interaction between aluminum and copper in the ternary powder mixture are discussed.

Intercalation of calcein into layered silicate magadiite and their optical properties.

Calcein–Ca (II), Zn (II) and Al (III) complexes were successfully intercalated into interlayer surfaces of layered silicate magadiite and fluorescence properties of organic metal-chelates in the confined spaces were investigated. Structures, compositions and morphologies of the intercalated magadiites were adequately studied by tests, including X-ray diffraction, energy-dispersive X-ray spectrometer, elemental mapping, X-ray photoelectron spectroscopy, inductively coupled plasma atomic emission spectroscopy, Fourier-transform infrared spectra, ultraviolet–visible spectroscopy, thermo-gravimetric analysis, differential thermal analysis and scanning electron microscopy. Results confirmed that metal–organic chelate species were immobilized onto the silicate sheets via solid-state interaction. Basal spacings between silicate layers decreased by exchanged metal ions and increased after intercalation of calcein into the interlayer spaces of cation-exchanged magadiites. The encapsulation was obtained by a flexible solid–solid reaction, and the present reaction and products had a potential of application to industrial uses. A speculative mechanism was proposed for reaction by solid-state intercalation. Furthermore, it was found that the complexes in the interlayer space also exhibited special fluorescence properties. The significance of this current work was that it provided a possible route for synthesizing metal–organic complexes that encapsulated in phyllosilicate.