Laser-Induced Interdigital Structured Graphene Electrodes Based Flexible Micro-Supercapacitor for Efficient Peak Energy Storage

The rapidly developing demand for lightweight portable electronics has accelerated advanced research on self-powered microsystems (SPMs) for peak power energy storage (ESs). In recent years, there has been, in this regard, a huge research interest in micro-supercapacitors for microelectronics application over micro-batteries due to their advantages of fast charge–discharge rate, high power density and long cycle-life. In this work, the optimization and fabrication of micro-supercapacitors (MSCs) by means of laser-induced interdigital structured graphene electrodes (LIG) has been reported. The flexible and scalable MSCs are fabricated by CO₂-laser structuring of polyimide-based Kapton ^® HN foils at ambient temperature yielding interdigital LIG-electrodes and using polymer gel electrolyte (PGE) produced by polypropylene carbonate (PPC) embedded ionic liquid of 1-ethyl-3-methyl-imidazolium-trifluoromethansulphonate [EMIM][OTf]. This MSC exhibits a wide stable potential window up to 2.0 V, offering an areal capacitance of 1.75 mF/cm² at a scan rate of 5.0 mV/s resulting in an energy density (E_a) of 0.256 µWh/cm² @ 0.03 mA/cm² and power density (P_a) of 0.11 mW/cm² @0.1 mA/cm². Overall electrochemical performance of this LIG/PGE-MSC is rounded with a good cyclic stability up to 10,000 cycles demonstrating its potential in terms of peak energy storage ability compared to the current thin film micro-supercapacitors.     

1,3‐Bis[2‐(2‐hydroxybenzylideneamino)phenoxy]propane

The title compound {systematic name: 2,2′‐[1,3‐propanediyldioxydi‐o‐phenylenebis(nitrilomethylidyne)]diphenol}, C₂₉H₂₆N₂O₄, exists as the phenol–imine form in the crystal, and there are strong intramolecular O—H⋯N hydrogen bonds, with O⋯N distances of 2.545 (2) and 2.579 (2) Å. The C=N imine bond distances are in the range 1.276 (2)–1.279 (2) Å and the C=N—C bond angles are in the range 123.05 (16)–124.64 (17)°. The configurations about the C=N bonds are anti (1E).     

Structure-Activity Relationship of NF023 Derivatives Binding to XIAP-BIR1

Inhibitors of Apoptosis Proteins (IAPs) are conserved E3-ligases that ubiquitylate substrates to prevent apoptosis and activate the NF-kB survival pathway, often deregulated in cancer. IAPs-mediated regulation of NF-kB signaling is based on the formation of protein complexes by their type-I BIR domains. The XIAP-BIR1 domain dimerizes to bind two TAB1 monomers, leading to downstream NF-kB activation. Thus, impairment of XIAP-BIR1 dimerization could represent a novel strategy to hamper cell survival in cancer. To this aim, we previously reported NF023 as a potential inhibitor of XIAP-BIR1 dimerization. Here we present a thorough analysis of NF023 binding to XIAP-BIR1 through biochemical, biophysical and structural data. The results obtained indicate that XIAP-BIR1 dimerization interface is involved in NF023 binding, and that NF023 overall symmetry and the chemical features of its central moiety are essential for an efficient interaction with the protein. Such strategy provides original hints for the development of novel BIR1-specific compounds as pro-apoptotic agents.     

Physicochemical properties affecting lipofection potency of a new series of 1,2-dialkoylamidopropane-based cationic lipids

The in vitro transfection activity of a novel series of N,N'-diacyl-1,2-diaminopropyl-3-carbamoyl-(aminoethane) derivatives was evaluated against a mouse melanoma cell line at different +/- charge ratios, in the presence and absence of helper lipids. Only the unsaturated derivative N,N'-dioleoyl-1,2-diaminopropyl-3-carbamoyl-(aminoethane), (1,2lmp[5]) mediated significant increase in the reporter gene level which was significantly boosted in the presence of DOPE peaking at +/- charge ratio of 2. The electrostatic interactions between the cationic liposomes and plasmid DNA were investigated by gel electrophoresis, fluorescence spectroscopy, dynamic light scattering and electrophoretic mobility techniques. In agreement with the transfection results, 1,2lmp[5]/DOPE formulation was most efficient in associating with and retarding DNA migration. The improved association between the dioleoyl derivative and DNA was further confirmed by ethidium bromide displacement assay and particle size distribution analysis of the lipoplexes. Differential scanning calorimetry studies showed that 1,2lmp[5] was the only lipid that exhibited a main phase transition below 37 degrees C. Likewise, 1,2lmp[5] was the only lipid found to form all liquid expanded monolayers at 23 degrees C. In conclusion, the current findings suggest that high in vitro transfection activity is mediated by cationic lipids characterized by increased acyl chain fluidity and high interfacial elasticity.     

Synthesis and spectroscopy of an oligophenyl based cruciform with remarkable pi-pi assisted folding

A facile route has been developed for the preparation of a new family of oligophenyls based on a 2,5,2',5'-tetra-aryl substituted biphenyl structural motif. The cruciform terphenyl dimer 2,5,2',5'-tetra(4-tert-butylphenyl)-1,1'-biphenyl () has been prepared in a two step protocol as a representative of this interesting class of materials. The thermal behaviour of the cruciform was analysed by DSC and shows that forms an amorphous glass when cooled from the isotropic melt. Subsequent heating reveals a glass transition temperature at 130 degrees C. X-Ray single crystal structure analysis of 2,2'-bis(4-tert-butylphenyl)-1,1'-biphenyl () and shows that both these molecules with a quater-phenyl substructure adopt a folded solid-state structure. Examining the (1)H NMR spectra of and reveals that the interactions that induce this folding in the solid-state are sufficiently strong to bias foldamer formation also in solution. Consequently, it is reasonable to assume that the folded conformation within the lattice is due to intramolecular pi-pi interaction rather than being imposed by crystal packing. The optical properties of the cruciform terphenyl dimer are discussed relative to the linear analogue 1,4-bis(4-tert-butylterphenyl)benzene ().     

Seed-directed synthesis of zeolites with enhanced performance in the absence of organic templates

We demonstrate here a seed-directed synthesis (SDS) of Beta, Levyne, and Heulandite zeolites in the absence of organotemplates, where the seeds drive crystallization of the zeolites. Compared with conventional Beta synthesized in the presence of organic templates, Beta-SDS exhibits large textural parameters, stable Al species, and unprecedentedly high density of active sites, resulting in superior catalytic activity and selectivity for valuable products in catalysis.     

Spectral and photophysical studies on cruciform oligothiophenes in solution and the solid state

The photophysical and spectroscopic properties of a new class of oligothiophene derivatives, designated as cruciform oligomers, have been investigated in solution (room and low temperature) and in the solid state (as thin films in Zeonex matrixes). The study comprises absorption, emission, and triplet-triplet absorption spectra, together with quantitative measurements of quantum yields (fluorescence, intersystem crossing, internal conversion, and singlet oxygen formation) and lifetimes. The overall data allow the determination of the rate constants for all decay processes. From these, several conclusions are drawn. First, in solution, the main deactivation channels for the compounds are the radiationless processes: S(1) --> S(0) internal conversion and S(1) --> T(1) intersystem crossing. Second, in general, in the solid state, the fluorescence quantum yields decrease relative to solution. A comparison is made with the analogous linear alpha-oligothiophenes, revealing a lower fluorescence quantum efficiency and, in contrast to the normal oligothiophenes, that internal conversion is an important channel for the deactivation of the singlet excited state. Replacement of thiophene by 1,4-phenylene units in the longer-sized cruciform oligomer increases the fluorescence efficiency. The highly efficient generation of singlet oxygen through energy transfer from the triplet state (S(Delta) approximately 1) provides support for the measured intersystem crossing quantum yields and suggests that reaction with this may be an important pathway to consider for degradation of devices produced with these compounds.     

Phosphorus-nitrogen compounds. Part 13. Syntheses, crystal structures, spectroscopic, stereogenic, and anisochronic properties of novel spiro-ansa-spiro-, spiro-bino-spiro-, and spiro-crypta phosphazene derivatives

The condensation reactions of N2Ox (x = 2, 3) donor-type aminopodand (4) and dibenzo-diaza-crown ethers (5, 6, and 9) with hexachlorocyclotriphosphazatriene, N3P3Cl6, produce two kinds of partially substituted novel phosphazene derivatives, namely, spiro-bino-spiro- (19) and spiro-crypta (21, 22, and 25) phosphazenes. The partially substituted spiro-ansa-spiro-phosphazene (11) reacted with pyrrolidine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) give the corresponding new fully substituted phosphazenes (14 and 16). Unexpectedly, the reactions of 23 and 24 with pyrrolidine result in only geminal crypta phosphazenes (26 and 27). The solid-state structures of 16 and 22 have been determined by X-ray diffraction techniques. The relative inner hole-size of the macrocycle in the radii of 22 is 1.27 A. The relationship between the exocyclic NPN (alpha') and endocyclic (alpha) bond angles for spiro-crypta phosphazenes and exocyclic OPN (alpha') bond angles for spiro-ansa-spiro- and spiro-bino-spiro-phosphazenes with 31P NMR chemical shifts of NPN and OPN phosphorus atoms, respectively, have been investigated. The structures of 10, 14, 16, 19, 21, 22, and 25-27 have also been examined by FTIR, 1H, 13C, and 31P NMR, HETCOR, MS, and elemental analyses. The 31P NMR spectra of 10, 21, 22, and 25 indicate that the compounds have anisochrony. In compounds 16 and 22, the spirocyclic nitrogen atoms have pyramidal geometries resulting in stereogenic properties.