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New ferrocenyl Schiff bases [Fc─C(H)═N─C 6 H 3 (OH)(R)] (R = H (1), NO 2 (2)) have been synthesized and characterized using various techniques. Compound 2 was further confirmed using single-crystal X-ray diffraction analysis.Solvatochromism studies of 2 showed redshift from nonpolar to polar solvents. In addition, results of fluorescence studies indicated excellent aggregationinduced emission properties. The quasi-reversible redox wave in electrochemical studies of the Schiff bases evidenced the electron transfer ability of ferrocene to the Schiff base (─C═N─) conjugation group. The second-order nonlinear optical (NLO) properties of 1 and 2 were investigated using the Kurtz-Perry powder technique and 2 showed an effect 1.46 times greater than that of urea reference. Although 2 crystallized in the P2 1 /c centrosymmetric space group, NLO property was observed, due to non-covalent interactions (C─H⋅⋅⋅π). The band gaps were calculated using the diffuse reflectance spectroscopic method and 2 exhibited a low band gap of 2.9 eV which is due to the more electronwithdrawing nature of the nitro group. Quantum chemical calculations were performed on the synthesized compounds using the density functional theory (DFT) and time-dependent DFT approach. The theoretical studies showed that the band gap for the Schiff bases was 3.8 eV (1) and 3.2 eV (2) and they can be considered as candidates for use in optical applications. KEYWORDS aggregation-induced emission (AIE), DFT/TD-DFT, electrochemical studies, ferrocenyl Schiff bases, nonlinear optics | INTRODUCTIONResearch on ferrocene-containing compounds has drawn immense attention due to their wide-ranging applications in the fields of catalysis, [1] sensors, [2] luminescent systems, [3] nonlinear optics [4a] and molecular electronic devices [5] due to their well-established redox switching abilities. [6] Since ferrocene displays a good electrochemical response because of its strong π-donating ability and good reversibility in one-electron oxidation at a desirable

In this study, we present the physicochemical, rheological, and dielectric properties of the superparamagnetic iron oxide nanoparticles (SPIONs) coated with polyethyleneglycol (PEG). It was observed that the increase of the concentration of PEG prohibited the sedimentation of nanoparticles, which increased the colloidal stability of nanocomposites. The surface study of the polymer and the nanocomposites using TOF-SIMS showed that the samples did not have the same surface properties. The analysis of the intensity ratios of the FeO + /Fe + and OH − /O − peaks of the nanocomposites of bare, positively, and negatively charged SPIONs with PEG revealed that no reduction occurred for these nanoparticles when coated with PEG, whereas the iron atoms on the surface of PEG negatively charged SPIONs were less oxidized than those on the surface of PEG-bare SPIONs, and the iron atoms on the surface of PEG positively charged SPIONs were more oxidized than the second ones. The rheological study of the polymer and the nanocomposites revealed that the presence of SPIONs did not change the rheological behavior of PEG. The analysis of the dielectric properties of PEG and its composites with SPIONs showed that when SPIONs particles (bare and positively charged) were included in PEG, low frequency dispersion (LFD) was strongly enhanced, that the iron oxide nanoparticles reduced the impedance of PEG in the nanocomposites and that the difference in their surface charge affected their impedance. Taken together, these results suggest that the nanocomposites of PEG with SPIONs have appropriate properties for fluid modification and applications in the nanotechnology and photovoltaic devices.

The electrical properties of epoxy based composites modified by low amounts of graphite oxide, below the conduction threshold, have been investigated. The composites have been prepared without the use of solvents by direct sonication of graphite oxide (GO) powders and of chemically modified and partially reduced GO powders in the based epoxy monomer. Through a mild thermal treatment, in situ reduction of the previously dispersed GO has been obtained directly inside the epoxy resins. The changes in the electrical response of the materials thus obtained have been compared to that of pristine unmodified epoxy resin. Data so far collected underline the possibility to tune the electrical conductivity of the composites within two orders of magnitude and to increase the values of permittivity without significantly worsening dielectric losses. POLYM. COMPOS., 36:294–301, 2015. © 2014 Society of Plastics Engineers

Novel Y-shaped ferrocene appended imidazole compounds with good quadratic hyperpolarizabilities as building blocks for composite polymeric films with a good second harmonic generation response.

As eries of new b-ketoimines containing af errocene moiety and their BF 2 complexes have been synthesized and structurally characterized. The solvatochromism of the b-ketoimines was studied, putting in evidencearedshift with increasing solvent polarity.T his positive solvatochromism can be attributed to am ore polarizede xcited state compared with the grounds tate, due to intramolecular charge transfer( ICT) transitions. The b-ketoimines exhibited weak emission, attributable to the excited-state intramolecular proton transfer( ESIPT) phenomenon. This ESIPT effect is suppressedu ponr estriction of the keto-enaminet automerism, inducedu pon addition of BF 3 •OEt 2 ,w hich afforded the related BF 2 complexes, characterized by an enhancement of the fluorescence through the ICT effect. Both the b-ketoimines and BF 2 complexes exhibited significant aggregation-inducede mission behavior in mixtureso fC H 3 CN/H 2 O, due to restriction of intramolecular rotationint he aggregated state. The frontier molecular orbital levels,g round-and excitedstate dipole moments (m g and m e ), and the origin of electronic absorption spectra were studied by time-dependent DFT calculations. The second-order nonlinearo ptical (NLO) properties were determined by the electric-field-induced secondharmonic generation technique. The mb 1907 values of the bketoimines increased upon the formationo ft he related BF 2 complexes,m ainly due to an enhancement of the groundstate dipole moment. The resultsp resented here reveal that some of these novel compounds are excellent multifunctional candidates for NLO and luminescence applications.

Microstructure and electrical breakdown properties of blends and nanocomposites based on low-density polyethylene (LDPE) have been discussed. A series of LDPE nanocomposites containing different amount of organomodified montmorillonite (clay) with and without compatibilizer have been prepared by means of melt compounding. Two sets of blends of LDPE with two grades of Styrene-Ethylene-Butylene-Styrene block copolymers have been prepared to form cocontinuous structure and host the nanoreinforcement. A high degree of dispersion of oriented clay was observed through X-ray diffraction, scanning, and transmission electron microscopy. This was confirmed by the solid-like behavior of storage modulus in low frequencies in rheological measurement results. An alteration in the morphology of blends was witnessed upon addition of clay where the transportation phenomenon to the copolymer phase resulted in a downsizing on the domain size of the constituents of the immiscible blends. The AC breakdown strength of nanocomposites significantly increased when clay was incorporated. The partially exfoliated and intercalated clay platelets are believed to distribute the electric stress and prolong the breakdown time by creating a tortuous path for charge carriers. However, the incorporation of clay has been shown to diminish the DC breakdown strength of nanocomposites, mostly due to the thermal instability brought by clay.

Composites of low-density polyethylene (LDPE), ethylene vinyl acetate (EVA), and a graphene-like material were explored for their electrical properties for use in high-volume lowcost conductive applications. A graphene-like material, obtained from hybrid clay-sucrose carbonization, was investigated as an alternative filler with advantages over conventional graphene technology. The electrical properties of the composites as synthesized by the solvent-casting technique were studied using broadband dielectric spectroscopy. The percolation threshold was identified for both as synthesized and annealed composite samples. Due to charge transport and electrode polarization, the sub-percolating composites exhibited low frequency dispersion particularly at elevated temperatures. Composites of LDPE/EVA/graphene-like above the percolation threshold exhibited a higher rheological storage modulus and thermal stability which indicates an alignment between the electrical, thermal and rheological properties.