Experimental and Theoretical Investigations of the Fragmentation of Ethylenediamine Induced by Low-Energy (<10 eV) Electrons

Ethylenediamine is industrially used as an intermediate for the fabrication of many products. The development of new methodologies for synthesis compatible with the environment and sustainability, such as cold plasma processes, implicates reactions induced by nonthermal electrons. In this contribution, we study the interaction of low-energy (<10 eV) electrons with ethylenediamine. We show that electrons induce the fragmentation of the molecule into various anion fragments and associated neutral counterparts via dissociative electron attachment. The fragmentation mechanisms and energetics are discussed in the frame of DFT calculations. The fragmentation processes are quantified by the estimation of the cross sections and the branching ratios for competitive accessible dissociation routes.

Renewable Schiff-Base Ionic Liquids for Lignocellulosic Biomass Pretreatment

Growing interest in sustainable sources of chemicals and energy from renewable and reliable sources has stimulated the design and synthesis of renewable Schiff-base (iminium) ionic liquids (ILs) to replace fossil-derived ILs. In this study, we report on the synthesis of three unique iminium-acetate ILs from lignin-derived aldehyde for a sustainable “future” lignocellulosic biorefinery. The synthesized ILs contained only imines or imines along with amines in their structure; the ILs with only imines group exhibited better pretreatment efficacy, achieving >89% sugar release. Various analytical and computational tools were employed to understand the pretreatment efficacy of these ILs. This is the first study to demonstrate the ease of synthesis of these renewable ILs, and therefore, opens the door for a new class of “Schiff-base ILs” for further investigation that could also be designed to be task specific.

Amino-modified Graphene Oxide/Fe3O4 for Dispersive Solid-Phase Extraction of Cadmium Ions in Rice, Lentil, and Water Samples

In this study, amino groups were directly coated on reduced graphene oxide sheets and applied for the extraction of cadmium(II) ions from well water, aqueduct (water coming from mountain), lentils and rice prior to measurements by flame atomic absorption spectrometry. The properties of the adsorbent were investigated by field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, Fourier-transform infrared spectroscopy and a vibrating sample magnetometer. Some parameters related to the adsorption and desorption stages were optimized. After preconcentration, the linear determination range of cadmium(II) was 0.5 - 40 μg L^-1. The limit of quantification, relative standard deviation and preconcentration factor were obtained as 0.5 μg L^-1, 0.39 - 2.18% and 100, respectively.

FeNxC Based Catalysts Prepared by the Calcination of Iron-Ethylenediamine@Polyaniline as the Cathode-Catalyst of Proton Exchange Membrane Fuel Cell

Calcinated tris(ethylenediamine)iron(III) chloride was used as a non-precious metal catalyst (NPMCs) for a proton exchanged membrane fuel cell (PEMFC) under the protection of polyaniline (PANI), which behaves as both nitrogen source and carbon supporter. The optimal ratio of FeCl3/EDA was found to be close to 1/3 under the consideration of the electrocatalytic performance, such as better oxygen reduction reaction (ORR) and higher power density. Two-stage calcination, one at 900 °C in N2 and the other at 800 °C in mixed gases of N2 and NH3, result in an FeNxC catalyst (FeNC-900-800-A) with pretty high specific surface area of 1098 m2·g-1 covered with both micro- and mesopores. The ORR active sites focused mainly on Fe-Nx bonding made of various pyridinic, pyrrolic, and graphitic N-s after calcination. The max. power density reaches 140 mW·cm-2 for FeNC-900-800-A, which is superior to other FeNxC catalysts, experiencing only one-stage calcination in N2. The FeNxC demonstrates only 10 mV half-wave-voltage (HWV) loss at 1600 rpm after 1000 redox cycles, as compared to be 27 mV for commercial Pt/C catalyst in the durability test.

Syntheses and PDT activity of new mono- and di-conjugated derivatives of chlorin e6

Syntheses of three new chlorin e₆ conjugates for PDT of tumors are reported. One of the new compounds 17 is conjugated with lysine at the 13¹-position, but the others are mono-conjugated 14 or diconjugated 15 with the non-amino acid species ethanolamine. Cellular experiments with the three new compounds and previously synthesized non-amino acid 15²-conjugates (7-10), 13¹-monoconjugates 14, 16, and a 13¹,15²-diconjugate 12 are reported. In vitro cytotoxicity experiments show that the 13¹-conjugates are more toxic than the 15²-conjugates, and the most toxic derivative (dark- and photo-toxicity) is the 13¹-ethylenediamine conjugate 11. The most useful PDT photosentitizers appear to be the ethanolamine derivatives, conjugated at the 15²- and the 13¹,15²-positions; these show high phototoxicity but relatively low dark toxicity compared with 11, and also the highest dark/photo cytotoxicity ratios.