Evaluation of Mono and Bimetallic Ferrocene-Based 1,2,3-Triazolyl Compounds as Burning Rate Catalysts for Solid Rocket Motor.

We reported mono and bimetallic ferrocene-based 1,2,3-triazolyl compounds as potential burning rate catalysts in their neutral and ionic forms. All complexes reported here were characterized using 1H and 13C NMR, elemental analysis, and Mössbauer spectroscopy, which was performed for neutral and oxide compounds. The complexes present quasireversible redox potentials with higher oxidative ability than ferrocene and catocene under the same conditions. The complexes were tested as catalysts on the thermal decomposition of ammonium perchlorate (AP) and examined by a differential scanning calorimetry technique to gain further knowledge about their catalytic behavior. Compound 1 causes a decrease of the high-temperature decomposition (HTD) of AP positively, decreasing the decomposition temperature of AP to 345 °C and consequently increasing the energy release to 1939 J·g-1. We took the residues from the pans after testing from the DSC to elucidate the underlying reaction pathways. We obtained the size of the nanostructures formed after thermal decomposition of AP determined by the TEM technique. The diameter and size distribution of iron oxide nanoparticles formed depend on the alkyl sidechain of the triazolium ring, which induces the formation of nanoparticles with a double diameter and size distribution compared to their neutral analogues, suggesting that the possible intermediate for the mechanism degradation of AP by ferrocene derivatives is nanoscale Fe2O3 or similar oxides.

Alkylated Benzodithienoquinolizinium Salts as Possible Non-Fullerene Organic N-Type Semiconductors: An Experimental and Theoretical Study.

Three photobicyclized benzodithienoquinolizinium tetrafluoroborates (BPDTQBF4) were prepared and evaluated by UV-Vis and fluorescence spectral, electrochemical analysis, and by theoretical calculations as possible organic n-type semiconductors. Evaluation and comparison of their LUMO levels, HOMO-LUMO energy gaps as monomeric and π-stacked dimers with those of other materials, suggest their potential as organic n-type semiconductors. Calculations of their relative charge carrier mobilities confirmed this potential for one derivative with a long (C-14) alkyl chain appended to the polycyclic planar π-system.

Heterobimetallic Catalysts for the Thermal Decomposition of Ammonium Perchlorate: Efficient Burning Rate Catalysts for Solid Rocket Motors and Missiles.

We show the synthesis and characterization of four heterobimetallic compounds derived from s-indacene of general formula [{(CO)3Mn}-s-Ic-{MCp*}]q with M = Fe, Co, Ni, and Ru; q = 0, 1+. The complexes reported here were characterized by 1H and 13C NMR, elemental analysis and FT-IR. Additionally, the X-ray crystal structure of [(CO)3Mn-s-Ic-FeCp*] (1) and Mössbauer spectra are reported. The heterobimetallic compounds exhibit higher quasireversible redox potentials compared with ferrocene and catocene under the same reaction conditions. The complexes were tested as catalysts on the thermal decomposition of ammonium perchlorate examined by a differential scanning calorimetry technique to study their catalytic behavior. Compound (1) causes a decrease of ammonium perchlorate's decomposition temperature to 315 °C, consequently increasing the heat release by 138 J·g-1. Conversely, [{(CO)3Mn}-s-Ic'-{CoCp*}] (2) presents a higher heat release (2462 J·g-1), comparable to catocene.

Data of interaction of supported ionic liquids phases onto copper nanoparticles: A density functional theory study.

This work contains data on the computational, structural, and electronic characterization of supported ionic liquids phases anchored to copper nanoparticles using Density Functional theory calculations. The data supplement the paper "Interaction of supported ionic liquids phases onto copper nanoparticles: A Density Functional Theory study" [1], based on the adsorption of ionic liquid onto a Cu nanoparticle is analyzed from a chemical and physical point of view. The chemical analysis is based on Atoms in Molecule theory (AIM) and allows us to differentiate the chemical binding nature between ionic liquid and copper nanoparticle. On the other hand, the energy decomposition analysis based on absolutely localized molecular orbital (ALMO-EDA) describes the physical contributions that govern the interaction between ionic liquid and the copper nanoparticles. Herein, detailed and extended information in the synthesis and computational characterization are presented.

Highly modulated supported triazolium-based ionic liquids: direct control of the electronic environment on Cu nanoparticles.

A series of new triazolium-based supported ionic liquids (SILPs), decorated with Cu NPs, were successfully prepared and applied to the N-arylation of aryl halides with anilines. The triazoles moieties were functionalised using copper-catalysed azide-alkyne cycloaddition. SILP surface characterisation showed a strong correlation between the triazolium cation volume and textural properties. STEM images showed well-dispersed Cu NPs on SILPs with a mean diameter varying from 3.6 to 4.6 nm depending on the triazolium cation used. Besides, XPS results suggest that the Cu(0)/Cu(i) ratio can be modulated by the electronic density of triazolium substituents. XPS and computational analysis gave mechanistic insights into the Cu NP stabilisation pathways, where the presence of electron-rich groups attached to a triazolium ring plays a critical role in leading to a cation adsorption pathway (E ads = 72 kcal mol-1). In contrast, less electron-rich groups favour the anion adsorption pathway (E ads = 63 kcal mol-1). The Cu@SILP composite with electron-rich groups showed the highest activity for the C-N Ullmann coupling reaction, which suggests that electron-rich groups might act as an electron-like reservoir to facilitate oxidative addition for N-arylation. This strategy firmly suggests the strong dependence of the nature of triazolium-based SILPs on the Cu NP surface active sites, which may provide a new environment to confine and stabilise MNPs for catalytic applications.

Correction: Highly modulated supported triazolium-based ionic liquids: direct control of the electronic environment on Cu nanoparticles.

[This corrects the article DOI: 10.1039/D0NA00055H.].

Caracterización del uso de la plataforma MOODLE por estudiantes de ciencias de la salud / Characterization of the use of the MOODLE platform by the health sciences students

Fundamento: la tecnología diversifica la labor didáctica en los procesos pedagógicos mediados por las tecnologías de la información y las comunicaciones. Objetivo: caracterizar el uso de la plataforma MOODLE por alumnos de ciencias de la salud de la Universidad SEK de Santiago de Chile. Métodos: se realizó un estudio descriptivo transversal durante el año académico 2013. La población de estudio estuvo constituida por 1 328 estudiantes del área de la salud, y la muestra fue de 185 estudiantes seleccionados mediante un muestreo no probabilístico intencionado. Se utilizaron métodos teóricos: análisis-síntesis e inductivo-deductivo; y empíricos: revisión documental y encuesta (cuestionario) a los estudiantes. Resultados: la revisión de correo electrónico y la participación en redes sociales fueron los usos más frecuentes de internet en los estudiantes de ambos sexos. No existen diferencias significativas según el sexo en relación al uso de MOODLE. Ninguno de los sujetos informó participar en foros. Los formatos más utilizados en MOODLE son Power point, texto y videos. Según el nivel socioeconómico, solo existe diferencia en las acciones: descargar información y ver noticias. Conclusiones: el estudio realizado permitió constatar que es bajo el porcentaje de estudiantes que utilizan internet para la búsqueda de información, por lo que los autores consideran necesario incentivar a alumnos y docentes en el uso de los mecanismos de MOODLE para la interacción docente-alumno y alumno-alumno en aras de la calidad del proceso docente.

Background: technology diversifies the work of the pedagogical processes dominated by the communications and information technologies. Objective: to characterize the use of the MOODLE platform by the health sciences students in Santiago de Chile SEK University. Methods: a cross-sectional descriptive study was carried out in the academic year 2013. The study population comprised 1328 students of the health area and 185 students were included in a non-random purposive sampling. Theoretical methods were used: analysis-synthesis and induction-deduction. Empirical methods: review of documents and a survey was applied to the students. Results: the checking of e-mails and the participation in the social networks were the most frequent uses of internet by the students of both sexes. There are no meaningful differences about sex in relation to the use of MOODLE. None of them participated in forum. The most used formats of MOODLE were PowerPoint, texts, and videos. There are differences in the actions discharging information and viewing videos according to socio-economic standards. Conclusions: the study carried out allowed stating that a low percentage of students used internet to search information, so the author considers that it is necessary to incentivize teachers and students to use MOODLE for the teacher-student and student-student interaction so as to improve the quality of the teaching process.

Caracterización del uso de la plataforma MOODLE por estudiantes de ciencias de la salud / Characterization of the use of the MOODLE platform by the health sciences students

Fundamento: la tecnología diversifica la labor didáctica en los procesos pedagógicos mediados por las tecnologías de la información y la comunicación (TIC). Objetivo: caracterizar el uso de la plataforma MOODLE por alumnos de ciencias de la salud de la Universidad SEK de Santiago de Chile. Métodos: se realizó un estudio descriptivo transversal durante el año académico 2013. La población de estudio estuvo constituida por 1 328 estudiantes del área de la salud, y la muestra fue de 185 estudiantes seleccionados mediante un muestreo no probabilístico intencionado. Se utilizaron métodos teóricos: análisis-síntesis e inductivo-deductivo; y empíricos: revisión documental y encuesta (cuestionario) a los estudiantes. Resultados: la revisión de correo electrónico y la participación en redes sociales fueron los usos más frecuentes de internet en los estudiantes de ambos sexos. No existen diferencias significativas según el sexo en relación al uso de MOODLE. Ninguno de los sujetos informó participar en foros. Los formatos más utilizados en MOODLE son Power point, texto y videos. Según el nivel socioeconómico, solo existe diferencia en las acciones: descargar información y ver noticias. Conclusiones: el estudio realizado permitió constatar que es bajo el porcentaje de estudiantes que utilizan internet para la búsqueda de información, por lo que los autores consideran necesario incentivar a alumnos y docentes en el uso de los mecanismos de MOODLE para la interacción docente-alumno y alumno-alumno en aras de la calidad del proceso docente(AU)