22 research outputs found
Radiation Characteristics of a 0.11 Micrometer Modified Commercial CMOS Process
We present radiation data, Total Ionizing Dose and Single Event Effects, on the LSI Logic 0.11 micron commercial process and two modified versions of this process. Modified versions include a buried layer to guarantee Single Event Latchup immunity
Revisión de la historia y aplicación de escuaramida en organocatálisis
Squaramide and its derivatives represent an important group of substances that are currently being successfully applied in asymmetric organocatalitic strategies, which is why this contribution presents a summary of the state of the art related to the synthesis of escuaramide derivatives and their role as chirality inducers in relevant synthetic sequences. To this end, a process of systematic search and selection of reports published in specialized journals of the area was established in order to present the most significant aspects of synthesis and the application of escuaramide derivatives in this key area of organic chemistry.La escuaramida y sus derivados representan un importante grupo de sustancias que actualmente se están aplicando exitosamente en estrategias de organocatálisis asimétrica. En esta contribución se presenta un resumen del estado del arte relativo a la síntesis de los derivados de escuaramida y su papel como inductores de quiralidad en secuencias sintéticas relevantes. Por ello, se establece un proceso de búsqueda sistemática y selección de reportes publicados en revistas especializadas del área, con la finalidad de presentar los aspectos más notables de síntesis y la aplicación de los derivados de escuaramida en esta sustancial área de la química orgánica
Review of the history and application of squaramide in organocatalysis
Squaramide and its derivatives represent an important group of substances that are currently being successfully applied in asymmetric organocatalitic strategies, which is why this contribution presents a summary of the state of the art related to the synthesis of escuaramide derivatives and their role as chirality inducers in relevant synthetic sequences. To this end, a process of systematic search and selection of reports published in specialized journals of the area was established in order to present the most significant aspects of synthesis and the application of escuaramide derivatives in this key area of organic chemistry
Plasmonic Sensing of Aqueous-Divalent Metal Ions by Biogenic Gold Nanoparticles
The chemical interaction between biogenic gold nanoparticles (AuNPs) and several metal (II) ions can be regarded as a practical, twofold, colorimetric, and plasmon resonance sensing method for the recognition of some divalent metal ions in aqueous solutions. The green synthesized AuNPs, using Camellia sinensis as a reducing agent, were characterized by a surface plasmon resonance (SPR) using UV-Vis spectroscopy, infrared spectroscopy, and transmission electron microscopy. The AuNP colloidal solutions obtained have a pink-reddish color with SPRs centered between 529 and 536 nm. AuNPs with spherical, triangular, and hexagonal shapes were found by TEM analyses. Despite their divergent morphologies, these AuNPs can be employed as colorimetric and plasmon resonance sensors for detection of Ca2+, Sr2+, Cu2+, and Zn2+, primarily, in aqueous solutions. Sensibility studies based on molar concentrations were also performed for these metal ions. Furthermore, solid biogenic AuNPs/cellulosic biocomposites were prepared with the aim of developing portable, fast, and dependable colorimetric sensors; nevertheless, these biocomposites resulted to be good adsorbent materials of metal ions
Revisión de la historia y aplicación de escuaramida en organocatálisis
Squaramide and its derivatives represent an important group of substances that are currently being successfully applied in asymmetric organocatalitic strategies, which is why this contribution presents a summary of the state of the art related to the synthesis of escuaramide derivatives and their role as chirality inducers in relevant synthetic sequences. To this end, a process of systematic search and selection of reports published in specialized journals of the area was established in order to present the most significant aspects of synthesis and the application of escuaramide derivatives in this key area of organic chemistry.La escuaramida y sus derivados representan un importante grupo de sustancias que actualmente se están aplicando exitosamente en estrategias de organocatálisis asimétrica. En esta contribución se presenta un resumen del estado del arte relativo a la síntesis de los derivados de escuaramida y su papel como inductores de quiralidad en secuencias sintéticas relevantes. Por ello, se establece un proceso de búsqueda sistemática y selección de reportes publicados en revistas especializadas del área, con la finalidad de presentar los aspectos más notables de síntesis y la aplicación de los derivados de escuaramida en esta sustancial área de la química orgánica
Synthesis, Crystal Structures, and Molecular Properties of Three Nitro-Substituted Chalcones
Three functionalized chalcones containing combinations of nitro functional groups have been synthesized via Claisen-Schmidt condensation between 2-nitroacetophenone and nitrobenzaldehyde, and the crystal structures obtained ((E)-1,3-bis(2-nitrophenyl)prop-2-en-1-one, 1a, (E)-1-(2-nitrophenyl)-3-(3-nitrophenyl)prop-2-en-1-one, 1b and (E)-1-(2-nitrophenyl)-3-(4-nitrophenyl)prop-2-en-1-one, 1c), C15H10N2O5, are reported. Compounds 1a and 1c crystallized in the triclinic centrosymmetric space group P1¯, whereas compound 1b crystallized in the orthorhombic space group Pbca. The X-ray analysis reveals that structures 1a and 1b exhibits s-trans conformation, whereas structure 1c exists in s-cis conformation, concerning the olefinic double bonds. In addition, the results show that the position of the nitro substituent attached to the aromatic B-ring has a direct effect on the molecular coplanarity of these compounds. The Hirshfeld surface analysis suggests that the non-covalent π-π stacking interactions are the most important contributors for the crystal packing of 1a and 1b. In 1c, the crystal packing is mainly stabilized by weak intermolecular C―H···O interactions due to the planar nature of the molecule