Browsing by Autor "Pilar Delgado–Niño"

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CRYSTAL STRUCTURE OF THE QUATERNARY SEMICONDUCTOR COMPOUND CuFeCrSe3
(2019) Gerzón E. Delgado; Pilar Delgado–Niño; P. Grima
The compounds with ternary structures of the chalcopyrite family Cu-III-Se2 (III = Al, Ga, In, Cr) form a wide group of semiconductor materials with diverse optical and electrical properties, and the addition of FeSe binary compound produces alloys of the type (Cu-III-Se2)1-x(Fe-Se)x. These types of materials have received increasing attention as promising thermoelectric materials due to their high efficiency, tunable transport properties, high elemental abundance and low toxicity. This work aims to synthesize and characterize structurally a new material belonging to this semiconductor system with x = ½, the quaternary compound CuFeCrSe3. This material was prepared by the melt and anneal technique and its structure was refined from Xray powder diffraction pattern using the Rietveld method. The X-ray powder pattern was mainly composed of CuFeCrSe3 (79.1%) with CuCr2Se4 (20.9%) appearing as secondary phase. The principal phase crystallizes with tetragonal symmetry in the space group P 4 2c (Nº 112), Z = 1, with a = 5.5082(2) Å, c = 10.943(1) Å, V = 332.01(1) Å3. The refinement of 18 instrumental and structural parameters led to Rp = 8.8 %, Rwp = 9.1 %, Rexp = 7.8 % and S = 1.2. This material, belonging to the semiconductor system I-II-III-VI3, crystallizes with a CuFeInSe3-type structure in a normal adamantane-structure. CuFeCrSe3 is a new semiconductor compound, related to the superionic phase CuCrSe2, and can be considered as a potential candidate for mediumtemperature thermoelectric applications.
Synthesis, differential thermal analysis, and crystal structure of the quaternary chalcogenide compound Cu2FeGeTe4
(Mexican Society of Physics, 2026) Gerzón E. Delgado; Eugenio Quintero; Pilar Delgado–Niño; Rosmary Guillen-Guillen; Gerson Márquez
This study reports on the quaternary diamond-like semiconductor copper iron germanium tellurium, Cu2FeGeTe4. The material was synthesized using the melt and annealing technique by directly reacting the elements. The thermal behavior of the Cu2FeGeTe4 compound was investigated using thermogravimetric analysis. The Rietveld refinement method characterized the crystal structure through X-ray powder diffraction. The powder diffraction pattern revealed that the principal phase, Cu2FeGeTe4, constituted 85.4%, while the secondary phase, FeTe2, accounted for 14.6%. The quaternary chalcogenide compound Cu2FeGeTe4 belongs to the I2-II-IV-VI4 system and crystallizes in the stannite structure within the non-centrosymmetric tetragonal space group I-42m (Nº 121), Z= 2, with unit cell parameters a= 5.9293(8) Å, c= 11.9239(8) Å, V= 419.20(2) Å3. Its structure consists of a three-dimensional close-packed arrangement of slightly distorted CuTe4, FeTe4, and GeTe4 tetrahedra, interconnected through shared faces and corners. The chemical structure was verified through Bond Valence Sum (BVS) calculations
X-RAY POWDER DIFFRACTION DATA FOR A NEW PIRAZOLINE COMPOUND
(2019) Gerzón E. Delgado; Pilar Delgado–Niño; Robert Lobatón; S-M LIEW; Joazaizulfazli Jamalis
Pyrazolines are important agents in medicinal chemistry as a promising scaffold for structural modification and drug development studies due to their wide range of biological activities such as anticancer, antifungal, antibacterial, antidepressant, anticonvulsant, antitubercular, antioxidant, antileishmanial and antiinflammatory activity. These heterocyclic compounds can be prepared by refluxing chalcone with hydrazine hydrate and anhydrous sodium acetate in the presence of glacial acetic acid. The structural characterization, molecular and crystalline structure, of these organic compounds, allows studying their biological properties to know their potential applications. Hence the use of XRPD is very important because it allows obtaining a record to be used as a method of identification. The aim of this investigation was to obtain and reported good quality Xray powder diffraction data the pyrazoline compound 1-(3-(4-iodophenyl)-5-(3-methyl thiophen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl)ethan-1-one, which could be used as potential anti-microbial and anti-cancer agent. The powder pattern was indexed in the monoclinic space group I2/a with unit cell parameters a = 25.440(5) Å, b = 5.124(2) Å, c = 26.261(6) Å, b = 105.75(2)° and figures of merit M20= 38.2 and F20= 66.6 (0.00573, 53). All measured lines were indexed and are consistent with the monoclinic space group. The powder pattern will be included in the Powder Diffraction File database to be used as a reference.
X-RAY POWDER DIFFRACTION DATA FOR A NEW THIOPHENE CHALCONE OBTAINED BY A CLAISEN-SCHMIDT REACTION
(2019) Gerzón E. Delgado; Pilar Delgado–Niño; Joazaizulfazli Jamalis
Chalcones and their heterocyclic derivatives have gained considerable importance in recent years due to their wide range of pharmacological properties including anti-AIDS agents, anti-bacterial, anti-malarial, antiinflammatory, anti-leishmanial, anti-oxidant, anti-cancer, anti-tuberculosis anti-microbial activity. These important compounds are conventionally synthesized by Claisen-Schmidt condensation reaction in which aldehyde reacted with acetophenone in the presence of aqueous alkaline bases. Hence the importance of characterizing new derivatives using different techniques both spectroscopic and diffractometric to know their molecular and crystalline structure, but also techniques that allow to study their biological properties to know their possible applications. X-ray powder diffraction is the technique most widely used for the identification of crystalline materials and hence the importance of reporting powder patterns in the Powder Diffraction File database. Therefore, the objective of this investigation is to obtain and reported good quality X-ray powder diffraction data (d-spacing and relative intensity of observed hkl reflections) of the new hetererocyclic chalcone derivative; (E)-3-(5-bromo thiophen-2-yl)-1-(2,5-dichlorothiophen-3-yl)-2-propen-1-one. This new compound was synthesized by Claisen-Schmidt condensation method among a series of thiophene derivative chalcones as potential anti-cancer and anti-microbial agents. The powder pattern was indexed in the monoclinic space group P21/n with unit cell parameters a= 4.0323(7) Å, b= 13.551(3) Å, c= 23.511(5) Å, β= 94.27(1), Z = 4, V= 1281.1(3) Å3, and figures of merit M20= 18.2 and F30= 47.6 (0.0143, 44). All measured lines were indexed and are consistent with the monoclinic space group.