2018 |
Pinto, C; Galdámez, A; Barahona, P; Moris, S; Pena, O Crystal Structure, Raman Scattering and Magnetic Properties of Cucr2-Xzrxse4 and Cucr2-Xsnxse4 Selenospinels Artículo de revista Journal of Magnetism and Magnetic Materials, 456 , pp. 160-166, 2018, ISSN: 0304-8853. Resumen | Enlaces | BibTeX | Etiquetas: colossal crystal geometry magnetic magnetoresistance, properties, raman selenospinel, spectroscopy, structure @article{RN401, title = {Crystal Structure, Raman Scattering and Magnetic Properties of Cucr2-Xzrxse4 and Cucr2-Xsnxse4 Selenospinels}, author = { C. Pinto and A. Gald\'{a}mez and P. Barahona and S. Moris and O. Pena}, url = {/brokenurl#<Go to ISI>://WOS:000427580800023}, doi = {10.1016/j.jmmm.2018.02.023}, issn = {0304-8853}, year = {2018}, date = {2018-01-01}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {456}, pages = {160-166}, publisher = {2018 Elsevier B.V.}, abstract = {Selenospinels, CuCr2-xMxSe4 (M = Zr and Sn), were synthesized via conventional solid-state reactions. The crystal structure of CuCr1.5Sn0.5Se4, CuCr1.7Sn0.3Se4, CuCr1.5Zr0.5Se4, and CuCr1.8Zr0.2Se4 were determined using single-crystal X-ray diffraction. All the phases crystallized in a cubic spinel-type structure. The chemical compositions of the single-crystals were examined using energy-dispersive X-ray analysis (EDS). Powder X-ray diffraction patterns of CuCr1.3Sn0.7Se4 and CuCr1.7Sn0.3Se4 were consistent with phases belonging to the Fd3m Space group. An analysis of the vibrational properties on the single-crystals was performed using Raman scattering measurements. The magnetic properties showed a spin glass behavior with increasing Sn content and ferromagnetic order for CuCr1.7Sn0.3Se4.}, keywords = {colossal crystal geometry magnetic magnetoresistance, properties, raman selenospinel, spectroscopy, structure}, pubstate = {published}, tppubtype = {article} } Selenospinels, CuCr2-xMxSe4 (M = Zr and Sn), were synthesized via conventional solid-state reactions. The crystal structure of CuCr1.5Sn0.5Se4, CuCr1.7Sn0.3Se4, CuCr1.5Zr0.5Se4, and CuCr1.8Zr0.2Se4 were determined using single-crystal X-ray diffraction. All the phases crystallized in a cubic spinel-type structure. The chemical compositions of the single-crystals were examined using energy-dispersive X-ray analysis (EDS). Powder X-ray diffraction patterns of CuCr1.3Sn0.7Se4 and CuCr1.7Sn0.3Se4 were consistent with phases belonging to the Fd3m Space group. An analysis of the vibrational properties on the single-crystals was performed using Raman scattering measurements. The magnetic properties showed a spin glass behavior with increasing Sn content and ferromagnetic order for CuCr1.7Sn0.3Se4. |
Cassels, B K; Saez-Briones, P Dark Classics in Chemical Neuroscience: Mescaline Artículo de revista Acs Chemical Neuroscience, 9 (10), pp. 2448-2458, 2018, ISSN: 1948-7193. Resumen | Enlaces | BibTeX | Etiquetas: analogs, biosynthesis, cancer, derivatives, diethylamide, hallucinogen, hallucinogenic life-threatening lysergic-acid mescaline, metabolism, pedro, peyote, pharmacology, phenethylamine, phenyl-aethylamine, properties, relationships, san serotonin stimulus structure-activity synthesis, wachuma @article{RN389, title = {Dark Classics in Chemical Neuroscience: Mescaline}, author = { B.K. Cassels and P. Saez-Briones}, url = {/brokenurl#<Go to ISI>://WOS:000447954300015}, doi = {10.1021/acschemneuro.8b00215}, issn = {1948-7193}, year = {2018}, date = {2018-01-01}, journal = {Acs Chemical Neuroscience}, volume = {9}, number = {10}, pages = {2448-2458}, abstract = {Archeological studies in the United States, Mexico, and Peru suggest that mescaline, as a cactus constituent, has been used for more than 6000 years. Although it is a widespread cactus alkaloid, it is present in high concentrations in few species, notably the North American peyote (Lophophora williamsii) and the South American wachuma (Trichocereus pachanoi, T. peruvianus, and T. bridgesii). Spanish 16th century chroniclers considered these cacti "diabolic", leading to their prohibition, but their use persisted to our days and has been spreading for the last 150 years. In the late 1800s, peyote attracted scientific attention; mescaline was isolated, and its role in the psychedelic effects of peyote tops or "mescal buttons" was demonstrated. Its structure was established by synthesis in 1929, and alternative routes were developed, providing larger amounts for pharmacological and biosynthetic research. Although its effects are attributed mainly to its action as a 5-HT2A serotonin receptor agonist, mescaline binds in a similar concentration range to 5-HT1A and alpha(2A) receptors. It is largely excreted unchanged in human urine, and its metabolic products are apparently unrelated to its psychedelic properties. Its low potency is probably responsible for its relative neglect by recreational substance users, as the successful search for structure-activity relationships in the hallucinogen field focused largely on finding more potent analogues. Renewed interest in the possible therapeutic applications of psychedelic drugs may hopefully lead to novel insights regarding the commonalities and differences between the actions of individual classic hallucinogens.}, keywords = {analogs, biosynthesis, cancer, derivatives, diethylamide, hallucinogen, hallucinogenic life-threatening lysergic-acid mescaline, metabolism, pedro, peyote, pharmacology, phenethylamine, phenyl-aethylamine, properties, relationships, san serotonin stimulus structure-activity synthesis, wachuma}, pubstate = {published}, tppubtype = {article} } Archeological studies in the United States, Mexico, and Peru suggest that mescaline, as a cactus constituent, has been used for more than 6000 years. Although it is a widespread cactus alkaloid, it is present in high concentrations in few species, notably the North American peyote (Lophophora williamsii) and the South American wachuma (Trichocereus pachanoi, T. peruvianus, and T. bridgesii). Spanish 16th century chroniclers considered these cacti "diabolic", leading to their prohibition, but their use persisted to our days and has been spreading for the last 150 years. In the late 1800s, peyote attracted scientific attention; mescaline was isolated, and its role in the psychedelic effects of peyote tops or "mescal buttons" was demonstrated. Its structure was established by synthesis in 1929, and alternative routes were developed, providing larger amounts for pharmacological and biosynthetic research. Although its effects are attributed mainly to its action as a 5-HT2A serotonin receptor agonist, mescaline binds in a similar concentration range to 5-HT1A and alpha(2A) receptors. It is largely excreted unchanged in human urine, and its metabolic products are apparently unrelated to its psychedelic properties. Its low potency is probably responsible for its relative neglect by recreational substance users, as the successful search for structure-activity relationships in the hallucinogen field focused largely on finding more potent analogues. Renewed interest in the possible therapeutic applications of psychedelic drugs may hopefully lead to novel insights regarding the commonalities and differences between the actions of individual classic hallucinogens. |
2017 |
Martinez-Cifuentes, M; Salazar, R; Ramirez-Rodriguez, O; Weiss-Lopez, B; Araya-Maturana, R Experimental and Theoretical Reduction Potentials of Some Biologically Active Ortho-Carbonyl Para-Quinones Artículo de revista Molecules, 22 (4), 2017, ISSN: 1420-3049. Resumen | Enlaces | BibTeX | Etiquetas: aprotic-solvents, aqueous-solution, batteries botrytis-cinerea, computational cyclic density density-functional electrochemistry, electron-transfer, functional ion models, p-benzoquinone, potential, properties, quinones, redox semiquinone, solvation theory, voltammetry @article{RN372, title = {Experimental and Theoretical Reduction Potentials of Some Biologically Active Ortho-Carbonyl Para-Quinones}, author = { M. Martinez-Cifuentes and R. Salazar and O. Ramirez-Rodriguez and B. Weiss-Lopez and R. Araya-Maturana}, url = {/brokenurl#<Go to ISI>://WOS:000404517800075}, doi = {10.3390/molecules22040577}, issn = {1420-3049}, year = {2017}, date = {2017-01-01}, journal = {Molecules}, volume = {22}, number = {4}, abstract = {The rational design of quinones with specific redox properties is an issue of great interest because of their applications in pharmaceutical and material sciences. In this work, the electrochemical behavior of a series of four p-quinones was studied experimentally and theoretically. The first and second one-electron reduction potentials of the quinones were determined using cyclic voltammetry and correlated with those calculated by density functional theory (DFT) using three different functionals, BHandHLYP, M06-2x and PBE0. The differences among the experimental reduction potentials were explained in terms of structural effects on the stabilities of the formed species. DFT calculations accurately reproduced the first one-electron experimental reduction potentials with R-2 higher than 0.94. The BHandHLYP functional presented the best fit to the experimental values (R-2 = 0.957), followed by M06-2x (R-2 = 0.947) and PBE0 (R-2 = 0.942).}, keywords = {aprotic-solvents, aqueous-solution, batteries botrytis-cinerea, computational cyclic density density-functional electrochemistry, electron-transfer, functional ion models, p-benzoquinone, potential, properties, quinones, redox semiquinone, solvation theory, voltammetry}, pubstate = {published}, tppubtype = {article} } The rational design of quinones with specific redox properties is an issue of great interest because of their applications in pharmaceutical and material sciences. In this work, the electrochemical behavior of a series of four p-quinones was studied experimentally and theoretically. The first and second one-electron reduction potentials of the quinones were determined using cyclic voltammetry and correlated with those calculated by density functional theory (DFT) using three different functionals, BHandHLYP, M06-2x and PBE0. The differences among the experimental reduction potentials were explained in terms of structural effects on the stabilities of the formed species. DFT calculations accurately reproduced the first one-electron experimental reduction potentials with R-2 higher than 0.94. The BHandHLYP functional presented the best fit to the experimental values (R-2 = 0.957), followed by M06-2x (R-2 = 0.947) and PBE0 (R-2 = 0.942). |
2015 |
Diaz, C; Barrera, G; Segovia, M; Valenzuela, M L; Osiak, M; O'dwyer, C Crystallizing Vanadium Pentoxide Nanostructures in the Solid-State Using Modified Block Copolymer and Chitosan Complexes Artículo de revista Journal of Nanomaterials, 10.1155/2015/105157 , 2015, ISSN: 1687-4110. Resumen | Enlaces | BibTeX | Etiquetas: electrochemical gold growth, intercalation, mechanisms, nanocomposites, nanoparticles, optical-properties, photoluminescence, precursors, properties, ruthenium @article{RN255, title = {Crystallizing Vanadium Pentoxide Nanostructures in the Solid-State Using Modified Block Copolymer and Chitosan Complexes}, author = { C. Diaz and G. Barrera and M. Segovia and M.L. Valenzuela and M. Osiak and C. O'dwyer}, url = {/brokenurl#<Go to ISI>://WOS:000354681800001}, doi = {10.1155/2015/105157}, issn = {1687-4110}, year = {2015}, date = {2015-01-01}, journal = {Journal of Nanomaterials}, volume = {10.1155/2015/105157}, abstract = {A systematic study of the synthesis of V2O5 nanostructured materials using macromolecular PS-co-4-PVP center dot(VCl3)(y) and chitosan center dot(VCl3)(y) complexes is presented. It is demonstrated that various coordination degrees of the metal into the polymeric chain specifically influence the product formation after pyrolysis. PS-co-4-PVP center dot(VCl3)(y) and chitosan center dot(VCl3)(y) complexes were prepared by simple coordination reaction of VCl3 with the respective polymer inmolar ratios 1 : 1, 1 : 5, and 1 : 10 metal/polymer and characterized by elemental analysis, IR spectroscopy, and TGA/DSC analysis. Solid-state thermolysis of these precursors at several temperatures under air results in nanostructured V2O5 using all precursors. The size and shape of the nanostructured V2O5 depend on the nature of the polymer. For the chitosan center dot(VCl3)(y) precursors sub-10nm nanocrystals are formed. The calcination process, involved in the preparation method, produces V2O5 with photoluminescence in the visible light region, suggesting the possible application in oxygen sensing devices.}, keywords = {electrochemical gold growth, intercalation, mechanisms, nanocomposites, nanoparticles, optical-properties, photoluminescence, precursors, properties, ruthenium}, pubstate = {published}, tppubtype = {article} } A systematic study of the synthesis of V2O5 nanostructured materials using macromolecular PS-co-4-PVP center dot(VCl3)(y) and chitosan center dot(VCl3)(y) complexes is presented. It is demonstrated that various coordination degrees of the metal into the polymeric chain specifically influence the product formation after pyrolysis. PS-co-4-PVP center dot(VCl3)(y) and chitosan center dot(VCl3)(y) complexes were prepared by simple coordination reaction of VCl3 with the respective polymer inmolar ratios 1 : 1, 1 : 5, and 1 : 10 metal/polymer and characterized by elemental analysis, IR spectroscopy, and TGA/DSC analysis. Solid-state thermolysis of these precursors at several temperatures under air results in nanostructured V2O5 using all precursors. The size and shape of the nanostructured V2O5 depend on the nature of the polymer. For the chitosan center dot(VCl3)(y) precursors sub-10nm nanocrystals are formed. The calcination process, involved in the preparation method, produces V2O5 with photoluminescence in the visible light region, suggesting the possible application in oxygen sensing devices. |
2014 |
Barahona, P; Galdámez, A; Lopez-Vergara, F; Manriquez, V; Pena, O Crystal Structure and Magnetic Properties of Titanium-Based Cuti2-Xmxs4 and Cucr2-Xtixse4 Chalcospinels Artículo de revista Journal of Solid State Chemistry, 212 , pp. 114-120, 2014, ISSN: 0022-4596. Resumen | Enlaces | BibTeX | Etiquetas: chalcospinel, copper crystal cucr2se4, cuti2s4, electrical-properties, geometry, lithium, magnetic polyhedra, properties, spinel structure, thiospinels, transport-properties @article{RN203, title = {Crystal Structure and Magnetic Properties of Titanium-Based Cuti2-Xmxs4 and Cucr2-Xtixse4 Chalcospinels}, author = { P. Barahona and A. Gald\'{a}mez and F. Lopez-Vergara and V. Manriquez and O. Pena}, url = {/brokenurl#<Go to ISI>://WOS:000333071400017}, doi = {10.1016/j.jssc.2014.01.017}, issn = {0022-4596}, year = {2014}, date = {2014-01-01}, journal = {Journal of Solid State Chemistry}, volume = {212}, pages = {114-120}, publisher = {2014 Elsevier Inc.}, abstract = {CuTi2-xMxS4 (M=Fe, Mn, Co; x=0.3, 0.5) and CuCr2-xTixSe4 (x=03, 0.5, 0.7) chalcospinels were synthesized by conventional solid-state reactions. Their crystal structures were determined by single-crystal X-ray diffraction. All of the phases crystallized in cubic spinel-type structures (space group, Fd (3) over barm). For all of the chalcospinel compounds, the edge-length distortion parameter (ELD) indicated that the most distorted polyhedron was Q[(Ti,M)(3)Cu], which displayed an similar to 8% distortion from an ideal tetrahedron structure (Q=S or Se)., The Mn-based thiospinel CuMn0.3Ti1.7S4 is paramagnetic, whereas the Fe-based thiospinels (CuTi2-xFexS4; x=0.3 and 0.7) are strongly antiferromagnetic due to their spin-glass states. The magnetic susceptibility measurements indicated ferromagnetic behavior for the selenospinels (CuCr2-xTixSe4; x=0.3, 0.5 and 0.7).}, keywords = {chalcospinel, copper crystal cucr2se4, cuti2s4, electrical-properties, geometry, lithium, magnetic polyhedra, properties, spinel structure, thiospinels, transport-properties}, pubstate = {published}, tppubtype = {article} } CuTi2-xMxS4 (M=Fe, Mn, Co; x=0.3, 0.5) and CuCr2-xTixSe4 (x=03, 0.5, 0.7) chalcospinels were synthesized by conventional solid-state reactions. Their crystal structures were determined by single-crystal X-ray diffraction. All of the phases crystallized in cubic spinel-type structures (space group, Fd (3) over barm). For all of the chalcospinel compounds, the edge-length distortion parameter (ELD) indicated that the most distorted polyhedron was Q[(Ti,M)(3)Cu], which displayed an similar to 8% distortion from an ideal tetrahedron structure (Q=S or Se)., The Mn-based thiospinel CuMn0.3Ti1.7S4 is paramagnetic, whereas the Fe-based thiospinels (CuTi2-xFexS4; x=0.3 and 0.7) are strongly antiferromagnetic due to their spin-glass states. The magnetic susceptibility measurements indicated ferromagnetic behavior for the selenospinels (CuCr2-xTixSe4; x=0.3, 0.5 and 0.7). |
Sieveking, I; Thomas, P; Estevez, J C; Quinones, N; Cuellar, M A; Villena, J; Espinosa-Bustos, C; Fierro, A; Tapia, R A; Maya, J D; Lopez-Munoz, R; Cassels, B K; Estevez, R J; Salas, C O 2-Phenylaminonaphthoquinones and Related Compounds: Synthesis, Trypanocidal and Cytotoxic Activities Artículo de revista Bioorganic & Medicinal Chemistry, 22 (17), pp. 4609-4620, 2014, ISSN: 0968-0896. Resumen | Enlaces | BibTeX | Etiquetas: activity, antimalarial antineoplastic assay, benzocarbazolequinones, biological colorimetric cruzi, cytotoxicity, derivatives, electronic evaluation, general-route, properties, quinones, t. trypanosoma-cruzi @article{RN190, title = {2-Phenylaminonaphthoquinones and Related Compounds: Synthesis, Trypanocidal and Cytotoxic Activities}, author = { I. Sieveking and P. Thomas and J.C. Estevez and N. Quinones and M.A. Cuellar and J. Villena and C. Espinosa-Bustos and A. Fierro and R.A. Tapia and J.D. Maya and R. Lopez-Munoz and B.K. Cassels and R.J. Estevez and C.O. Salas}, url = {/brokenurl#<Go to ISI>://WOS:000341293300010}, doi = {10.1016/j.bmc.2014.07.030}, issn = {0968-0896}, year = {2014}, date = {2014-01-01}, journal = {Bioorganic & Medicinal Chemistry}, volume = {22}, number = {17}, pages = {4609-4620}, publisher = {2014 Elsevier Ltd.}, abstract = {A series of new 2-aminonaphthoquinones and related compounds were synthesized and evaluated in vitro as trypanocidal and cytotoxic agents. Some tested compounds inhibited epimastigote growth and trypomastigote viability. Several compounds showed similar or higher activity and selectivity as compared with current trypanocidal drug, nifurtimox. Compound 4l exhibit higher selectivity than nifurtimox against Trypanosoma cruzi in comparison with Vero cells. Some of the synthesized quinones were tested against cancer cells and normal fibroblasts, showing that certain chemical modifications on the naphthoquinone moiety induce and excellent increase the selectivity index of the cytotoxicity (4g and 10). The results presented here show that the anti-T. cruzi activity of 2-aminonaphthoquinones derivatives can be improved by the replacement of the benzene ring by a pyridine moiety. Interestingly, the presence of a chlorine atom at C-3 and a highly lipophilic alkyl group or aromatic ring are newly observed elements that should lead to the discovery of more selective cytotoxic and trypanocidal compounds.}, keywords = {activity, antimalarial antineoplastic assay, benzocarbazolequinones, biological colorimetric cruzi, cytotoxicity, derivatives, electronic evaluation, general-route, properties, quinones, t. trypanosoma-cruzi}, pubstate = {published}, tppubtype = {article} } A series of new 2-aminonaphthoquinones and related compounds were synthesized and evaluated in vitro as trypanocidal and cytotoxic agents. Some tested compounds inhibited epimastigote growth and trypomastigote viability. Several compounds showed similar or higher activity and selectivity as compared with current trypanocidal drug, nifurtimox. Compound 4l exhibit higher selectivity than nifurtimox against Trypanosoma cruzi in comparison with Vero cells. Some of the synthesized quinones were tested against cancer cells and normal fibroblasts, showing that certain chemical modifications on the naphthoquinone moiety induce and excellent increase the selectivity index of the cytotoxicity (4g and 10). The results presented here show that the anti-T. cruzi activity of 2-aminonaphthoquinones derivatives can be improved by the replacement of the benzene ring by a pyridine moiety. Interestingly, the presence of a chlorine atom at C-3 and a highly lipophilic alkyl group or aromatic ring are newly observed elements that should lead to the discovery of more selective cytotoxic and trypanocidal compounds. |
2013 |
Diaz, C; Valenzuela, M L; Caceres, S; Diaz, R; O'dwyer, C Solvent and Stabilizer Free Growth of Ag and Pd Nanoparticles Using Metallic Salts/Cyclotriphosphazenes Mixtures Artículo de revista Materials Chemistry and Physics, 143 (1), pp. 124-132, 2013, ISSN: 0254-0584. Resumen | Enlaces | BibTeX | Etiquetas: annealing, derivatives, electron gold, mechanical-behavior, metals, microscopy, nanoparticles, nanorods organometallic palladium polyphosphazenes, precursors, properties, pyrolysis, shape-controlled solid-state surface synthesis, thermolytic transformation @article{RN146, title = {Solvent and Stabilizer Free Growth of Ag and Pd Nanoparticles Using Metallic Salts/Cyclotriphosphazenes Mixtures}, author = { C. Diaz and M.L. Valenzuela and S. Caceres and R. Diaz and C. O'dwyer}, url = {/brokenurl#<Go to ISI>://WOS:000327684100017}, doi = {10.1016/j.matchemphys.2013.08.034}, issn = {0254-0584}, year = {2013}, date = {2013-01-01}, journal = {Materials Chemistry and Physics}, volume = {143}, number = {1}, pages = {124-132}, publisher = {2013 Elsevier B.V.}, abstract = {Cyclotriphosphazene is used as a sacrificial solid-state template to synthesize a range of Ag and Pd nanoparticles with diverse geometries by thermal treatment using MLn/N3P3(O2C12H8)(3) mixtures. The Pd and Ag nanoparticles are synthesized by solid-state pyrolysis of AgPPh3[CF3SO3]/N3P3(O2C12H8)(3) and PdCl2/N3P3(O2C12H8)(3) mixtures with molar relationships of 1:1, 1:5 and 1:10 respectively, in air and at 800 degrees C. The morphology of the as-prepared nanoparticles is found to depend on the molar ratio of the precursor mixture, the preparation method and of the nature of the metal. Ag and Pd, microcrystals were thermally grown on Si from the respective 1:1 precursors while that metal foams were grown from 1:5 ratios precursors on SiO2 wafers. High resolution transmission electron microscopy investigations reveal in most cases small crystals of Pd. HRSTEM measurements indicate that the formation of the Pd and Ag nanoparticles occurs through a phase demixing and dewetting mechanism. This approach has potential to be a useful and facile method to prepare metallic nanoparticles without requiring solutions or surfactants for application in electronic, catalytic and sensor materials and devices.}, keywords = {annealing, derivatives, electron gold, mechanical-behavior, metals, microscopy, nanoparticles, nanorods organometallic palladium polyphosphazenes, precursors, properties, pyrolysis, shape-controlled solid-state surface synthesis, thermolytic transformation}, pubstate = {published}, tppubtype = {article} } Cyclotriphosphazene is used as a sacrificial solid-state template to synthesize a range of Ag and Pd nanoparticles with diverse geometries by thermal treatment using MLn/N3P3(O2C12H8)(3) mixtures. The Pd and Ag nanoparticles are synthesized by solid-state pyrolysis of AgPPh3[CF3SO3]/N3P3(O2C12H8)(3) and PdCl2/N3P3(O2C12H8)(3) mixtures with molar relationships of 1:1, 1:5 and 1:10 respectively, in air and at 800 degrees C. The morphology of the as-prepared nanoparticles is found to depend on the molar ratio of the precursor mixture, the preparation method and of the nature of the metal. Ag and Pd, microcrystals were thermally grown on Si from the respective 1:1 precursors while that metal foams were grown from 1:5 ratios precursors on SiO2 wafers. High resolution transmission electron microscopy investigations reveal in most cases small crystals of Pd. HRSTEM measurements indicate that the formation of the Pd and Ag nanoparticles occurs through a phase demixing and dewetting mechanism. This approach has potential to be a useful and facile method to prepare metallic nanoparticles without requiring solutions or surfactants for application in electronic, catalytic and sensor materials and devices. |
2011 |
Diaz, C; Valenzuela, M L; Yutronic, N; Villalobos, V; Barrera, G Nanostructured Vox/Vo(Po4)(N) Using Solid-State Vanadium Containing Phosphazene Precursors: A Useful Potential Bi-Catalyst System Artículo de revista Journal of Cluster Science, 22 (4), pp. 693-704, 2011, ISSN: 1040-7278. Resumen | Enlaces | BibTeX | Etiquetas: autogenic cyclophosphazenes, derivatives, electrochemical elevated-temperature, gold, morphology, nanofibres nanoparticles, organometallic polyphosphazenes, pressure, properties, pyrolysis, template, vanadium @article{RN32i, title = {Nanostructured Vox/Vo(Po4)(N) Using Solid-State Vanadium Containing Phosphazene Precursors: A Useful Potential Bi-Catalyst System}, author = { C. Diaz and M.L. Valenzuela and N. Yutronic and V. Villalobos and G. Barrera}, url = {/brokenurl#<Go to ISI>://WOS:000297250000012}, doi = {10.1007/s10876-011-0415-1}, issn = {1040-7278}, year = {2011}, date = {2011-01-01}, journal = {Journal of Cluster Science}, volume = {22}, number = {4}, pages = {693-704}, abstract = {Pyrolysis of molecular precursors containing vanadium organometallic and cyclic phosphazene affords mixtures of nanostructured vanadium oxides and pyrophosphates. The products from the molecular precursor [N3P3(OC6H5)(5)OC5H4N center dot Cp2VCl][PF6], and of the mixtures Cp2VCl2/N3P3(OC6H4CHO)(6) and Cp2VCl2/[NP(O2C12H8)](3) in several relationships 1:1, 1:3, 1:5 and 1:10, pyrolyzed under air and at 400 A degrees C and 600 A degrees C, give mixtures mainly V2O5 and VO(PO3)(2). Varied morphologies depending on the molecular or mixture precursors and of the temperature used were observed. Nanowires with diameters of approximate 40 nm were observed for the 1:5 Cp2VCl2/[NP(O2C12H8)](3) mixture pyrolyzed at 400 A degrees C, while the same mixture pyrolyzed at 600 A degrees C, affords xerogels of V2O5. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), infra-red (IR) spectroscopy and X-ray diffraction (XRD). The preparation method constitutes a novel one-pot solid-state way to nanostructured materials with potential applications both in oxidative dehydrogenation of light hydrocarbons with V2O5, as well as alkenes oxidations with VO(PO3)(2).}, keywords = {autogenic cyclophosphazenes, derivatives, electrochemical elevated-temperature, gold, morphology, nanofibres nanoparticles, organometallic polyphosphazenes, pressure, properties, pyrolysis, template, vanadium}, pubstate = {published}, tppubtype = {article} } Pyrolysis of molecular precursors containing vanadium organometallic and cyclic phosphazene affords mixtures of nanostructured vanadium oxides and pyrophosphates. The products from the molecular precursor [N3P3(OC6H5)(5)OC5H4N center dot Cp2VCl][PF6], and of the mixtures Cp2VCl2/N3P3(OC6H4CHO)(6) and Cp2VCl2/[NP(O2C12H8)](3) in several relationships 1:1, 1:3, 1:5 and 1:10, pyrolyzed under air and at 400 A degrees C and 600 A degrees C, give mixtures mainly V2O5 and VO(PO3)(2). Varied morphologies depending on the molecular or mixture precursors and of the temperature used were observed. Nanowires with diameters of approximate 40 nm were observed for the 1:5 Cp2VCl2/[NP(O2C12H8)](3) mixture pyrolyzed at 400 A degrees C, while the same mixture pyrolyzed at 600 A degrees C, affords xerogels of V2O5. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), infra-red (IR) spectroscopy and X-ray diffraction (XRD). The preparation method constitutes a novel one-pot solid-state way to nanostructured materials with potential applications both in oxidative dehydrogenation of light hydrocarbons with V2O5, as well as alkenes oxidations with VO(PO3)(2). |
Publicaciones 2011-2020
