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Hong He - One of the best experts on this subject based on the ideXlab platform.
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poly bis dimethyl formamide μ7 5 5 methyl enedi oxy diisophthalato dizinc dimethyl formamide monosolvate
Acta Crystallographica Section E-structure Reports Online, 2011Co-Authors: Chuan-qiang Li, Hong HeAbstract:In the crystal structure of the title coordination polymer, {[Zn2(C17H8O10)(C3H7NO)2]·C3H7NO}n, the molecular building block (MBB), viz. {Zn2(CO2)4(C3H7NO)2}, comprises two zinc atoms, each bridged by three carboxylate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal–pyramidal, and square–pyramidal formed by the two coordinated dimethylformamide molecules and three Carboxylate groups, and a distorted tetrahedral coordination defined by carboxylate groups of which three are bidentate bridging and the fourth is a monodentate ligand. Thus, each ligand connects four MBBs, forming the three-dimensional polymer.
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Poly[[bis(dimethylformamide)[μ7-5,5′-(methylenedioxy)diisophthalato]dizinc] dimethylformamide monosolvate]
Acta Crystallographica Section E-structure Reports Online, 2011Co-Authors: Chuan-qiang Li, Hong HeAbstract:In the crystal structure of the title coordination polymer, {[Zn2(C17H8O10)(C3H7NO)2]·C3H7NO}n, the molecular building block (MBB), viz. {Zn2(CO2)4(C3H7NO)2}, comprises two zinc atoms, each bridged by three carboxylate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal–pyramidal, and square–pyramidal formed by the two coordinated dimethylformamide molecules and three Carboxylate groups, and a distorted tetrahedral coordination defined by carboxylate groups of which three are bidentate bridging and the fourth is a monodentate ligand. Thus, each ligand connects four MBBs, forming the three-dimensional polymer.
Ewa Bryszewska - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver Carboxylate precursors
Journal of Nanoparticle Research, 2017Co-Authors: Pawel Uznanski, Joanna Zakrzewska, Frédéric Favier, Slawomir Kazmierski, Ewa BryszewskaAbstract:A comparative study of amine and silver Carboxylate adducts [R1COOAg-2(R2NH2)] (R1 = 1, 7, 11; R2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (1H and 13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver Carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver Carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal Carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver Carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-Carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting Carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.
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Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver Carboxylate precursors
Journal of Nanoparticle Research, 2017Co-Authors: Pawel Uznanski, Joanna Zakrzewska, Frédéric Favier, Slawomir Kazmierski, Ewa BryszewskaAbstract:A comparative study of amine and silver Carboxylate adducts [R_1COOAg-2(R_2NH_2)] (R_1 = 1, 7, 11; R_2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, ^13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (^1H and ^13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver Carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver Carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal Carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver Carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-Carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting Carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism. Graphical abstract The synthesis of a series (bis)alkylamine silver(I) Carboxylate complexes in nonpolar solvents were carried out and fully characterized both in the solid and solution. Carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination. The complexes form layered structures which thermally decompose forming nanoparticles stabilized only by aliphatic Carboxylates.
Chuan-qiang Li - One of the best experts on this subject based on the ideXlab platform.
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poly bis dimethyl formamide μ7 5 5 methyl enedi oxy diisophthalato dizinc dimethyl formamide monosolvate
Acta Crystallographica Section E-structure Reports Online, 2011Co-Authors: Chuan-qiang Li, Hong HeAbstract:In the crystal structure of the title coordination polymer, {[Zn2(C17H8O10)(C3H7NO)2]·C3H7NO}n, the molecular building block (MBB), viz. {Zn2(CO2)4(C3H7NO)2}, comprises two zinc atoms, each bridged by three carboxylate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal–pyramidal, and square–pyramidal formed by the two coordinated dimethylformamide molecules and three Carboxylate groups, and a distorted tetrahedral coordination defined by carboxylate groups of which three are bidentate bridging and the fourth is a monodentate ligand. Thus, each ligand connects four MBBs, forming the three-dimensional polymer.
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Poly[[bis(dimethylformamide)[μ7-5,5′-(methylenedioxy)diisophthalato]dizinc] dimethylformamide monosolvate]
Acta Crystallographica Section E-structure Reports Online, 2011Co-Authors: Chuan-qiang Li, Hong HeAbstract:In the crystal structure of the title coordination polymer, {[Zn2(C17H8O10)(C3H7NO)2]·C3H7NO}n, the molecular building block (MBB), viz. {Zn2(CO2)4(C3H7NO)2}, comprises two zinc atoms, each bridged by three carboxylate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal–pyramidal, and square–pyramidal formed by the two coordinated dimethylformamide molecules and three Carboxylate groups, and a distorted tetrahedral coordination defined by carboxylate groups of which three are bidentate bridging and the fourth is a monodentate ligand. Thus, each ligand connects four MBBs, forming the three-dimensional polymer.
Jim-min Fang - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of polycyclic and 4,5-diacylthiophene-2-Carboxylates via intramolecular Friedel–Crafts alkylations and unusual autooxidative fragmentation of the derivatives obtained from the samarium diiodide-promoted coupling reactions of thiophene-2-car
Tetrahedron, 2007Co-Authors: Shyh-ming Yang, Jim-min FangAbstract:Abstract Our present study provides an expedient method for the synthesis of novel polycyclic and multi-substituted thiophene derivatives. A series of 4,5-di(hydroxyalkyl)-4,5-dihydrothiophene-2-Carboxylates (e.g., 4a–c and 10) were prepared by the SmI2-promoted three-component coupling reactions of thiophene-2-Carboxylate with aromatic aldehydes and 4-methoxyacetophenone. Diol 4a was oxidized by DDQ or pyridinium dichromate to give 5-acyl-4-hydroxyalkyl-4,5-dihydrothiophene-2-Carboxylate 6a, which was subjected to dehydration to give either alkene 7 with terminal C C double bond or alkene 15a having conjugation with the ester group, depending on the reaction conditions using different quantities of p-toluenesulfonic acid. Alkene 7 underwent an intramolecular Friedel–Crafts alkylation to give a tetralone-fused thiophene-2-Carboxylate 9. By the similar procedure, a carbazole-fused thiophene 14 was also prepared. Alkenes 15a–c underwent autooxidative fragmentation to give 4,5-diacylthiophene-2-Carboxylates 5a–c that were elaborated to pyridazine-fused thiophenes.
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synthesis of polycyclic and 4 5 diacylthiophene 2 Carboxylates via intramolecular friedel crafts alkylations and unusual autooxidative fragmentation of the derivatives obtained from the samarium diiodide promoted coupling reactions of thiophene 2 car
Tetrahedron, 2007Co-Authors: Shyh-ming Yang, Jim-min FangAbstract:Abstract Our present study provides an expedient method for the synthesis of novel polycyclic and multi-substituted thiophene derivatives. A series of 4,5-di(hydroxyalkyl)-4,5-dihydrothiophene-2-Carboxylates (e.g., 4a – c and 10 ) were prepared by the SmI 2 -promoted three-component coupling reactions of thiophene-2-Carboxylate with aromatic aldehydes and 4-methoxyacetophenone. Diol 4a was oxidized by DDQ or pyridinium dichromate to give 5-acyl-4-hydroxyalkyl-4,5-dihydrothiophene-2-Carboxylate 6a , which was subjected to dehydration to give either alkene 7 with terminal C C double bond or alkene 15a having conjugation with the ester group, depending on the reaction conditions using different quantities of p -toluenesulfonic acid. Alkene 7 underwent an intramolecular Friedel–Crafts alkylation to give a tetralone-fused thiophene-2-Carboxylate 9 . By the similar procedure, a carbazole-fused thiophene 14 was also prepared. Alkenes 15a – c underwent autooxidative fragmentation to give 4,5-diacylthiophene-2-Carboxylates 5a – c that were elaborated to pyridazine-fused thiophenes.
Pawel Uznanski - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver Carboxylate precursors
Journal of Nanoparticle Research, 2017Co-Authors: Pawel Uznanski, Joanna Zakrzewska, Frédéric Favier, Slawomir Kazmierski, Ewa BryszewskaAbstract:A comparative study of amine and silver Carboxylate adducts [R1COOAg-2(R2NH2)] (R1 = 1, 7, 11; R2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (1H and 13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver Carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver Carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal Carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver Carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-Carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting Carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.
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Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver Carboxylate precursors
Journal of Nanoparticle Research, 2017Co-Authors: Pawel Uznanski, Joanna Zakrzewska, Frédéric Favier, Slawomir Kazmierski, Ewa BryszewskaAbstract:A comparative study of amine and silver Carboxylate adducts [R_1COOAg-2(R_2NH_2)] (R_1 = 1, 7, 11; R_2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, ^13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (^1H and ^13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver Carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver Carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal Carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver Carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-Carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting Carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism. Graphical abstract The synthesis of a series (bis)alkylamine silver(I) Carboxylate complexes in nonpolar solvents were carried out and fully characterized both in the solid and solution. Carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination. The complexes form layered structures which thermally decompose forming nanoparticles stabilized only by aliphatic Carboxylates.