- Synthesis and characterization of one, two and three-dimensional Cu(I) polymers supported by bipyridylamide ligands
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Reaction of bipyridylamide ligands N-(3-pyridyl)nicotinamide (3-pna), N-(4-pyridyl)nicotinamide (4-pna) and N-(4-pyridyl)isonicotinamide (4-pina) with Cu(I) salts afforded four coordination polymers. X-ray crystallography analysis showed one-, two- and three-dimensional networks. The correlation between the pyridyl nitrogen donor disposition and dimensionality of the structures was discussed. Reflectance UV–Vis and fluorescence spectroscopic methods were used to characterize the MLCT features of these complexes. Thermal stability of the coordination polymers under nitrogen was also investigated.
- Mugenzi, Clement,Powell, Douglas R.,Gerasimchuk, Nikolay N.,Yang, Lei
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- Proton magnetic resonance study of the molecular conformation of N-(3-pyridinyl)3-pyridinecarboxamide, N-(3-pyridinyl)acetamide and 3-pyridinecarboxamide
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The 1H NMR spectra of N-(3-pyridinyl) 3-pyridinecarboxamide, N-(3-pyridinyl)acetamide and 3-pyridinecarboxamide in different solvents have been assigned utilizing the COSY spectra, chemical shift and coupling constant correlations. The 1H NMR spectra, NOE experiments and MINDO/3 calculations have been utilized for obtaining information on the molecular conformation. The results suggest that in dilute solutions, the 3-pyridyl rings are not coplanar with the amide group, which is in trans orientation in all the three compounds.
- Singha, Nethai C.,Anand, Jayashree,Sathyanarayana
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- Nickel adipate coordination polymers with isomeric dipyridylamide ligands: Topological disorder and divergent magnetic properties
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Hydrothermal reaction of nickel nitrate, adipic acid, and a dipyridylamide ligand produced two coordination polymers which were structurally characterized by single-crystal X-ray diffraction. {[Ni2(adipate)2(3-pna)2(H2O)]·H2O}n (1, 3-pna = 3-pyridylnicotinamide) possesses carboxylate bridged {Ni(μ2-H2O)(OCO)2} dimeric units connected into (6,3) graphitic 2D layer motifs. Use of the isomeric 3-pyridylisonicotinamide (3-pina) afforded {[Ni2(adipate)2(3-pina)2(H2O)]·2H2O}n (2), which manifested similar {Ni(μ2-H2O)(OCO)2} dimeric units. Crystallographic disorder within the adipate ligands in 2 produced a 3D coordination polymer net that is a hybrid of a non-interpenetrated 3D 6-connected primitive cubic α-Po 41263pcu net and 2D 7-connected slab motifs with a pillared (3,6) triangular net 3641253 topology. Magnetic analysis for 1 revealed weak antiferromagnetic coupling (J = -0.36(1) cm-1 with g = 2.077(1)), while 2 exhibited weak ferromagnetic coupling (J = +0.51(2) cm-1 with g = 2.034(7)).
- White, Charmaine L.,La Duca, Robert L.
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- Hydrogen-bonded 3D network of d10-metal halide coordination polymer containing N-(3-pyridinyl) nicotinamide: influence of ligand conformation, halide anions and solvent
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In this study, four new d10-metal halide coordination polymers (CPs), namely [HgCl2 (3-pna)]n (1), [HgBr2(3-pna)]n (2), [HgI2(3-pna)]n CH3OH (3) and [CdI2(3-pna)]n (4), (3-pna = N-(3-pyridinyl)nicotinamide) were prepared through the reaction of mercury(ii) or cadmium(ii) salts with 3-pna by a solution-based method and structurally characterized via single-crystal X-ray diffraction. Moreover, X-ray crystal structure determination of 3-pna is reported for the first time. From the viewpoint of green chemistry, solid state reactivity of the starting materials of compounds 1 and 2 was investigated by mechanochemical and thermal synthesis methods under solvent-free conditions. Powder X-ray diffraction (PXRD) patterns of the reaction mixture upon grinding of the starting reactant and powders isolated from heating the reactant materials were successfully matched with simulated PXRD patterns of the compounds. According to single-crystal X-ray analysis, all compounds 1-4 are isostructural CPs as one-dimensional (1D) zigzag chains based on the anti conformation of the ligand. The accompanying halogen ions are observed to form C/N-HX (X = Cl, Br, I) hydrogen bonds resulting in 3D supramolecular architectures. The presence of solvent molecules in the mercury iodide complex expands the packing structure with the change of halogen-based interactions to N-HOsolvent and C-HOamide interactions. Conformational dependence of ligand interactions was investigated on the reported 3-pna complexes in the Cambridge Structural Database (CSD). The results revealed that supramolecular synthons of the amide skeleton of the ligand as well as the polymeric architecture of the complex are significantly influenced by the anti/syn conformation of the ligand.
- Nezhadali Baghan, Zahra,Salimi, Alireza,Eshtiagh-Hosseini, Hossein,Oliver, Allen G.
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- Luminescent cadmium 1,3-adamantanedicarboxylate coordination polymers with diverse topologies depending on dipyridylamide ligands
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Hydrothermal reaction of cadmium nitrate, 1,3-adamantanedicarboxylic acid (adcH2), and a hydrogen-bonding capable dipyridylamide ligand afforded five crystalline coordination polymers whose dimensionality depends on the dipyridylamide length and nitrogen donor disposition. The five new phases were structurally characterized via single-crystal X-ray diffraction. [Cd(adc)(4-pmina)]n(1, 4-pmina?=?4-pyridylmethylisonicotinamide) displays a (4,4) grid topology with [Cd(adc)]nchains pillared by the dipodal dipyridylamide ligands. {[Cd(adc)(4-pmna)(H2O)]·4H2O}n(2, 4-pmna?=?4-pyridylmethylnicotinamide) displays a similar layered topology, but with octameric water molecule clusters residing in the interlamellar regions. {[Cd(adc)(3-pna)(H2O)]·6H2O}n(3, 3-pna?=?3-pyridylnicotinamide) possesses 1-D ribbon submotifs due to the syn-conformation and shorter tether length of the dipyridylamide ligands. Compound 3 entrains intriguing “infinite” water molecule tapes comprised of 4- and 5-membered rings. {[Cd2(adc)2(3-pina)2]·H2O}n(4, 3-pina?=?3-pyridylisonicotinamide) manifests a 4-connected 3D 658?cds topology. The minor coordination polymer chain product {[Cd(adc)(3-pyram)2(H2O)]·2H2O}n(5) was isolated along with 4 (3-pyram?=?3-pyridylamine). Luminescent behavior in 1–4 is attributed to intra-ligand molecular orbital transitions. The new phases were also surveyed for the ability to detect nitrobenzene in ethanol suspension. Thermal decomposition behavior is also discussed herein.
- LaRose, Cassi J.,LaDuca, Robert L.
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- Dipyridylamide ligand dependent dimensionality in luminescent zinc 2,4-pyridinedicarboxylate coordination complexes
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Zinc nitrate, 2,4-pyridinedicarboxylic acid (2,4-pdcH2), and a hydrogen-bonding capable dipyridylamide ligand were combined in aqueous solution and subjected to hydrothermal reaction conditions. Three new crystalline coordination complexes were generated; their dimensionality depends crucially on the dipyridylamide length and geometric disposition of the pyridyl nitrogen donors. The three new phases were structurally characterized via single-crystal X-ray diffraction. {[H23-pina][Zn(2,4-pdc)2(H2O)2]·H2O} (1, 3-pina = 3-pyridylisonicotinamide) is a salt with protonated dipyridylamide cations and coordination complex anions. {[Zn2(2,4-pdc)2(H2O)4(3-pna)]·3H2O}n (2, 3-pna = 3-pyridylnicotinamide) shows a system of two-fold interpenetrated ruffled (6,3) coordination polymer layers. {[Zn(2,4-pdc)(H2O)2(3-pmna)]n (3, 3-pmna = 3-pyridylmethylnicotinamide) manifests a simple 1D chain topology. Luminescence was observed for two of the zinc complexes; this behavior is attributed to π-π?or π-n molecular orbital transitions. Thermal decomposition properties of the new phases are also probed.
- Wudkewych, Megan J.,Laduca, Robert L.
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- Metal ion control of dimensionality and self-penetration in coordination polymers containing furandicarboxylate and dipyridylamide ligands
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Hydrothermal reaction of metal nitrates, 2,5-furandicarboxylic acid (H2fdc) and the conformationally flexible dipyridylamide ligand 3-pyridylnicotinamide (3-pna) afforded three new coordination polymers which were structurally characterized by single-crystal X-ray diffraction. {[Cd2(fdc)2(3-pna)(H2O)4]·6H2O}n(1) exhibits a 1D ladder structural motif with tethering anti-conformation 3-pna ligands acting as the rungs. {[Ni(fdc)(3-pna)2(H2O)]·2.5H2O}n(2) displays a (4,4) rhomboid grid structure that resembles a rarer (3,6) triangular grid if supramolecular interactions provided by pendant syn-conformation 3-pna ligands are considered. [Co(fdc)(3-pna)(H2O)]n(3) manifests {Co2(OCO)2} anti-syn dimer-based 3-connected 4.82layers pillared into a novel 3D 3,5-connected self-penetrated (4.6.8)(4.658310) topology network by anti-conformation 3-pna ligands. The specific metal coordination environments, fdc binding mode, and 3-pna conformation act synergistically to enforce structure direction in this system. Thermal decomposition properties of these three new materials are also discussed.
- White, Charmaine L.,LaDuca, Robert L.
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- Zinc and Cadmium Diphenate Coordination Polymers with Conformationally Flexible Dipyridylamide Ligands
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Zinc and cadmium diphenate (dip, biphenyl-2,2′-dicarboxylate) coordination polymers containing conformationally flexible dipyridylamide ligands show diverse chain and layer topologies as determined by single-crystal X-ray diffraction. [Cd(dipH)2(bdin)]n (1) [bdin = N,N′-(butane-1,3-diyl)diisonicotinamide] shows a simple 1D zigzag chain structure. {[Cd(dip)(pdin)(H2O)]·1.25H2O}n (2) [pdin = N,N′-(propane-1,3-diyl)diisonicotinamide] shows bilayer slabs formed by interleaving of (4,4) rectangular grid layers. {[Zn2(dip)2(3-pna)2]·3H2O}n (3) (3-pna = 3-pyridylnicotinamide) manifests a rare 4-connected 1D ribbon topology. {[Cd(dip)(4-ppbp)]·2H2O}n (4) [4-ppbp = propane-1,3-diylbis(piperidine-4,1-diyl)bis(pyridin-4-ylmethanone)] shows a 3,5-connected layer with (426)(42678) 3,5L2 topology. {[Zn4(dip)4(H2O)2(4-ppbp)2]·12H2O}n (5) exhibits 2D 3,6-connected layers with (43)2(466683) kgd topology featuring embedded R(8)A(2) classification 10-membered water clusters. Compounds 1, 4, and 5 undergo violet or blue-violet fluorescence upon ultraviolet irradiation. Thermal decomposition behavior of the new phases is also discussed.
- Martinez, Brianna L.,LaDuca, Robert L.
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- N-(Pyridin-3-yl)benzamides as selective inhibitors of human aldosterone synthase (CYP11B2)
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A series of 23 N-(Pyridin-3-yl)benzamides was synthesized and evaluated for their potential to inhibit human steroid-11β-hydroxylase (CYP11B1) and human aldosterone synthase (CYP11B2). The most potent and selective CYP11B2 inhibitors (IC50 valu
- Zimmer, Christina,Hafner, Marieke,Zender, Michael,Ammann, Dominic,Hartmann, Rolf W.,Vock, Carsten A.
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supporting information; experimental part
p. 186 - 190
(2011/02/25)
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- Water-mediated catalyst preactivation: An efficient protocol for C-N cross-coupling reactions
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(Figure Presented) A protocol for forming a highly active Pd(O) catalyst from Pd(OAc)2, water, and biaryldialkylphosphine ligands has been developed. This protocol generates a catalyst system, which exhibits excellent reactivity and efficiency in the coupling of a variety of amides and anilines with aryl chlorides.
- Fors, Brett P.,Krattiger, Philipp,Strieter, Eric,Buchwald, Stephen L.
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supporting information; experimental part
p. 3505 - 3508
(2009/05/07)
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- Pd-catalyzed amidations of aryl chlorides using monodentate biaryl phosphine ligands: A kinetic, computational, and synthetic investigation
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We present results on the amidation of aryl halides and sulfonates utilizing a monodentate biaryl phosphine-Pd catalyst. Our results are in accord with a previous report that suggests that the formation of κ2- amidate complexes is deleterious to the effectiveness of a catalyst for this transformation and that their formation can be prevented by the use of appropriate bidentate ligands. We now provide data that suggest that the use of certain monodentate ligands can also prevent the formation of the κ2-amidate complexes and thereby generate more stable catalysts for the amination of aryl chlorides. Furthermore, computational studies shed light on the importance of the key feature(s) of the biaryl phosphines (a methyl group ortho to the phosphorus center) that enable the coupling to occur. The use of ligands that possess a methyl group ortho to the phosphorus center allows a variety of aryl and heteroaryl chlorides with various amides to be coupled in high yield.
- Ikawa, Takashi,Barder, Timothy E.,Biscoe, Mark R.,Buchwald, Stephen L.
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p. 13001 - 13007
(2008/09/17)
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- A Contrivance for a Dynamic Porous Framework: Cooperative Guest Adsorption Based on Square Grids Connected by Amide - Amide Hydrogen Bonds
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Flexible porous coordination polymers containing amide groups as a function origin have been synthesized and categorized as Coordination Polymer with Amide Groups . Bispyridyl ligands with a spacer of amide group afford two-dimensional (2-D) motifs with a deformed square grid, resulting in three-dimensional (3-D) frameworks of [Co(NO3) 2(3-pna)2]n (1), [Co(Br) 2(3-pna)2]n (2), and {[Co(NCS) 2(4-peia)2]· 4Me2CO}n (3 ? 4Me2CO) (3-pna = N-3-pyridylnicotinamide, 4-peia = N-(2-pyridin-4-yl-ethyl)-isonicotinamide), where the 2-D motifs are bound by complementary hydrogen bond between the amide groups. In the case of the 3 ? 4Me2CO, the amide groups form a contrivance for a dynamic porous framework because of their relevant position and orientation in the mutual nearest neighboring motifs. Consequently, 3 ? 4Me2CO shows amorphous (nonporous)-to-crystal (porous) structural rearrangement in the Me2CO adsorption and desorption process, where the framework of the 2-D motif is maintained. The adsorption isotherm has threshold pressure (P th), a sort of gate pressure. The heat of Me2CO adsorption (ΔHad = -25 kJ/mol) is obtained from the temperature dependence of threshold pressure (Pth), which is close to acetone vaporization enthalpy (ΔHvap = 30.99 kJ/mol).
- Uemura, Kazuhiro,Kitagawa, Susumu,Fukui, Koichi,Saito, Kazuya
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p. 3817 - 3828
(2007/10/03)
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- Design and synthesis of piperidine-3-carboxamides as human platelet aggregation inhibitors
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A detailed structure-activity analysis was carried out using eight 1- alkyl(aralkyl)nipecotamides (type 5), 33 bis-nipecotamidoalkanes and aralkanes (type 6), and 7 N,N'-bis(nipecotoyl)-piperazines (type 7) as inhibitors of human platelet aggregation. Steric factors played an important role in determining the activity of type 5 compounds possessing an appropriate degree of hydrophobic character. Types 6 and 7 compounds were more potent than the corresponding type 5 molecules. Hydrophobic character appeared to influence the activity of type 6 compounds. A 3-substituent on the piperidine ring was necessary for antiplatelet activity; the substituent should be preferably an amide with its C attached directly to the ring. 3,5- Disubstitution and 2-substitution led to a decline in activity. Optimal activity was attained when the two nipecotoyl ring N atoms were connected by an aralkyl group, and separated by ~7 ?. It is suggested that van der Waals forces and π interactions may govern the inhibitor-platelet interaction. The most potent type 6 inhibitor was α,α'-bis[3-(N-ethyl-N- butylcarbamoyl)piperidino]-p-xylene (6i). The most potent type 5 compound was 1-decyl-3-(N,N-diethylcarbamoyl)piperidine (5a). Any substitution on the piperazine ring of type 7 compounds led to a decline in activity, the most active analog being N,N'-bis(1-decylnipecotoyl)piperazine (7a). It is suggested that nipecotamides interact with anionic platelet sites located 7 ? from each other and connected by a hydrophobic well.
- Zheng,Salgia,Thompson,Dillingham,Bond,Feng,Prasad,Gollamudi
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p. 180 - 188
(2007/10/02)
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