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Synthesis And Crystal Structures Of 3,6-DiHyDroxyPicolinic Acid And Its Labile InterMediate Dipotassium 3-HyDrOxy-6-(SulfonatoOxy)Pyridine-2-CarboxylAte Monohydrate, Edward J. Behrman, Sean R. Parkin
Synthesis And Crystal Structures Of 3,6-DiHyDroxyPicolinic Acid And Its Labile InterMediate Dipotassium 3-HyDrOxy-6-(SulfonatoOxy)Pyridine-2-CarboxylAte Monohydrate, Edward J. Behrman, Sean R. Parkin
Chemistry Faculty Publications
A simplified two-step synthesis of 3,6-dihydroxypicolinic acid (3-hydroxy-6-oxo-1,6-dihydropyridine-2-carboxylic acid), C6H5NO4 (II), an intermediate in the metabolism of picolinic acid, is described. The crystal structure of II, along with that of a labile intermediate, dipotassium 3-hydroxy-6-(sulfonatooxy)pyridine-2-carboxylate monohydrate, 2K+·C6H3NO7S2−·H2O (I), is also described. Compound I comprises a pyridine ring with carboxylate, hydroxyl (connected by an intramolecular O—H⋯O hydrogen bond), and sulfate groups at the 2-, 3-, and 6-positions, respectively, along with two potassium cations for charge balance and one water …
Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman
Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman
Chemistry Faculty Publications
The structure of zymonic acid (systematic name: 4-hydroxy-2-methyl-5-oxo-2,5-dihydrofuran-2-carboxylic acid), C6H6O5, which had previously eluded crystallographic determination, is presented here for the first time. It forms by intramolecular condensation of parapyruvic acid, which is the product of aldol condensation of pyruvic acid. A redetermination of the crystal structure of pyruvic acid (systematic name: 2-oxopropanoic acid), C3H4O3, at low temperature (90 K) and with increased precision, is also presented [for the previous structure, see: Harata et al. (1977). Acta Cryst. B33, 210–212]. In zymonic acid, the hydroxylactone ring …
Crystal Structure Of The 13-(E)-(2-Aminobenzylidene)-Parthenolide, Shobanbabu Bommagani, Narsihma R. Penthala, Sean Parkin, Peter A. Crooks
Crystal Structure Of The 13-(E)-(2-Aminobenzylidene)-Parthenolide, Shobanbabu Bommagani, Narsihma R. Penthala, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C21H25NO3 [systematic name: (1aR,4E,7aS,8E,10aS,10bR)-8-(2-aminobenzylidene)-1a,5-dimethyl-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one], was synthesized by the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bS,E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] with 2-iodoaniline via Heck reaction conditions. The molecule is composed of fused ten-, five- (lactone), and three-membered (epoxide) rings. The lactone ring shows a flattened envelope-type conformation (r.m.s. deviation from planarity = 0.0477 Å), and bears a 2-aminobenzylidene substituent that is disordered over two conformations [occupancy …
Crystal Structure Of 4,4′-Bis[3-(Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-BiphenYl, Anqi Walbaum, E. Kim Fifer, Sean R. Parkin, Peter A. Crooks
Crystal Structure Of 4,4′-Bis[3-(Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-BiphenYl, Anqi Walbaum, E. Kim Fifer, Sean R. Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C28H32N2, (I), is one of a second generation of compounds designed and synthesized based on a very potent and selective α9α10 nicotinic acetylcholine receptor antagonist ZZ161C {1,1′-[[1,1′-biphenyl]-4,4′-diylbis(prop-2-yne-3,1-diyl)]bis(3,4-dimethylpyridin-1-ium) bromide}, which has shown analgesic effects in a chemotherapy-induced neuropathy animal model. Compound (I) was synthesized by the reaction of 4,4′-bis(3-bromoprop-1-yn-1-yl)-1,1′-biphenyl with piperidine at room temperature in acetonitrile. The single-crystal used for X-ray analysis was obtained by dissolving (I) in a mixture of dichloromethane and methanol, followed by slow evaporation of the solvent. In the crystal of (I), the biphenyl moiety has a twisted …
Crystal Structures Of (Z)-5-[2-(Benzo[B]Thiophen-2-Yl)-1-(3,5-Dimethoxyphenyl)Ethenyl]-1H-Tetrazole And (Z)-5-[2-(Benzo[B]Thiophen-3-Yl)-1-(3,4,5-Trimethoxyphenyl)Ethenyl]-1H-Tetrazole, Narsimha Reddy Penthala, Jaishankar K. B. Yadlapalli, Sean Parkin, Peter A. Crooks
Crystal Structures Of (Z)-5-[2-(Benzo[B]Thiophen-2-Yl)-1-(3,5-Dimethoxyphenyl)Ethenyl]-1H-Tetrazole And (Z)-5-[2-(Benzo[B]Thiophen-3-Yl)-1-(3,4,5-Trimethoxyphenyl)Ethenyl]-1H-Tetrazole, Narsimha Reddy Penthala, Jaishankar K. B. Yadlapalli, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
(Z)-5-[2-(Benzo[b]thiophen-2-yl)-1-(3,5-dimethoxyphenyl)ethenyl]-1H-tetrazole methanol monosolvate, C19H16N4O2S·CH3OH, (I), was prepared by the reaction of (Z)-3-(benzo[b]thiophen-2-yl)-2-(3,5-dimethoxyphenyl)acrylonitrile with tributyltin azide via a [3 + 2]cycloaddition azide condensation reaction. The structurally related compound (Z)-5-[2-(benzo[b]thiophen-3-yl)-1-(3,4,5-trimethoxyphenyl)ethenyl]-1H-tetrazole, C20H18N4O3S, (II), was prepared by the reaction of (Z)-3-(benzo[b]thiophen-3-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with tributyltin azide. Crystals of (I) have two molecules in the asymmetric unit (Z′ = 2), whereas crystals of (II) have Z′ …
Crystal Structure Of (E)-13-(Pyrimidin-5-Yl)Parthenolide, Shobanbabu Bommagani, Narsimha Reddy Penthala, Sean Parkin, Peter A. Crooks
Crystal Structure Of (E)-13-(Pyrimidin-5-Yl)Parthenolide, Shobanbabu Bommagani, Narsimha Reddy Penthala, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C19H22N2O3, {systematic name (1aR,4E,7aS,8E,10aS,10bR)-1a,5-dimethyl-8-[(pyrimidin-5-yl)methylidene]-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one} was obtained from the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bR,E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] with 5-bromopyrimidine under Heck reaction conditions, and was identified as an E isomer. The molecule possesses ten-, five- (lactone) and three-membered (epoxide) rings with a pyrimidine group as a substituent. The ten-membered ring displays an approximate chair–chair conformation, while the lactone ring shows a flattened …
Comparison Of The Crystal Structures Of 4,4′-Bis[3-(4-MethylPiperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-BiPhenyl And 4,4′-Bis[3-(2,2,6,6-TetraMethylPiperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-BiphenYl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks
Comparison Of The Crystal Structures Of 4,4′-Bis[3-(4-MethylPiperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-BiPhenyl And 4,4′-Bis[3-(2,2,6,6-TetraMethylPiperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-BiphenYl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
As part of a comprehensive program to discover α9α10 nicotinic acetylcholine receptor antagonists, the title compounds C30H36N2, (I), and C36H48N2, (II), were synthesized by coupling 4,4′-bis(3-bromoprop-1-yn-1-yl)-1,1′-biphenyl with 4-methylpiperidine and 2,2,6,6-tetramethylpiperidine, respectively, in acetonitrile at room temperature. In compound (I), the biphenyl system has a twisted conformation with a dihedral angle of 26.57 (6)° between the two phenyl rings of the biphenyl moiety, while in compound (II), the biphenyl moiety sits on a crystallographic inversion centre so the two phenyl rings are exactly coplanar. The terminal piperidine rings in …
Comparison Crystal Structure Conformations Of Two Structurally Related Biphenyl Analogues: 4,4'-Bis[3-(Pyrrolidin-1-Yl)Prop-1-Yn-1-Yl]-1,1'-Biphenyl And 4,4'-Bis{3-[(S)-2-Methylpyrrolidin-1-Yl]Prop-1-Yn-1-Yl}-1,1'-Biphenyl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks
Comparison Crystal Structure Conformations Of Two Structurally Related Biphenyl Analogues: 4,4'-Bis[3-(Pyrrolidin-1-Yl)Prop-1-Yn-1-Yl]-1,1'-Biphenyl And 4,4'-Bis{3-[(S)-2-Methylpyrrolidin-1-Yl]Prop-1-Yn-1-Yl}-1,1'-Biphenyl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compounds, C26H28N2, (I), and C28H32N2, (II), were designed based on the structure of the potent 910 nicotinic acetylcholine receptor antagonist ZZ161C {1,1'-[[1,1'-biphenyl]-4,4'-diylbis(prop-2-yne-3,1-diyl)]bis(3,4-dimethylpyridin-1-ium) bromide}. In order to improve the druglikeness properties of ZZ161C for potential oral administration, the title compounds (I) and (II) were prepared by coupling 4,4'-bis(3-bromoprop-1-yn-1-yl)-1,1'-biphenyl with pyrrolidine, (I), and (S)-2-methylpyrrolidine, (II), respectively, in acetonitrile at room temperature. The asymmetric unit of (I) contains two half molecules that each sit on sites of crystallographic inversion. As a result, the biphenyl ring systems in …
Crystal Structure Of Orthorhombic {Bis-[(Pyridin-2-Yl)Methyl](3,5,5,5-Tetrachloropentyl)Amine-Κ3N,N',N''}Chloridocopper(Ii) Perchlorate, Katherine A. Bussey, Annie R. Cavalier, Jennifer R. Connell, Margaret E. Mraz, Kayode D. Oshin, Tomislav Pintauer, Danielle L. Gray, Sean Parkin
Crystal Structure Of Orthorhombic {Bis-[(Pyridin-2-Yl)Methyl](3,5,5,5-Tetrachloropentyl)Amine-Κ3N,N',N''}Chloridocopper(Ii) Perchlorate, Katherine A. Bussey, Annie R. Cavalier, Jennifer R. Connell, Margaret E. Mraz, Kayode D. Oshin, Tomislav Pintauer, Danielle L. Gray, Sean Parkin
Chemistry Faculty Publications
In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitrogen atoms from the bis[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634 (17), 0.221 (16) and 0.145 (7). In addition, the hetero-scorpionate arm of the bis[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine ligand is disordered over two sets of sites with refined occupancies 0.839 (2) and 0.161 (2). In the crystal, weak Cu⋯Cl interactions between symmetry-related molecules create a dimerization with a chloride occupying the apical …
Comparison Of Crystal Structures Of 4-(Benzo[B]Thiophen-2-Yl)-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole And 4-(Benzo[B]Thiophen-2-Yl)-2-Methyl-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole, Narsimha Reddy Penthala, Nikhil Reddy Madadi, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Comparison Of Crystal Structures Of 4-(Benzo[B]Thiophen-2-Yl)-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole And 4-(Benzo[B]Thiophen-2-Yl)-2-Methyl-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole, Narsimha Reddy Penthala, Nikhil Reddy Madadi, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C19H17N3O3S (I), was prepared by a [3 + 2]cycloaddition azide condensation reaction using sodium azide and l-proline as a Lewis base catalyst. N-Methylation of compound (I) using CH3I gave compound (II), C20H19N3O3S. The benzothiophene ring systems in (I) and (II) are almost planar, with r.m.s deviations from the mean plane = 0.0205 (14) in (I) and 0.016 (2) Å in (II). In (I) and (II), the triazole rings make dihedral angles of 32.68 (5) and 10.43 (8)°, respectively, …
Crystal Structure Of 4,5-Bis-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole Methanol Monosolvate, Nikhil Reddy Madadi, Narsimha Reddy Penthala, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Crystal Structure Of 4,5-Bis-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole Methanol Monosolvate, Nikhil Reddy Madadi, Narsimha Reddy Penthala, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C20H23N3O6·CH3OH, was synthesized by [3 + 2] cycloaddition of (Z)-2,3-bis(3,4,5-trimethoxyphenyl)acrylonitrile with sodium azide and ammonium chloride in DMF/water. The central nitrogen of the triazole ring is protonated. The dihedral angles between the triazole ring and the 3,4,5-trimethoxyphenyl ring planes are 34.31 (4) and 45.03 (5)°, while that between the 3,4,5-trimethoxyphenyl rings is 51.87 (5)°. In the crystal, the molecules, along with two methanol solvent molecules are linked into an R 4 4(10) centrosymmetric dimer by N—H⋯O and O—H⋯N hydrogen bonds.
Crystal Structure Of (E)-13-{4-[(Z)-2-Cyano-2-(3,4,5-Trimethoxyphenyl)Ethenyl]Phenyl}Parthenolide Methanol Hemisolvate, Narsimha Reddy Penthala, Shobanbabu Bommagani, Venumadhav Janganati, Sean Parkin, Peter A. Crooks
Crystal Structure Of (E)-13-{4-[(Z)-2-Cyano-2-(3,4,5-Trimethoxyphenyl)Ethenyl]Phenyl}Parthenolide Methanol Hemisolvate, Narsimha Reddy Penthala, Shobanbabu Bommagani, Venumadhav Janganati, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetrahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-ylidene]methyl}phenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodophenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl}methylidene group as a substituent. The 4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl group on the parthenolide exocyclic double bond is …
Crystal Structure Of 1-Methoxy-2,2,2-Tris(Pyrazol-1-Yl)Ethane, Ganna Lyubartseva, Sean Parkin, Morgan D. Coleman, Uma Prasad Mallik
Crystal Structure Of 1-Methoxy-2,2,2-Tris(Pyrazol-1-Yl)Ethane, Ganna Lyubartseva, Sean Parkin, Morgan D. Coleman, Uma Prasad Mallik
Chemistry Faculty Publications
The title compound, C12H14N6O, consists of three pyrazole rings bound via nitrogen to the distal ethane carbon of methoxy ethane. The dihedral angles between the three pyrazole rings are 67.62 (14), 73.74 (14), and 78.92 (12)°. In the crystal, molecules are linked by bifurcated C—H,H⋯N hydrogen bonds, forming double-stranded chains along [001]. The chains are linked via C—H⋯O hydrogen bonds, forming a three-dimensional framework structure. The crystal was refined as a perfect (0.5:0.5) inversion twin.
Low-Temperature Phase Transitions In A Soluble Oligoacene And Their Effect On Device Performance And Stability, J. W. Ward, K. P. Goetz, A. Obaid, Marcia M. Payne, P. J. Diemer, C. S. Day, John E. Anthony, O. D. Jurchescu
Low-Temperature Phase Transitions In A Soluble Oligoacene And Their Effect On Device Performance And Stability, J. W. Ward, K. P. Goetz, A. Obaid, Marcia M. Payne, P. J. Diemer, C. S. Day, John E. Anthony, O. D. Jurchescu
Chemistry Faculty Publications
The use of organic semiconductors in high-performance organic field-effect transistors requires a thorough understanding of the effects that processing conditions, thermal, and bias-stress history have on device operation. Here, we evaluate the temperature dependence of the electrical properties of transistors fabricated with 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene, a material that has attracted much attention recently due to its exceptional electrical properties. We have discovered a phase transition at T = 205 K and discuss its implications on device performance and stability. We examined the impact of this low-temperature phase transition on the thermodynamic, electrical, and structural properties of both single crystals and thin films …