Chemistry Commons^™

Structural Elements Of An Nrps Cyclization Domain And Its Intermodule Docking Domain, Daniel P. Dowling, Yan Kung, Anna K. Croft, Koli Taghizadeh, Wendy L. Kelly, Christopher T. Walsh, Catherine L. Drennan

Chemistry Faculty Research and Scholarship

Epothilones are thiazole-containing natural products with anticancer activity that are biosynthesized by polyketide synthase (PKS)-nonribosomal peptide synthetase (NRPS) enzymes EpoA–F. A cyclization domain of EpoB (Cy) assembles the thiazole functionality from an acetyl group and L-cysteine via condensation, cyclization, and dehydration. The PKS carrier protein of EpoA contributes the acetyl moiety, guided by a docking domain, whereas an NRPS EpoB carrier protein contributes L-cysteine. To visualize the structure of a cyclization domain with an accompanying docking domain, we solved a 2.03-Å resolution structure of this bidomain EpoB unit, comprising residues M1-Q497 (62 kDa) of the 160-kDa EpoB protein. We find …

Crystal Structure Of Di-Aqua-Bis-(7-Di-Ehtyl-Amino-3-Formyl-2-Oxo-2h-Chromen-4-Olato-Κ(2) O (3), O (4))Zinc(Ii) Dimethyl Sulfoxide Disolvate, Aaron B. Davis, Frank R. Fronczek, Karl J. Wallace

Faculty Publications

The structure of the title coordination complex, [Zn(C₁₄H₁₄NO₄)₂(H₂O)₂]·2C₂H₆OS, shows that the Zn^II cation adopts an octa­hedral geometry and lies on an inversion center. Two organic ligands occupy the equatorial positions of the coordination sphere, forming a chelate ring motif via the O atom on the formyl group and another O atom of the carbonyl group (a pseudo--diketone motif). Two water mol­ecules occupy the remaining coordination sites of the Zn^II cation in the axial positions. The water mol­ecules are each hydrogen bonded to …

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′ …

A Novel Copper (Ii) Complex Identified As A Potent Drug Against Colorectal And Breast Cancer Cells And As A Poison Inhibitor For Human Topoisomerase Iiᶐ, Shayna Sandhaus, Rosella Taylor, Tiffany Edwards, Alexis Huddleston, Stephen J. Beebe, Alvin A. Holder

Bioelectrics Publications

A novel complex, [Cu(acetylethTSC)Cl]Cl · 0.25C₂H₅OH 1 (where acetylethTSC = (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide), was shown to have anti-proliferative activity against various colon and aggressive breast cancer cell lines. In vitro studies showed that complex 1 acted as a poison inhibitor of human topoisomerase IIᶐ which may account for the observed anti-cancer effects.

Crystal Structure Of Ethyl 4-[(E)-(4-Hy-Droxy-3-Meth-Oxy-Benzyl-Idene)Amino]-Benzoate: A P-Hy-Droxy Schiff Base, Jing Ling, Padmini Kavuru, Lukasz Wojtas, Keith Chadwick

Chemistry Faculty Publications

The title p-hy-droxy Schiff base, C17H17NO4, was synthesized via the condensation reaction of benzocaine with vanillin. The benzyl-idine and benzoate rings are inclined to one another by 24.58 (8)°, and the conformation about the C=N bond is E. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming zigzag chains propagating along [010]. Adjacent chains are linked by C-H⋯π and weak offset π-π inter-actions [inter-centroid distance = 3.819 (1) Å], forming sheets parallel to (10-2).

Synthesis And Photochromism Of New Asymmetrical Diarylethenes With A Variable Heteroaryl Ring And A Quinoline Unit, Hongyan Xu, Renjie Wang, Congbin Fan, Gang Liu, Shouzhi Pu

Turkish Journal of Chemistry

Three new asymmetrical photochromic diarylethenes containing a variable heteroaryl ring and a quinoline unit were synthesized and their structures were determined by single-crystal X-ray diffraction analysis. Their properties, including photochromism, acidichromism, and fluorescence, were investigated systematically. For these diarylethenes, the one with an indole moiety had the largest absorption maximum, cyclization quantum yield, photoconversion ratio, emission peak, and fluorescent modulation efficiency. In addition, these diarylethenes exhibited an evident dual switching behavior induced by the stimulation of acid/base and UV/Vis. Addition of trifluoroacetic acid to solution of the diarylethenes produced protonated derivatives with notable changes in their absorption spectra. These results …

Crystal Structure Of (E)-2-[(2- Bromo-3-Pyridyl)Methylidene]-6-Methoxy-3,4-Dihydronaphthalen-1-One And 3-[(E)-(6- Methoxy-3,4-Dihydronaphth-2-Oylidene)Methyl]-1h-Pyridin-2-One, Sarah K. Zingales, Morgan E. Moore, Andrew D. Goetz, Clifford W. Padgett

Chemistry: Faculty Publications (1990-2023)

The title compounds C17H14BrNO2, (I), and C17H15NO3, (II), were obtained from the reaction of 6-meth­oxy-3,4-di­hydro-2H-naphthalen-1-one and 2-bromo­nicotinaldehyde in ethanol. Compound (I) was the expected product and compound (II) was the oxidation product from air exposure. In the crystal structure of compound (I), there are no short contacts or hydrogen bonds. The structure does display [pi]-[pi] inter­actions between adjacent benzene rings and adjacent pyridyl rings. Compound (II) contains two independent mol­ecules, A and B, in the asymmetric unit; both are non-planar, the dihedral angles between the meth­oxy­benzene and 1H-pyridin-2-one mean planes being 35.07 (9)° in A and 35.28 (9)°in B. In …

X-Ray Structure And Properties Of The Ferrous Octaethylporphyrin Nitroxyl Complex, Nagabhushanam Kundakarla, Sergey V. Lindeman, Hafiz Md. Rahman, Michael D. Ryan

Chemistry Faculty Research and Publications

The preparation and characterization of the iron octaethylporphyrin nitroxyl ion, [Fe(OEP)(NO)⁻], is reported. The complex was synthesized by the one-electron reduction of Fe(OEP)(NO) using anthracenide as the reducing agent. The compound was isolated as the potassium (2.2.2)cryptand salt. The anion was characterized using X-ray analysis with visible and infrared spectroscopy. The spectral features of the iron nitroxyl complex were consistent with previous literature reports. The important structural changes upon reduction were a significant decrease in the Fe–N–O bond angle from 142° to 127° and an increase in the N–O bond length from that in the starting nitrosyl moiety. …

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 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 …

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 …

Synthesis, Crystal Structures, And Dft Calculations Of Three New Cyano(Phenylsulfonyl)Indoles And A Key Synthetic Precursor Compound, William Montgomery, Justin Lopchuk, Gordon Gribble, Jerry Jasinski

Dartmouth Scholarship

Three cyano-1-(phenylsulfonyl)indole derivatives, 3-cyano-1-(phenylsulfonyl) indole, (I), 2-cyano-1-(phenylsulfonyl)indole, (II), and 2,3-dicyano-1-(phenylsulfonyl) indole, (III), and a key synthetic precursor 1-(phenylsulfonyl)-1-(1,1-dimethylethyl) indole-3-carboxamide, (IV), have been synthesized and their structures determined by single crystal X-ray crystallography. (I), C₁₅H₁₀N₂O₂S, is orthorhombic with space group P 2₁2₁2₁ and cell constants: a = 4.9459(3) Å, b = 10.5401(7) Å, c = 25.0813(14) Å, V = 1307.50(14) ų and Z = 4. (II), C₁₅H₁₀N₂O₂S, …

An Investigation On Electrochemical Performance Of Supercapacitor Electrode Materials Prepared By Mno2 With Four Different Crystal Forms, Zhen-Kun Wei, Xiao-Zhen Hua, Ke Xiao, Xian-Liang Zhou, Zhi-Guo Ye

Journal of Electrochemistry

Four types of α-MnO₂, β-MnO₂, γ-MnO₂ and δ-MnO₂ powders were synthesized by relatively simple methods. The differences in crystal structures and surface morphologies for these forms of MnO₂ were investigated by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA) and specific surface area analysis (BET). The electrochemical performances were characterized by cyclic voltammetry (CV) and stability analysis. Based on the experimental results, four kinds of MnO₂ electrodes showed good capacity properties, and the α-MnO₂ electrode had the largest specific capacity due to the highest specific surface …

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 Cu^II 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 …

Crystal Structure Of Cis-2-(2-Carboxycyclopropyl)-Glycine (Ccg-Iii) Monohydrate, Sergey V. Lindeman, Nathaniel J. Wallock, William A. Donaldson

Chemistry Faculty Research and Publications

The title compound, C₆H₉NO₄·H₂O [systematic name: (αR,1R,2S)-rel-α-amino-2-carb­oxy­cyclo­propane­acetic acid monohydrate], crystallizes with two organic mol­ecules and two water mol­ecules in the asymmetric unit. The space group is P2₁ and the organic mol­ecules are enanti­omers, thus this is an example of a `false conglomerate' with two mol­ecules of opposite handedness in the asymmetric unit (r.m.s. overlay fit = 0.056 Å for one mol­ecule and its inverted partner). Each mol­ecule exists as a zwitterion, with proton transfer from the amino acid carb­oxy­lic acid group to …

Crystal Structure Of Catena-Poly[[Chlorido(4,4'-Dimethyl-2,2'-Bipyridine-Κ2n,N')Copper(Ii)]-Μ-Chlorido], Rafaela Nita, Jeffrey R. Deschamps, Scott A. Trammell, D. Andrew Knight

Chemistry and Chemical Engineering Faculty Publications

The title compound, [CuCl2(C12H12N2)]n, was obtained via a DMSO-mediated dehydration of Cu(4,4'-dimethyl-2,2'-bipyridine)copper(II)·0.25H2O. The central CuII atom is coordinated in a distorted trigonal-bipyramidal geometry by two N atoms of a chelating 4,4'-dimethyl-2,2'-bipyridine ligand [average Cu-N = 2.03 (3) Å] and three Cl atoms, one terminal with a short Cu-Cl bond of 2.2506 (10) Å, and two symmetry-equivalent and bridging bonds. The bridging Cl atom links the CuII ions into chains parallel to [001] via one medium and one long Cu-Cl bond [2.3320 (10) and 2.5623 (9) Å]. The structure displays both inter- and intramolecular C-H⋯Cl hydrogen bonding.

The Crystal Structure Of Nitrosomonas Europaea Sucrose Synthase Reveals Critical Conformational Changes And Insights Into The Sucrose Metabolism In Prokaryotes, Rui Wu, Matías D. Asención Diez, Carlos M. Figueroa, Matías Machtey, Alberto A. Iglesias, Miguel Ballicora, Dali Liu

Chemistry: Faculty Publications and Other Works

In this paper we report the first crystal structure of a prokaryotic sucrose synthase from the non-photosynthetic bacterium Nitrosomonas europaea. The obtained structure was in an open form, whereas the only other available structure from the plant Arabidopsis thaliana was in a closed conformation. Comparative structural analysis revealed a “hinge-latch” combination, which is critical to transition between the open and closed forms of the enzyme. The N. europaea sucrose synthase shares the same fold as the GT-B family of the retaining glycosyltransferases. In addition, a triad of conserved homologous catalytic residues in the family showed to be functionally critical …

Synthesis And Characterization Of Substituted Benzimidazole Co(Ii), Fe(Ii), And Zn(Ii) Complexes And Structural Characterization Of Dichlorobis{1-[2-(1-Piperidinyl)Ethyl]-1h-Benzimidazole-_Kn^3} Zinc(Ii), Hasan Küçükbay, Ülkü Yilmaz, Mehmet Akkurt, Orhan Büyükgüngör

Turkish Journal of Chemistry

The Co(II), Fe(II), and Zn(II) complexes of 1-(3-phenyl)propylbenzimidazole (PPBI), 5-nitro-1-(3-phenyl) propylbenzimidazole (PPNBI), 1-[2-(4-morpholinyl)ethyl]benzimidazole (MEBI), 1-[2-(1-piperidinyl)ethyl]benzimidazole (PEBI), and 5-nitro-1-[2-(1-piperidinyl)ethyl]benzimidazole (PENBI) were synthesized and characterized by ^1H NMR, ^{13}C NMR, and elemental analyses. The magnitudes of the magnetic moments for paramagnetic complexes were between 4.07 and 5.11 B.M. Moreover, the crystal structure of dichlorobis{1-[2-(1-piperidinyl)ethyl]-1H-benzimidazole-_KN^3} zinc(II) was determined by single crystal X-ray diffraction.

Crystal Structure Of {2,20-[N,N0-Bis(Pyridin-2-Yl-Methyl)Cyclohexane-Trans-1,2-Diyldi(Nitrilo)]- Diacetato}Cobalt(Iii) Hexafluoridophosphate, Craig C. Mclauchlan, Daniel S. Kissel, Albert W. Herlinger

Faculty Publications – Chemistry

The title compound [Co(C22H26N4O4)]PF6, commonly known as [Co(bpcd)]PF6, where bpcd2- is derived from the historical ligand name N,N'-bis­(2-pyridyl­meth­yl)-trans-1,2-di­amino­cyclo­hexane-N,N'-di­acetate, crystallized by slow evaporation of a saturated aceto­nitrile solution in air. The cation of the hexa­fluorido­phosphate salt has the CoIII atom in a distorted octa­hedral coordination geometry provided by an N4O2 donor atom set. The acetate groups, which are oriented trans with respect to each other, exhibit monodentate coordination whereas the pyridyl N atoms are coordinating in a cis configuration. The geometry of the cation is compared to the geometries of other di­amino …

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

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

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 A Polysamarium (Iii) Nitrate Chain Crosslinked By A Di-Cmpo Ligand, Julie A. Stoscup, Richard J. Staples, Shannon M. Biros

Peer Reviewed Articles

In the title compound poly[aqua­bis­(-nitrato-⁴O,O':O,O'')tetra­kis­(nitrato-²O,O'){₄-tetra­ethyl [(ethane-1,2-diyl)bis(aza­nedi­yl)bis­(2-oxo­ethane-2,1-di­yl)]di­phospho­nate-²O,O'}disamarium(III)], [Sm₂(NO₃)₆(C₁₄H₃₀N₂O₈P₂)(H₂O)]_n, a 12-coordinate Sm^III and a nine-coordinate Sm^III cation are alternately linked via shared bis-bidentate nitrate anions into a corrugated chain extending parallel to the a axis. The nine-coordinate Sm^III atom of this chain is also chelated by a bidentate, yet flexible, carbamoyl­methyl­phoshine oxide (CMPO) ligand and bears one water …

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

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 …

Homochiral Metal-Organic Materials: Design, Synthetic And Enantioseletive Separation, Shi-Yuan Zhang

USF Tampa Graduate Theses and Dissertations

Owing to the growing demand for enantiopurity in biological and chemical processes, tremendous efforts have been devoted to the synthesis of homochiral metal-organic materials (MOMs) because of their potential applications in chiral separation and asymmetric catalysis. In this dissertation, the synthetic strategies for homochiral MOMs are discussed keeping the focus on their applications. Two distinct approaches have been taken to synthesize chiral structures with different topologies and accessible cavities. The chiral MOMs have been utilized in enantioselective separation of racemates.

Chiral variants of the prototypal metal-organic framework MOF-5, δ-CMOF-5 and [lambda]-CMOF-5, have been synthesized by preparing MOF-5 in the presence …

Synthesis, Crystal Structure Refinement, And Electrical Conductivity Of Pb(8−X)Na2smx(Vo4)6o(X/2), Tatiana M. Savankova, Lev G. Akselrud, Lyudmyla I. Ardanova, Alexey V. Ignatov, Eugeni I. Get’Man, Roman E. Gladyshevskii, Stanislav N. Loboda

Biochemistry, Chemistry and Geology Department Publications

Solid solutions of Pb(8−x)Na2Smx(VO4)6O(x/2) were studied using X-ray diffraction analysis including Rietveld refinement and scanning electron microscopy and by measuring their electrical conductivity. Crystal structure of the solid solutions was refined and the solubility region 0 ≤ x ≤ 0.2 was determined for samarium substitution for lead under the scheme 2Pb2+ + ◻ → 2Sm3+ + O2-. The influence of degree of substitution on the electrical conductivity of solid solutions was established.

Design And Study Of The Efflux Function Of The Egfp Fused Mexab-Oprm Membrane Transporter In Pseudomonas Aeruginosa Using Spectroscopy, Feng Ding, Kerry J. Lee, Ardeschir Vahedi-Faridi, Hiroshi Yoneyama, Christopher J. Osgood, Xiao-Hong Nancy Xu

Biological Sciences Faculty Publications

Multidrug membrane transporters (efflux pumps) can selectively extrude a variety of structurally and functionally diverse substrates (e.g., chemotoxics, antibiotics), leading to multidrug resistance (MDR) and ineffective treatment of a wide variety of diseases. In this study, we have designed and constructed a fusion gene (egfp-mexB) of N-terminal mexB with C-terminal egfp, inserted it into a plasmid vector (pMMB67EH), and successfully expressed it in the Δ MexB (MexB deletion) strain of Pseudomonas aeruginosato create a new strain that expresses MexA-(EGFP-MexB)-OprM. We characterized the fusion gene using gel electrophoresis and DNA sequencing, and determined its expression in live …

Synthesis, Structure, And Luminescent Properties Of 2 Novel 5-Chlorhydroxybenzoate-Imidazole Metal-Organic Complexes, Hong Chen, Si Yuan Luo, Xiuling Wu, Yongqian Wang, Bo Hu, Chao Hu, Gang Huang, Qiao Xin Du

Turkish Journal of Chemistry

Two novel Zn and Cu complexes with 5-chlorhydroxybenzoate and imidazole ligands, C_{41}H_{36}Zn_2N_8O_{13}Cl_4 (1) and C_{26}H_{22}Cl_2Cu_2N_8O_6 (2), were prepared by slow evaporation method. Single crystal X-ray diffraction analysis was used to determine their structures. The purity of the complexes was confirmed by powder X-ray diffraction analysis. In 1 the Zn^{2+} cation is tetracoordinated with 2 nitrogen atoms from 2 imidazoles and 2 oxygen atoms from the 2 carboxyl groups in 5-chlorhydroxybenzoate. In 2 the coordination polyhedrons of Cu^{2+} center can be described as distorted square pyramidal geometry sharing common edges, with an oxygen atom on the top of the pyramid. The …

Investigating Intermolecular Interactions In Crystalline Aspirin Using Cdft, Nicholas Turner, Tonglei Li, Mingtao Zhang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Drugs today are widely administered in their crystalline form, namely via tablets and capsules. The crystal structure of a drug molecule affects important drug qualities such as solubility, bioavailability, shelf life, and compaction properties. In order to form a basis for crystal structure prediction, it is necessary to first understand how intermolecular interactions cause molecules to pack in certain ways. Being able to predict and perhaps even control a drug molecule’s crystal structure will lead to the development of higher quality drugs that perform more consistently. Scientists and engineers do not fully understand the reasons for a molecule assuming a …