Chemistry Commons^™

Cyclic Versus Polymeric Supramolecular Architectures In Metal Complexes Of Dinucleating Ligands: Silver(I) Trifluoromethanesulfonate Complexes Of The Isomers Of Bis(Di(1h-Pyrazolyl)Methyl)-1,1′-Biphenyl, James R. Gardinier, Heidi M. Tatlock, Jeewantha S. Hewage, Sergey V. Lindeman

Chemistry Faculty Research and Publications

In the search for new examples of systems that self-assemble into cyclic metal–organic architectures, the six isomers of X,Y′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L_XY, and their silver(I) trifluoromethanesulfonate complexes were prepared. Five of the six silver complexes gave crystals suitable for single crystal X-ray diffraction, with only the microcrystalline derivative of 2,3′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L₂₃, proving to be unsuitable for this analysis. Of the structurally characterized silver(I) complexes, that with L₂₂ showed an unusual trans-spanning chelating coordination mode to silver. At the same time the ligand was also bound to a second silver center …

A Two-Component Protocol For Synthesis Of 3-(2-(Substituted Phenylamino)Thiazol-4-Yl)-2h-Chromen-2-Ones, Aamer Saeed, Mubeen Arif, Madiha Irfan, Michael Bolte

Turkish Journal of Chemistry

An efficient 2-component synthesis of a series of 3-(2-(substituted phenylamino)thiazol-4-yl)-2H-chromen-2-ones (3a--j) was achieved by the reaction of 3-(2-thiocyanatoacetyl)-2H-chromen-2-one (1) with a variety of suitably substituted anilines in 1:1 molar ratio in ethanol. The structures of the products were established by elemental analyses, and UV-vis, FTIR, ^1H and ^{13}C NMR, and mass spectroscopy. 3-(2-(4-Methylphenylamino)thiazol-4-yl)-2H-chromen-2-one (3j) was further characterized by single crystal X-ray diffraction study. This compound, C_{19}H_{14}N_2OS, crystallizes in the orthorhombic space group Pna21, with Z = 4, and unit cell parameters a = 13.0785(11), b = 25.746(2), c = 4.7235(3) Å, \alpha = \beta = \gamma = 90°.

Host–Guest Complex Of Β-Cyclodextrin And Disulfide Form Of 4-Aminothiophenol, Taylor A. Cappadona, Lee M. Daniels, Tasneem A. Siddiquee

Chemistry Faculty Research

An inclusion complex of β-cyclodextrin and 4-aminothiophenol was assembled by hydrophobic interaction of the host (β-cyclodextrin) and guest (4-aminothiophenol). The complex was isolated as crystalline solid and studied by single crystal X-ray diffraction method along with NMR and IR spectroscopy. Two cyclodextrin rings each containing one disulfide form of 4-aminothiophenol were found to pair up by hydrogen bonding of the outer rim -OH groups. The phenyl disulfide moiety of 4-aminophenyl disulfide molecule was found in the core of β-cyclodextrin, while the amino functional groups were positioned to the exterior of the cyclodextrin ring. Phenyl rings of the guest molecule from …

Synthesis, Crystal Structure, And Rearrangements Of Ortho-Cyclophane Cyclotetraveratrylene (Cttv) Tetraketone, Marlon R. Lutz Jr., Matthias Zeller, Samuel R.S. Sarsah, Artur Filipowicz, Hailey Wouters, Daniel Becker

Chemistry: Faculty Publications and Other Works

Oxidation of cyclotetraveratrylene (CTTV) with potassium permanganate in pyridine under reflux gave tetraketone (the [14]ketonand) 3 which exists as a previously unobserved barrel conformation with S4symmetry in the crystal structure, although the more familiar ‘boat’ conformer was shown by semi-empirical AM1 calculations to be 3.03 kcal/mol lower in energy. In addition to CTTV tetraketone 3, an isomeric bis-spirolactone 4 was isolated from the basic oxidation conditions, analogous to the product of trans-annular attack and rearrangement observed with oxidation of cyclotriveratrylene, whereas in acid at elevated temperatures, tetraketone 3 underwent a very efficient rearrangement and decarboxylation to afford the highly symmetric …

Synthesis And Structural X-Ray Analysis Of 1,1'-(Naphthalene-1,8-Diyl)-3,3'-Dibenzoyl-Bisthiourea And Its Use As Anion-Binding Receptor, Fatma Aydin, Nazan Tunoğlu, Doğan Aykaç, Nahi̇de Burcu Arslan, Canan Kazak

Turkish Journal of Chemistry

A novel artificial receptor, 1,1'-(naphthalene-1,8-diyl)-3,3'- dibenzoyl-bisthiourea, based on a 1,8-naphthalene skeleton bearing bisthiourea groups was prepared and characterized by IR and ^1H-NMR, ^{13}C-NMR, and MS spectroscopic techniques. The compound proved to be an efficient and selective naked-eye detector for the fluoride, cyanide, and hydroxide ions in DMSO. The crystal structure of the title compound was examined by using X-ray crystallographic techniques and found to be crystallized in the monoclinic space group P -1 with the unit cell parameters: a = 8.1556(8) Å, b = 12.0127(11) Å, c = 13.2081(11) Å, \alpha = 109.510(7)°, \beta = 95.390(7)°, \gamma = 103.660(7)°, Z …

5a-Butyl-1,3,8,10-Tetra-Chloro-7,13-Bis-(4-Nitro-Benzo-Yl)-5a,6a,12a,12b-Tetra-Hydro-7h,13h-Thieno[2,3-B:4,5-B']Bis-(1,4-Benzoxazine), Kai Tang, Margaret E. Kastner

Faculty Journal Articles

The title compound, C(34)H(24)Cl(4)N(4)O(8)S, is a linear penta-cyclic system formed of two substituted benzoxazinyl groups fused to 2-n-butyl-tetra-hydro-thio-phene. The oxazine ring, which is fused to the n-butyl-substituted side of the thio-phene ring, is in a boat conformation. The other fused oxazine ring and the tetra-hydro-thiene ring are each in an envelope conformation. The bridgehead C atom alpha to both the S and N atoms forms the flap of each envelope. This results in a twist of the penta-cyclic system such that the dihedral angle between the terminal dichloro-benzene rings is 82.92 (8)°. In the crystal, inversion-related mol-ecules form a weakly …

Synthesis And Structure Of A Substituted Pyridazine, Kiranmai Byrichetti

Masters Theses & Specialist Projects

Pyridazines are heterocyclic compounds with an N-N bond in their ring structure. Heterocyclic aromatic compounds are of great interest as a result of their novel properties and commercial applications. Our current research is focused on the potential role of pyridazines in next generation electronic devices that utilize organics as the semiconducting material. The synthesis of 5, 6-fused ring pyridazines beginning from fulvenes (Scheme 1) is described herein. These fused heterocycles will serve as synthetic models and building blocks for potential organic or organometallic conducting polymers.

Our goal was to modify the route of Snyder et al. previously reported for the …

Polymorphs And Hydrates Of Acyclovir, Katie M. Lutker, Rosalynn Quiñones-Fernández, Jiadi Xu, Ayyalusamy Ramamoorthy, Adam J. Matzger

Chemistry Faculty Research

Acyclovir (ACV) has been commonly used as an antiviral for decades. Although the crystal structure of the commercial form, a 3:2 ACV/water solvate, has been known since 1980s, investigation into the structure of anhydrous ACV has been limited. Here, we report the characterization of four anhydrous forms of ACV and a new hydrate in addition to the known hydrate. Two of the anhydrous forms appear as small needles and are stable to air exposure, whereas the third form is morphologically similar but quickly absorbs water from the atmosphere and converts back to the commercial form. The high-temperature modification is achieved …

[Diphenyldi(Pyrazol-1-Yl)Methane]Dinitratocobalt(Ii), Janet L. Shaw, Bruce C. Noll

Faculty Articles

In the title compound, [Co(NO₃)₂(C₁₉H₁₆N₄)], the diphenyldipyrazolylmethane ligand coordinates to Co^II in a bidentate fashion forming a six-membered ring with an approximate boat configuration. The mean planes of the two pyrazolyl rings are separated by an angle of 39.6 (2)°. The coordination at the Co^II center is best described as distorted octahedral with two NO₃^- anions serving as bidentate ligands for charge balance. The dihedral angle between the mean planes of the two nitrate rings is 85.0 (1)° and that between the mean planes of the …

Sequence And Structural Analysis Of The Chitinase Insertion Domain Reveals Two Conserved Motifs Involved In Chitin Binding, Hai Li, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Background: Chitinases are prevalent in life and are found in species including archaea, bacteria, fungi, plants, and animals. They break down chitin, which is the second most abundant carbohydrate in nature after cellulose. Hence, they are important for maintaining a balance between carbon and nitrogen trapped as insoluble chitin in biomass. Chitinases are classified into two families, 18 and 19 glycoside hydrolases. In addition to a catalytic domain, which is a triosephosphate isomerase barrel, many family 18 chitinases contain another module, i.e., chitinase insertion domain. While numerous studies focus on the biological role of the catalytic domain in chitinase activity, …

Structural Evidence For Consecutive Hel308-Like Modules In The Spliceosomal Atpase Brr2, L. Zhang, T. Xu, Corina Maeder, L.-O. Bud, J. Shanks, J. Nix, C. Guthrie, J. A. Pleiss, R. Zhao

Chemistry Faculty Research

Brr2 is a DExD/H-box helicase responsible for U4/U6 unwinding during spliceosomal activation. Brr2 contains two helicase-like domains, each of which is followed by a Sec63 domain with unknown function. We determined the crystal structure of the second Sec63 domain, which unexpectedly resembles domains 4 and 5 of DNA helicase Hel308. This, together with sequence similarities between Brr2's helicase-like domains and domains 1-3 of Hel308, led us to hypothesize that Brr2 contains two consecutive Hel308-like modules (Hel308-I and Hel308-II). Our structural model and mutagenesis data suggest that Brr2 shares a similar helicase mechanism with Hel308. We demonstrate that Hel308-II interacts with …

Structural Study On Ammonia Borane For Hydrogen Storage, William Joseph James, L. Jagat, Q. Cai, William B. Yelon, J. B. Yang

Chemistry Faculty Research & Creative Works

Ammonia borane (BH3NH3) is a promising hydrogen storage material because of its high gravimetric (19.6 wt.% H2) and volumetric hydrogen density with an accompanying moderate decomposition temperature. Previously reported structures determined by using x-ray and neutron diffraction on hydrides show differences in bond lengths and atomic coordination. Here, the crystal structures of fully and half deuterated ammonia borane were investigated as a function of temperature using powder neutron diffraction. the neutron diffraction patterns show a significant difference due to large difference in the scattering length of D and H. It is evident that an order-disorder phase transition occurs around 225 …

Synthesis And Crystal Structure Of Pilloin, Hong-Bing Yang, Yan-Chang Wang, Zun-Ting Zhang, Yong Chang

Turkish Journal of Chemistry

Pilloin was synthesized by methylation of luteolin and its structure was characterized by element analysis, ^1H-NMR, IR, and single-crystal X-ray diffraction analysis. It crystallizes in the monoclinic crystal system, space group P2_1/n, with a = 7.336(3) Å, b = 14.257(5) Å, c = 13.298(5) Å, \beta = 93.516(5)°. The flavone molecules of pilloin are linked into puckering sheets via R_3^3(14) and R_2^2(9) graph-set ring motifs defined by the C-H...O and O-H...O hydrogen bonds. \pi -\pi stacking interactions lead to the flavone skeletons of columns that are held together through centrosymmetric R_2^2(8) motifs. Hydrogen bonding and aromatic \pi -\pi stacking interactions …

Exploration Of New Ternary Gallides And Investigation Of Their Structure-Property Relationships, Jung Young Cho

LSU Doctoral Dissertations

This dissertation focuses on the investigation of new ternary intermetallic gallides, which may exhibit exotic physical properties such as heavy-fermion behavior, large magnetoresistance, and even superconductivity. In particular, the Ln-Cu-Ga (Ln = lanthanides) system has been systematically investigated by changing a reaction ratio and/or using a different temperature profile to optimize desired phases. Single crystals of Ln2MGa12 (Ln = La, Ce; M = Ni, Cu) have been synthesized using Ga flux and compared to their Pd analogues. Interestingly, Ce2MGa12 (M = Ni, Cu) show enhanced Sommerfeld coefficient of ¡Ö 191 mJmol-1K-2 and ¡Ö 69 mJmol-1K-2 for Ni and Cu compounds, …

The Syntheses And Electrochemical Performance Of Nano-Mno2 For Supercapacitor, Jun Ma, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Nano-manganese dioxide were prepared by two different methods which are low temperature solid reaction and chemical deposition.The products were characterized by XRD,SEM,BET and constant current charge-discharge tests.The result shows that there is a close relationship between specific capacitance and BET surface areas.Meanwhile the specific capacitance was impacted little by the structure of the nano-manganese dioxides.However,the product performance of high rates,was influenced by structure,the higher rate can be obtained with the more perfect crystal structure.

Functionalization Of Resorcinarenes And Study Of Antimicrobial Activity, Kirankirti Muppalla

USF Tampa Graduate Theses and Dissertations

Cavitands are very important class of compounds in supramolecular chemistry. These molecules contain rigid enforced cavity,and have attracted considerable attention in supramolecular chemistry as building blocks for the construction of carcerands, hemicarcerands, and other host guests complexes. Nearly 40 years ago, Niederl and Vogel laid foundation for the study of such type of condensation reactions. In our laboratory we are involved in synthesis of resorcinarenes with readily available substrates such as resorcinol and aldehydes to form a cyclic tetramer.

Herein, I present detailed studies about the functionalization of the synthesized tetramers and their antimicrobial activity. Octahydroxy resorcinarenes were synthesized and …

Sequence-Specific Recognition And Cooperative Dimerization Of N-Terminal Aromatic Peptides In Aqueous Solution By A Synthetic Host, Lisa M. Heitmann, Alexander B. Taylor, P John Hart, Adam R. Urbach

Chemistry Faculty Research

This article describes the selective recognition and noncovalent dimerization of N-terminal aromatic peptides in aqueous solution by the synthetic host compound, cucurbit[8]uril (Q8). Q8 is known to bind two aromatic guests simultaneously and, in the presence of methyl viologen, to recognize N-terminal tryptophan over internal and C-terminal sequence isomers. Here, the binding of Q8 to aromatic peptides in the absence of methyl viologen was studied by isothermal titration calorimetry (ITC), ¹H NMR spectroscopy, and X-ray crystallography. The peptides studied were of sequence X-Gly-Gly, Gly-X-Gly, and Gly-Gly-X (X = Trp, Phe, Tyr, and His). Q8 selectively binds and dimerizes Trp-Gly-Gly …

Crystal Growth And The Search For Highly Correlated Ternary Intermetallic Antimonides And Stannides, Evan Lyle Thomas

LSU Doctoral Dissertations

This dissertation describes the crystal growth, chemical structures, and efforts made towards the understanding of the physical properties of novel ternary rare-earth intermetallics, which may display signature behavior such as superconductivity, heavy fermion behavior, intermediate valence, and/or large magnetoresistance. To address the problem of correlating these characteristics with structural features, several ternary antimony- and tin-containing phases, Ln-T-X (Ln = lanthanide; T = Co, Ni, Pd; X = Sn, Sb), have been synthesized in single crystalline form by metallic flux-growth methods and characterized by X-ray diffraction. The antimonide compounds LnNi1-xSb2 (Ln = Y, Gd-Tb, Er, Yb), alpha, beta-LnNiSb3 (Ln = La, …

Synthesis And Crystal Structure Of 1,3-Bis(5-Formylpyrrol-2-Yl)Benzene And Its Conversion To A Macrocyclic Derivative, M. Kasim Şener, Davi̇d Sanches Garcia, Mehmet Akkurt, Sema Öztürk Yildirim, Hoong-Kun Fun, Jonathan L. Sessler

Turkish Journal of Chemistry

This report details the synthesis and characterization of a new diformyl pyrrole derivative 2 and its macrocyclic derivative 3. The new compounds were characterized by FT-IR, ^{13}C NMR, and ^1H NMR spectroscopies and via mass spectrometric analysis. The structure of 2 in the solid state was determined using X-ray diffraction methods (monoclinic, P2_1/c, a = 17.3760(7), b = 4.9719(2), c = 15.5374(5) Å, \beta = 105.892(2) °, V = 1291.00(9) Å^3, and Z = 4). The molecular structure is stabilized by N-H...O and C-H...O intermolecular hydrogen bonds. The present bisformylpyrrole derivative 2 provides a new precursor that may be useful …

The Mechanism And Crystal Structure Of 2-Methoxy-2-Methyl-4-Phenyl-3,4,4a, 10b-Tetrahydro-2h,5h-Pyrano[3,2-C]Chromen-5-One. Acetal Of Warfarin Acid, Saira Shahzadi, Saqib Ali, Irum Asif, Rizwana Ashraf, Guo-Xin Jin

Turkish Journal of Chemistry

Acetal of warfarin acid has been synthesized via a hemi acetal intermediate and structurally characterized by X-ray diffraction. The crystal structure shows that the title compound was formed by the hydrolysis of warfarin acid in methanol at pH 3, with space group P2_1/n and unit cell parameters a = 5.859 (17), b =16.745 (5), c = 16.402 (5) Å, \alpha = 90.00; \beta = 94.853 (4), and \gamma = 90.00°.

Synthesis And Reactivity Of Tricarbonyl(1-Methoxycarbonyl-5-Phenylpentadienyl)Iron(1+) Cation, Subhabrata Chaudhury, William A. Donaldson, Dennis W. Bennett, Daniel T. Haworth, Tasneem Siddiquee, Jennifer M. Kloss

Chemistry Faculty Research and Publications

Tricarbonyl(1-methoxycarbonyl-5-phenylpentadienyl)iron(1+) hexafluorophosphate (7) was prepared in two steps from tricarbonyl(methyl 6-oxo-2,4-hexadienoate)iron. While addition of carbon and heteroatom nucleophiles to 7 generally occurs at the phenyl-substituted dienyl carbon to afford (2,4-dienoate)iron products, the addition of phthalimide proceeded at C2 to afford a (pentenediyl)iron product (18). Complex 18 was structurally characterized by X-ray diffraction analysis.

The reaction of the title cation with carbon and heteroatom nucleophiles was examined. In general, the products arise from nucleophilic attack at C5 to give E,E- or E,Z-dienoate iron complexes. Addition of phthalimide anion proceeds at C2 …

An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül

Turkish Journal of Chemistry

2,2'-Bipyridyl-3,3'-dicarboxylic acid (H_2BDC) spontaneously resolves on crystallization from water, giving monohydrated crystals of the space group P2_12_12_1. In any individual crystal, all the atropisomeric-skewed molecules are of one hand; however, on dissolution in water, optical activity is lost. Strong hydrogen bonding leads to a helical structure, via O--H ... N links, and 3 further strong bonds between water and carboxylate groups produce a framework structure. The pK_a values measured for H_2BDC (3.18 \pm 0.04 and 4.59 \pm 0.02 at 20 \pm 1 °C, in dilute aqueous solution) agree with the zwitterionic form. The reaction of H_2BDC with potassium tetrachloroplatinate(II) in …

A New Layered Iron Fluorophosphates, Amitava Choudhury

Chemistry Faculty Research & Creative Works

A new iron fluorophosphate of the composition, [C₆N₄H₂₁] [Fe₂F₂(HPO₄)₃][H₂PO₄]·2H₂O, I. has been prepared by the hydrothermal route. This compound contains iron fluorophosphate layers and the H₂PO₄^- anions are present in the interlayer space along with the protonated amine and water molecules. The compound crystallizes in the monoclinic space group P2₁/c. (a = 13.4422(10) Å, b = 9.7320(10) Å, c = 18.3123(3) Å, ? = 92.1480°, V = 2393.92(5) ų, Z = 4, …

The Crystalline Structure Of Mm3, A Derivative Of Dapsone, Tommie L. Heltcel

McCabe Thesis Collection

Dapsone is a drug which has recently been discovered as a potential treatment for the disease of leprosy. Many of the derivatives of dapsone have been sent to the United States by Dr. M. Muhundam and Professor M.S.R. Naidu of the Department of Chemistry, S.V. University, Tirupati, India, for structure analysis. One such derivative is (E)-3-[2-[(4-Chlorophenyl) sulphonyl] ethenyl]-4H-l-benzopyran-4-one, which will hereafter be referred to as MM3. MM3 was synthesized and the initial data for the structural analysis taken in the departments of Physics and Chemistry at S.V. University, Tirupati, India. The drug has been found to have a high antibacterial …

The Aperiodic Crystal Picture And Free Energy Barriers In Glasses, Randall W. Hall, Peter G. Wolynes

Collected Faculty Scholarship

The aperiodic crystal picture associates the glass transition with freezing into a nonperiodic structure. Dynamics in the glassy state involves activated jumps between different aperiodic free energy minima. Activation barriers may be estimated through the use of freezing theory and the theory of dense solids. The results resemble, but are distinct from, free volume theory. Reasonable fits to experimental data are obtained.