Chemistry Commons^™

Bis(Μ-1,4-Dihydropyridin-4-One-Κ2o:O)Di-Μperchlorato-Κ4o:O0-Bis[Aqua(1,4-Dihydropyridin-4-One-Κo)Copper(Ii)] Tetraaquabis(1,4-Dihydropyridin-4-One-Κo)Copper(Ii) Tetrakis(Perchlorate) 1,4-Dihydropyridin-4-One Disolvate, Mark M. Turnbull, Christopher Landee, Jan L. Wikaira

Chemistry

The reaction of copper(II) perchlorate hexahydrate with 4-pyridone and pyrazine in 1-propanol serendipitously yielded crystals of the solvated title double salt, [Cu(C5H5NO)2(H2O)4][Cu2(ClO4)2(C5H5NO)4(H2O)2](ClO4)4·2C5H5NO, as a biproduct. The copper cations in both the monometallic complex and the dimeric species exhibit classic Jahn-Teller-like elongations. All coordinating 4-pyridone molecules are in the κ-O coordination mode. The dimeric component exhibits both bridging 4-pyridone and perchlorate ligands. Both complexes and the 4-pyridone molecules are bound together by a network of classical hydrogen bonds. The non-coordinating perchlorate ions were modeled as three-site disordered and one of the coordinating 4-pyridone molecules was modeled as two-site disordered. © 2026 …

Synthesis Of Inorganic Actinide Compounds With Neptunium, Plutonium, And Americium, Travis Kelly Deason

Theses and Dissertations

There is a rush of countries around the world making the switch to greener energy sources. Nuclear energy power plants are an integral part of the shift from fossil fuels, but there are concerns over the best way to handle nuclear waste. Most of the nuclear waste is currently disposed of by incorporating the waste into a glass form through vitrification, but research into alternative waste forms, such as promising crystalline materials, could provide a more robust method of containment. Research on actinide materials is lacking due to the dangers of working with radioactive material and there are few labs …

Crystal Growth, Thermal, Optical, Magnetic And Electrochemical Properties Of Mo2Ta2O11, Md Abdullah Al Muhit, Alevtina A. Maksimova, Sean C. Wechsler, Habiba Binte Kashem, Gopabandhu Panigrahi, Gregory Morrison, Morgan Stefik, Hans Conrad Zur Loye

Faculty Publications

Single crystals of the transition metal oxide Mo2Ta2O11 were grown for the first time using molten flux synthesis. The compound crystalizes in the trigonal space group R 3‾m (no. 166) with lattice parameters a = b = 5.6267(1) Å and c = 25.1424(6) Å and a unit cell volume of 689.36(3) ų. The structure of Mo2Ta2O11 is composed of alternating layers of TaO6 octahedra and MoO4 tetrahedra connected via corner-sharing. CaH2 was used to achieve a partial low temperature reduction of Mo2Ta2O11. The electrochemical lithiation of polycrystalline Mo2Ta2O11 was also investigated for the first time. Mo2Ta2O11 underwent a …

Biochemical, Structural, And Conformational Characterization Of A Fungal Ethylene-Forming Enzyme, Shramana Chatterjee, Joel A. Rankin, Mark A. Farrugia, Simahudeen Bathir J S Rifayee, Christo Z. Christov, Jian Hu, Et. Al.

Michigan Tech Publications

The ethylene-forming enzyme (EFE) from the fungus Penicillium digitatum strain Pd1 was heterologously produced in Escherichia coli and its properties were compared to the extensively characterized bacterial enzyme from Pseudomonas savastanoi strain PK2. Both enzymes catalyze four reactions: the conversion of 2-oxoglutarate (2OG) to ethylene and CO₂, oxidative decarboxylation of 2OG coupled to _L-arginine (_L-Arg) hydroxylation, uncoupled oxidative decarboxylation of 2OG, and the production of 3-hydroxypropionate (3-HP) from 2OG. The strain Pd1 enzyme exhibited a greater ratio of ethylene production over _L-Arg hydroxylation than the PK2 strain EFE. The uncoupled decarboxylation of 2OG and …

Cubr2complexes With 3,5-Disubstituted Pyridine Ligands, Christopher Landee, Diane Dickie, Mark M. Turnbull

Chemistry

Reaction of copper(II) bromide with 3,5-dichloropyridine (3,5-Cl2py) or 3,5-dimethylpyridine (3,5-Me2py) led to the isolation of the coordination polymers catena-poly[[bis(3,5-dichloropyridine)copper(II)]-di-μ-bromido], [CuBr2(C5H3Cl2N)2]n or [CuBr2(3,5-Cl2py)2]n (1), and catena-poly[[bis(3,5-dimethylpyridine) copper(II)]-di-μ-bromido], [CuBr2(C7H9N)2]n or [CuBr2(3,5- Me2py)2]n (2), respectively. The structures are characterized by bibromidebridged chains [d(av.)Cu Cu = 3.93 (9) A ]. In 1, the chains are linked perpendicular to the a axis by non-classical hydrogen bonds and halogen bonds, while in 2, only non-classical hydrogen bonds are observed. © 2025 International Union of Crystallography. All rights reserved.

Crystal Structure Analysis Of 1, 4, 7-Trithia-10, 13-Diazacyclopentadecane-9, 14-Dione, Timothy M.E. Jugovic, Christopher G. Hamaker

Faculty Publications – Chemistry

The compound 1,4,7-trithia-10,13-diazacyclopentadecane-9,14-dione, 1, crystallizes in the space group P2₁/c with a = 9.3608(3) Å, b = 16.0333(5) Å, c = 9.5608(3) Å, β = 113.3521(14)°, and Z = 4. The title molecule forms chains via face-to-face N–H^…O hydrogen bonds. The structure of 1 is also compared to the previously reported oxygen analog, 1,4,7-trioxa-10,13-diazacyclopentadecane-9,14-dione.

Molten Flux Synthesis Of Plutonium (Iv) Silicates K2Pusi2O7 And Rb2Pusi6O15, Travis K. Deason, Gregory Morrison, Amir Mofrad, Jake Amoroso, David Diprete, Theodore M. Besmann, Shanna L. Estes, Hans Conrad Zur Loye

Faculty Publications

Few plutonium containing silicates have been reported in the literature and only one other tetravalent plutonium silicate structure has been reported using the flux growth method. With the goal of understanding actinide incorporation into silicates, we describe herein two new plutonium (IV) silicates, Rb2PuSi6O15 and K2PuSi2O7, synthesized using a mixed alkali chloride/alkali fluoride flux growth. Both structures crystallize in the C2/c space group with lattice parameters a=24.2980(10) Å, b=7.1466(3) Å, c=17.2025(8) Å and 96.6560(10)° for Rb2PuSi6O15, and a=9.9478(2) Å, b=5.59820 (10) Å, c=13.1848(2) Å, and 105.7400(10)° for K2PuSi2O7. Comparisons to the synthesis of other reported alkali actinide silicates (Ce, U, …

Na2B12Si6Se18: A Novel B12-Cluster-Containing Quaternary Selenoborate Framework Material, Gopabandhu Panigrahi, Hunter B. Tisdale, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

We report the successful synthesis of the new quaternary, three-dimensional Na₂B₁₂Si₆Se₁₈ material using a solid-state synthesis route. This compound is characterized by a unique framework structure that features the rare icosahedral [B₁₂]¹⁰⁺ cation which is connected via Si2Se6 polyhedral units into a 3D framework structure with Na+ ions located inside the channels. The Na₂B₁₂Si₆Se₁₈ compound crystallizes in the cubic crystal system in the space group Im, with lattice parameter a = 11.91110(10) Å and unit cell volume of 1689.88(4) ų. …

Examination Of Photoinduced Radicals In Two Crystal Forms Of Triphenylamine Bis-Urea Macrocycles, Md Faizul Islam, Gamage Isuri P. Wijesekera, Ammon J. Sindt, Mark D. Smith, Linda S. Shimizu

Faculty Publications

This study probes two solvates of triphenylamine (TPA) bis-urea macrocycle 1 and their activated structures to evaluate their maximum photoinduced radicals (PIRs), the subsequent decay of the radicals, and their regeneration. The hierarchical assembly of TPAs shows promise in stabilizing less substituted derivatives, potentially expanding the utility of TPAs that lack stabilizing para-substituents. Single crystal structure analysis reveals that host 1 adopts a planar conformation with the two ureas pointing in opposite directions when dimethoxyethane (DME) is encapsulated within the channel. Whereas previously, 1 adopted a bowl-shaped conformation with the two ureas pointing in the same direction (syn …

Salts Of 2-Amino-5-Iodo­Pyridinium, Benjamin A. Mukda, Diane A. Dickie, Mark M. Turnbull

Chemistry

Reaction of 2-amino-5-iodopyridine (5IAP) with concentrated HBr at room temperature yielded 2-amino-5-iodopyridinium bromide, C₅H₆IN₂⁺·Br^- or (5IAPH)Br. The complex formed pale-yellow crystals, which exhibit significant hydrogen bonding between the amino and pyridinium N - H donors and bromide ion acceptors. Halogen bonding is also observed. Similarly, reaction of 5IAP with cobalt(II) chloride in mixed HCl/HBr in 1-propanol yielded 2-amino-5-iodopyridinium (2-amino-5-iodopyridine-κN¹)bromido/chlorido(0.51/2.48)cobalt(II), (C₅H₆IN₂)[CoBr_0.51Cl_2.48(C₅H₅IN₂)] or (5-IAPH)[(5IAP)CoCl_2.48Br_0.51], as blue block-shaped crystals. Two of the three …

Di­Chlorido­Tetra­Kis­(3-Meth­­Oxy­Aniline)Nickel(Ii), Benjamin A. Mukda, Mark M. Turnbull

Chemistry

The reaction of nickel(II) chloride with 3-meth­oxy­aniline yielded di­chlorido­tetra­kis­(3-meth­oxy­aniline)nickel(II), [NiCl₂(C₇H₉NO)₄], as yellow crystals. The Ni^II ion is pseudo-octa­hedral with the chloride ions trans to each other. The four 3-meth­oxy­aniline ligands differ primarily due to different conformations about the Ni—N bond, which also affect the hydrogen bonding. Inter­molecular N—H⋯ Cl hydrogen bonds and short Cl⋯Cl contacts between mol­ecules link them into chains parallel to the b axis.

Preferential Crystallization Of (±)-Pinenyllithium·Tmeda, Alexander N. Erickson, Curtis Haltiwanger, Masoumeh Rahim, Charles M. Garner

Chemistry Faculty Research and Publications

(±)-Pinenyllithium·TMEDA or (tetra­methyl­ethylenedi­amine-κ²N,N′)(η³-6,6-di­methyl-2-methylenebi­cyclo­[3.1.1]hept­yl)lithium, [Li(C₁₀H₁₅)(C₆H₁₆N₂)], is readily pre­pared from β-pinene, butyl­lithium and TMEDA, and the racemic material pre­fer­entially crystallizes even from 96:4 (92% ee) mixtures of (−)- and (+)-β-pinene, respectively. The structure is monomeric, with the geminal-dimethyl bridge of the bicyclic structure shielding one face of the allyl system, restricting the lithium to the opposite face and preventing the Li–all­yl–Li aggregation observed with some other allyl­lithium systems. The symmetry of the allyl system, bond lengths, bond angles and out-of-plane deviations …

Hydrothermal Synthesis Of (C5h14n2)[Cocl4]⸳0.5h2o: Crystal Structure, Spectroscopic Characterization, Thermal Behavior, Magnetic Properties And Biological Evaluation, Sandra Walha, Noureddine Mhadhbi, Basem F. Ali, Abdellah Kaiba, Ahlem Guesmi, Wesam Abd El-Fattah, Naoufel Ben Hamadi, Mark M. Turnbull, Ferdinando Costantino, Houcine Naïli

Chemistry

The organic-inorganic compound (C₅H₁₄N₂)[CoCl₄]⸳0.5H₂O, I, was characterized by various physicochemical techniques. The X-ray diffraction analysis revealed that the compound crystallizes in the centrosymmetric space group C2/c of the monoclinic system. The atomic arrangement the Co(II) complex is built from isolated [CoCl₄]^2– anions, 1-methylpiperazine-1,4-diium [C₅H₁₄N₂]²⁺ cations and free water molecules. The crystal structure study showed that the cohesion of I is assured through N–H···Cl and N–H···O hydrogen bonds giving birth to a 3-D architecture. Hirshfeld surface analysis revealed that Cl···H/H···Cl and …

Structural, Spectroscopic, And Computational Insights From Canavanine-Bound And Two Catalytically Compromised Variants Of The Ethylene-Forming Enzyme, Shramana Chatterjee, Matthias Fellner, Joel A. Rankin, Midhun George Thomas, Simahudeen Bathir Jaber Sathik Rifayee, Christo Christov, Jian Hu, Robert P. Hausinger

Michigan Tech Publications

The ethylene-forming enzyme (EFE) is an Fe(II), 2-oxoglutarate (2OG), and l-arginine (l-Arg)-dependent oxygenase that either forms ethylene and three CO2/bicarbonate from 2OG or couples the decarboxylation of 2OG to C5 hydroxylation of l-Arg. l-Arg binds with C5 toward the metal center, causing 2OG to change from monodentate to chelate metal interaction and OD1 to OD2 switch of D191 metal coordination. We applied anaerobic UV-visible spectroscopy, X-ray crystallography, and computational approaches to three EFE systems with high-resolution structures. The ineffective l-Arg analogue l-canavanine binds to the EFE with O5 pointing away from the metal center while promoting chelate formation by 2OG …

Novel Inhibitors To Mmpl3 Transporter Of Mycobacterium Tuberculosis By Structure-Based High-Throughput Virtual Screening And Molecular Dynamics Simulations, Hetanshi Choksi, Justin Carbone, Nicholas J. Paradis, Lucas Bennett, Candice Bui-Linh, Chun Wu

College of Science & Mathematics Departmental Research

Tuberculosis (TB)-causing bacterium Mycobacterium tuberculosis (Mtb) utilizes mycolic acids for building the mycobacterial cell wall, which is critical in providing defense against external factors and resisting antibiotic action. MmpL3 is a secondary resistance nodulation division transporter that facilitates the coupled transport of mycolic acid precursor into the periplasm using the proton motive force, thus making it an attractive drug target for TB infection. In 2019, X-ray crystal structures of MmpL3 from M. smegmatis were solved with a promising inhibitor SQ109, which showed promise against drug-resistant TB in Phase II clinical trials. Still, there is a pressing need to discover more …

Real-Time Spectroscopic Ellipsometry For Flux Calibrations In Multi-Source Co-Evaporation Of Thin Films: Application To Rate Variations In Cuinse₂ Deposition, Dhurba R. Sapkota, Balaji Ramanujam, Puja Pradhan, Mohammed A. Razooqi Alaani, Ambalanath Shan, Michael J. Heben, Sylvain Marsillac, Nikolas J. Podraza, Robert W. Collins

Electrical & Computer Engineering Faculty Publications

Flux calibrations in multi-source thermal co-evaporation of thin films have been developed based on real-time spectroscopic ellipsometry (RTSE) measurements. This methodology has been applied to fabricate CuInSe₂ (CIS) thin film photovoltaic (PV) absorbers, as an illustrative example, and their properties as functions of deposition rate have been studied. In this example, multiple Cu layers are deposited step-wise onto the same Si wafer substrate at different Cu evaporation source temperatures (TCu). Multiple In₂Se₃ layers are deposited similarly at different In source temperatures (TIn). Using RTSE, the Cu and In₂Se₃ deposition rates are determined as …

Microplate-Like Metal Pyrophosphate Engineered On Ni-Foam Towards Multifunctional Electrode Material For Energy Conversion And Storage, Rishabh Srivastava

Electronic Theses & Dissertations

High clean energy demand, dire need for sustainable development, and low carbon footprints are the few intuitive challenges, leading researchers to aim for research and development for high-performance energy devices. The development of materials used in energy devices is currently focused on enhancing the performance, electronic properties, and durability of devices. Tunning the attributes of transition metals using pyrophosphate (P₂O₇) ligand moieties can be a promising approach to meet the requirements of energy devices such as water electrolyzers and supercapacitors, although such a material’s configuration is rarely exposed for this purpose of study.

Herein, we grow …

Μ-1,6-Dioxo-1,6-Diphenylhexane-3,4-Diolato-Bis[(2,2′-Bipyridine)Chloridocopper(Ii)] Dihydrate A; B; A, Luke Nye, Shane G. Tefler, Mark M. Turnbull

Chemistry

The reaction of CuCl2 with 1,6-diphenyl-1,3,5,6-hexanetetrone and 2,2′-bipyridine (bipy) in ethanol gave crystals of the corresponding bimetallic complex, [Cu2(C18H12O4)Cl2(C10H8N2)2]·2H2O. The molecule is centrosymmetric with each CuII ion coordinated to two oxygen atoms from the tetronediate, two nitrogen atoms from a bipy ligand and one coordinated chloride ion. A water molecule of crystallization forms hydrogen bonds to the chloride ions, linking the molecules into a chain parallel to the bc-face diagonal. © 2023 The Author(s).

A Mixed Phosphine Sulfide/Selenide Structure As An Instructional Example For How To Evaluate The Quality Of A Model, Sean Parkin, Jeremy Cunningham, Brian Rawls, John E. Bender, Richard J. Staples, Shannon Biros

Open Access Publishing Support Funded Articles

This paper compares variations on a structure model derived from an X-ray diffraction data set from a solid solution of chalcogenide derivatives of cis-1,2-bis­(di­phenyl­phosphan­yl)ethyl­ene, namely, 1,2-(ethene-1,2-di­yl)bis­(di­phenyl­phoshpine sulfide/selenide), C₂₆H₂₂P₂S_1.13Se_0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between F _obs ² and F _calc ², plots of |F _obs| vs |F _calc|, residual electron density, checkCIF alerts, pitfalls …

Crystal Structure Of Tert-Butyl 3,6-Diiodocarbazole9-Carboxylate, Elizabeth N. Sielaff, Richard J. Staples, Shannon Biros

Open Access Publishing Support Funded Articles

The mol­ecular structure of tert-butyl 3,6-di­iodo­carbazole-9-carboxyl­ate, C₁₇H₁₅I₂NO₂, features a nearly planar 13-membered carbazole ring with C—I bond lengths of 2.092 (4) and 2.104 (4) Å. The carbamate group has key bond lengths of 1.404 (6) Å (N—C), 1.330 (5) Å (O—C), and 1.201 (6) Å (C=O). The crystal contains inter­molecular π–π inter­actions, as well as both type I and type II inter­molecular I⋯I inter­actions.

Crystal Structure, Electronic Structure, And Optical Properties Of The Novel Li4cdge2s7, A Wide-Bandgap Quaternary Sulfide With A Polar Structure Derived From Lonsdaleite, Andrew J. Craig, Seung Han Shin, Jeong Bin Cho, Srikanth Balijapelly, Jordan C. Kelly, Stanislav S. Stoyko, Amitava Choudhury, Joon I. Jang, Jennifer A. Aitken, A. Sarjeant

Chemistry Faculty Research & Creative Works

The novel quaternary thiogermanate Li₄CdGe₂S₇ (tetralithium cadmium digermanium heptasulfide) was discovered from a solid-state reaction at 750 °C. Single-crystal X-ray diffraction data were collected and used to solve and refine the structure. Li₄CdGe₂S₇ is a member of the small, but growing, class of I₄-II-IV₂-VI₇ diamond-like materials. The compound adopts the Cu₅Si₂S₇ structure type, which is a derivative of lonsdaleite. Crystallizing in the polar space group Cc, Li₄CdGe₂S₇ contains 14 crystallographically unique ions, all residing on …

Synthesis And Physicochemical Characterization Of Noncentrosymmetric Quaternary Sulfides With Potential Nonlinear Optical Applications, Andrew J. Craig

Electronic Theses and Dissertations

In this work, several new quaternary sulfides were synthesized and investigated for their potential applications in optics. Chapter 1 provides an overview of nonlinear optical (NLO) materials in general, including their applications, ideal characteristics, current deficiencies, and strategies for the discovery of new candidate NLO materials, particularly those for use in the infrared (IR). Two families of compounds are investigated in this work, including Ln₃LiTS₇ (3-1-1-7) compounds and I₄-II-IV₂-VI₇ (4-1-2-7) diamond-like semiconductors (DLSs). All products were synthesized via traditional high-temperature, solid-state synthesis and their structures were solved and refined through single crystal …

Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darren Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye

Faculty Publications

A new niobium-doped inorganic scintillating oxyfluoride, Rb₄Ge₅O₉F₆:Nb, was synthesized in single crystal form by high-temperature flux growth. The host structure, Rb₄Ge₅O₉F₆, crystallizes in the orthorhombic space group Pbcn with lattice parameters a = 6.98430(10) Å, b = 11.7265(2) Å, and c = 19.2732(3) Å, consisting of germanium oxyfluoride layers made up of Ge₃O₉ units connected by GeO₃F₃ octahedra. In its pure form, Rb₄Ge₅O₉F₆ shows neither luminescence nor scintillation but when doped …

Collision-Induced Dissociation And Ion Mobility Mass Spectrometry Of Au30(S-Tbu)18 Nanoclusters, Christopher Hood

Honors Theses

Collision Induced Dissociation (CID) and Ion Mobility Mass Spectrometry (IM-MS) are methods used to understand the structural arrangement and stability of large molecules. In this study, the gold nanocluster Au₃₀(S-tBu)₁₈ was dissociated at varying Trap collision energies, and drift time vs mass spectrometry data was plotted to determine the order of cluster fragmentation. Comparing Au₃₀(S-tBu)₁₈ data to that of Au₂₅(SCH₂CH₂Ph)₁₈, the only current nanocluster published with IM-MS data, two distinctly different dissociation patterns were seen. Unlike the linear CID fragmentation of Au …

Crystal Structure Of 2-(2,6-Diisopropylphenyl)-N,Ndiethyl- 3,3-Dimethyl-2-Azaspiro[4.5]Decan-1- Amine: A Diethylamine Adduct Of A Cyclic(Alkyl)- (Amino)Carbene (Caac), Roxanne A. Naumann, Joseph W. Ziller, Allegra Liberman-Martin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The structure of the title compound, C₂₇H₄₆N₂, at 93 K has monoclinic (P2₁/n) symmetry. The title compound was prepared by treatment of 2-(2,6-diiso­propyl­phenyl)-3,3-dimethyl-2-aza­spiro­[4.5]dec-1-en-2-ium hydrogen dichloride with two equivalents of lithium di­ethyl­amide. Characterization of the title compound by single-crystal X-ray diffraction and ¹H and ¹³C NMR spectroscopy is presented. Formation of the di­ethyl­amine adduct of the cyclic(alk­yl)(amino)­carbene (CAAC) was unexpected, as deprotonation using lithium diiso­propyl­amide results in free CAAC formation.

Cyclobutanone Inhibitor Of Cobalt-Functionalized Metallo-Γ-Lactonase Aiia With Cyclobutanone Ring Opening In The Active Site, Cory T. Reidl, Romila Mascarenhas, Thahani S. Habeeb Mohammad, Marlon R. Lutz Jr, Pei W. Thomas, Walter Fast, Dali Liu, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

An α-amido cyclobutanone possessing a C10 hydrocarbon tail was designed as a potential transition-state mimetic for the quorum-quenching metallo-γ-lactonase autoinducer inactivator A (AiiA) with the support of in-house modeling techniques and found to be a competitive inhibitor of dicobalt(II) AiiA with an inhibition constant of Ki = 0.007 ± 0.002 mM. The catalytic mechanism of AiiA was further explored using our product-based transition-state modeling (PBTSM) computational approach, providing substrate-intermediate models arising during enzyme turnover and further insight into substrate–enzyme interactions governing native substrate catalysis. These interactions were targeted in the docking of cyclobutanone hydrates into the active site of …

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 Tris, Colin T. Hartgerink, Richard J. Staples, Carolyn E. Anderson

University Faculty Publications and Creative Works

The title ketenyl­idene, [Au3(C2O)(C26H35O2P)3](C2F6NO4S2), was obtained upon exposure of [2-(di­cyclo­hexyl­phosphino)-2′,6′-dimeth­oxy-1,1′-biphen­yl]gold(I) bis­(tri­fluoro­methane­sulfon­yl)imide to acetic anhydride at elevated temperature. The ketenyl­idene bridge caps the tri-gold cluster. The title compound has provided crystals that upon analysis represent the first tri-gold ketenyl­idene with atomic distances indicative of bonding inter­action between the gold atoms.

Atomic-Resolution 1.3 Å Crystal Structure, Inhibition By Sulfate, And Molecular Dynamics Of The Bacterial Enzyme Dape, Matthew Kochert, Boguslaw P. Nocek, Thahani S. Habeeb Mohammad, Elliot Gild, Kaitlyn Lovato, Tahirah K. Heath, Richard C. Holz, Kenneth W. Olsen, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

We report the atomic-resolution (1.3 Å) X-ray crystal structure of an open conformation of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE, EC 3.5.1.18) from Neisseria meningitidis. This structure [Protein Data Bank (PDB) entry 5UEJ] contains two bound sulfate ions in the active site that mimic the binding of the terminal carboxylates of the N-succinyl-l,l-diaminopimelic acid (l,l-SDAP) substrate. We demonstrated inhibition of DapE by sulfate (IC50 = 13.8 ± 2.8 mM). Comparison with other DapE structures in the PDB demonstrates the flexibility of the interdomain connections of this protein. This high-resolution structure was then utilized as the …

New Iodine-Apatites: Synthesis And Crystal Structure, Evgeny Bulanov, Sergey Petrov, Alexander Knyazev

Turkish Journal of Chemistry

The paper describes methods for the preparation of compounds with an apatite structure containing only iodine atoms in the "halogen" position. The crystal structure of the compounds was refined by the Rietveld method. The resulting apatites have a structure with a space group P63/m and have the following unit cell parameters: Ba4f 1.78(2) Ba6h 2.75(2)(PO4)3I0.04(2) (a = 10.18609(34) Å, c = 7.71113(30) Å, V = 692.889(54) Å3, R = 5.448%), Pb4f 1.82(2)Pb6h 2.75(2)(PO4)3I0.13(2) (a = 9.87882(18) Å, c = 7.43222(16) Å, V = 628.144(26) Å3, R = 8.533 %), Pb4f 1.90(2)Pb6h 2.68(2)(PO4)3I0.16(2) a = 9.87058(48) Å, c = 7.41255(46) Å, …