Coordinating ability of the heterocycles 1,3-dithia-2-arsa- and stiba-cyclopentanes. Part III. Dithioacid and dithiocarbamate complexes containing a free functional group. Crystal structure of 2-pyrrolidonedithiocarbamate of 1,3-dithia-arsa-cyclopentane

1993 ◽  
Vol 4 (4) ◽  
pp. 313-317 ◽  
Author(s):  
Raymundo Cea-Olivares ◽  
Rubén Alfredo Toscano ◽  
Marcela López ◽  
Patricia García
Keyword(s):  
Crystal Structure ◽  
Functional Group

GRX: a program to search the CSD for functional group exchanges

2005 ◽  
Vol 38 (4) ◽  
pp. 694-696 ◽  
Author(s):  
Jacco van de Streek ◽  
Sam Motherwell
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Functional Group ◽  
Cambridge Structural Database ◽  
Structural Database

In order to establish the effect of exchanging one functional group by another on the crystal structure, one would like to be able to search the Cambridge Structural Database for all pairs of crystal structures where this substitution has been made. A program calledGRX(group exchange) was written for that purpose.

scholarly journals Crystal Structure of the ECH2 Catalytic Domain of CurF from Lyngbya majuscula

2007 ◽  
Vol 282 (49) ◽  
pp. 35954-35963 ◽  
Author(s):  
Todd W. Geders ◽  
Liangcai Gu ◽  
Jonathan C. Mowers ◽  
Haichuan Liu ◽  
William H. Gerwick ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Functional Group ◽  
Catalytic Domain ◽  
Acyl Carrier Protein ◽  
Cyclopropane Ring ◽  
Chemical Diversity ◽  
Site Directed Mutagenesis ◽  
Lyngbya Majuscula ◽  
Multifunctional Protein ◽  
Curacin A

Curacin A is a mixed polyketide/nonribosomal peptide possessing anti-mitotic and anti-proliferative activity. In the biosynthesis of curacin A, the N-terminal domain of the CurF multifunctional protein catalyzes decarboxylation of 3-methylglutaconyl-acyl carrier protein (ACP) to 3-methylcrotonyl-ACP, the postulated precursor of the cyclopropane ring of curacin A. This decarboxylase is encoded within an “HCS cassette” that is used by several other polyketide biosynthetic systems to generate chemical diversity by introduction of a β-branch functional group to the natural product. The crystal structure of the CurF N-terminal ECH2 domain establishes that the protein is a crotonase superfamily member. Ala78 and Gly118 form an oxyanion hole in the active site that includes only three polar side chains as potential catalytic residues. Site-directed mutagenesis and a biochemical assay established critical functions for His240 and Lys86, whereas Tyr82 was nonessential. A decarboxylation mechanism is proposed in which His240 serves to stabilize the substrate carboxylate and Lys86 donates a proton to C-4 of the acyl-ACP enolate intermediate to form the Δ2 unsaturated isopentenoyl-ACP product. The CurF ECH2 domain showed a 20-fold selectivity for ACP-over CoA-linked substrates. Specificity for ACP-linked substrates has not been reported for any other crotonase superfamily decarboxylase. Tyr73 may select against CoA-linked substrates by blocking a contact of Arg38 with the CoA adenosine 5′-phosphate.

scholarly journals Crystal structure of 5,5′-bis(dimethylamino)-N,N′-(3-methyl-3-azapentane-1,5-diyl)di(naphthalene-1-sulfonamide)

2015 ◽  
Vol 71 (12) ◽  
pp. o959-o960 ◽  
Author(s):  
Toyketa V. Horne ◽  
Syed A. Haque ◽  
Adrianne Barton ◽  
Md. Alamgir Hossain
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dihedral Angle ◽  
Tertiary Amine ◽  
Title Compound ◽  
Functional Group ◽  
Compound C ◽  
Hydrogen Bonding Interactions ◽  
Acceptor Atom ◽  
Dansyl Derivatives

In the title compound, C29H37N5O4S2, two arms substituted with dansyl derivatives are connected to a central tertiary amine, where the dihedral angle between the planes of two dansyl units is 56.39 (4)°. Each arm contains a sulfonamide functional group and both N—H groups in the compound are pointed to the same side. The central part of the molecule is disordered over three sets of sites with a refined occupancy ratio of 0.547 (4):0.328 (4):0.125 (3). No intramolecular π–π or hydrogen-bonding interactions are observed. In the crystal, molecules are linkedviapairs of N—H...O interactions involving the same acceptor atom, forming inversion dimers. In addition, C—H...O interactions exist between molecules, providing further stabilization of dimers.

Effect of Polyaniline on Structural and Optical Characteristics of Fe3O4 and TiO2 Nanoparticles

2020 ◽  
Vol 851 ◽  
pp. 9-15
Author(s):  
Ahmad Taufiq ◽  
M.Sofiyudin Nuroni ◽  
Nurul Hidayat ◽  
ST.Ulfawanti Intan Subadra ◽  
Sunaryono ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Data Analysis ◽  
Diffraction Data ◽  
Functional Group ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray

In this work, Fe3O4 nanoparticles (NPs) were synthesized using coprecipitation method and TiO2 NPs were synthesized using sonication method. Fe3O4/polyaniline and TiO2/polyaniline nanocomposites (NCs) were synthesized using polymerization methods. The samples were characterized by X-ray diffractometer, Fourier-transform infrared spectroscopy, and ultraviolet-visible spectroscopy. The results of X-ray diffraction data analysis presented that polyaniline decreased the crystallinity of Fe3O4 and TiO2 NPs. However, the crystal structure of Fe3O4 and TiO2 NPs did not change, which successively formed the cubic spinel and the tetragonal anatase phases. Furthermore, the functional groups of Ti-O-Ti and Fe-O were detected in the wavenumber ranges of 620-580 cm-1 and 410-520 cm-1, respectively. The presence of polyaniline was also detected by the emergence of a functional group of polyaniline which also showed that there was an interaction of Fe3O4 and TiO2 NPs with polyaniline. Meanwhile, the results of UV-Vis data analysis showed that the addition of polyaniline decreased the bandgap energy of Fe3O4 and TiO2 NPs significantly from 2.186 to 2.174 eV and from 3.374 to 3.320 eV, respectively.

scholarly journals Computation-informed optimization of Ni(PyC)₂ functionalization for noble gas separations

2021 ◽  
Author(s):  
Nickolas Gantzler ◽  
Min-Bum Kim ◽  
Alexander Robinson ◽  
Maxwell W. Terban ◽  
Sanjit Ghose ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Adsorption Isotherms ◽  
Room Temperature ◽  
Functional Group ◽  
Noble Gas ◽  
Molecular Simulations ◽  
Gas Separations ◽  
X Ray ◽  
Binding Pockets ◽  
Group Structures

Metal-organic frameworks (MOFs) are promising nanoporous materials for the adsorptive capture and separation of noble gases at room temperature. Among the numerous MOFs synthesized and tested for noble gas separations, Ni(PyC)₂ (PyC = pyridine-4-carboxylate) exhibits one of the highest xenon/krypton selectivities at room temperature. Like lead-optimization in drug discovery, here we aim to tune the chemistry of Ni(PyC)₂, by appending a functional group to its PyC ligands, to maximize its Xe/Kr selectivity. To guide experiments in the laboratory, we virtually screen Ni(PyC-X)₂ (X=functional group) structures for noble gas separations by (i) constructing a library of Ni(PyC-X)₂ crystal structure models then (ii) using molecular simulations to predict noble gas (Xe, Kr, Ar) adsorption and selectivity at room temperature in each structure. The virtual screening predicts several Ni(PyC-X)₂ structures to exhibit a higher Xe/Kr, Xe/Ar, and Kr/Ar selectivity than the parent Ni(PyC)₂ MOF, with Ni(PyC-m-NH₂)₂ among them. In the laboratory, we synthesize Ni(PyC-m-NH₂)₂, determine its crystal structure by X-ray powder diffraction, and measure its Xe, Kr, and Ar adsorption isotherms (298 K). In agreement with our molecular simulations, the Xe/Kr, Xe/Ar, and Kr/Ar selectivities of Ni(PyC-m-NH₂)₂ exceed those of the parent Ni(PyC)₂. Particularly, Ni(PyC-m-NH₂)₂ exhibits a [derived from experimental, equilibrium adsorption isotherms] Xe/Kr selectivity of 20 at dilute conditions and 298 K, compared to 17 for Ni(PyC)₂. According to in situ X-ray diffraction, corroborated by molecular models, Ni(PyC-m-NH₂)₂ presents well-defined binding pockets tailored for Xe and organized along its one-dimensional channels. In addition to discovering the new, performant Ni(PyC-m-NH₂)₂ MOF for noble gas separations, our study illustrates the computation-informed optimization of the chemistry of a "lead" MOF to target adsorption of a specific gas.

scholarly journals Crystal structure of N,N-diisopropyl-4-methylbenzenesulfonamide

2020 ◽  
Vol 76 (7) ◽  
pp. 1018-1021
Author(s):  
Brock A. Stenfors ◽  
Richard J. Staples ◽  
Shannon M. Biros ◽  
Felix N. Ngassa
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Functional Group ◽  
Asymmetric Unit ◽  
Isopropyl Group ◽  
Hydrogen Atoms ◽  
Bond Lengths ◽  
Compound C

The synthesis of the title compound, C13H21NO2S, is reported here along with its crystal structure. This compound crystallizes with two molecules in the asymmetric unit. The sulfonamide functional group of this structure features S=O bond lengths ranging from 1.433 (3) to 1.439 (3) Å, S—C bond lengths of 1.777 (3) and 1.773 (4) Å, and S—N bond lengths of 1.622 (3) and 1.624 (3) Å. When viewing the molecules down the S—N bond, the isopropyl groups are gauche to the aromatic ring. On each molecule, two methyl hydrogen atoms of one isopropyl group are engaged in intramolecular C—H...O hydrogen bonds with a nearby sulfonamide oxygen atom. Intermolecular C—H...O hydrogen bonds and C—H...π interactions link molecules of the title compound in the solid state.

scholarly journals Crystal structure of 1-ethyl-3-(2-oxo-1,3-dithiol-4-yl)quinoxalin-2(1H)-one

2018 ◽  
Vol 74 (7) ◽  
pp. 901-904 ◽  
Author(s):  
Nicolas Chrysochos ◽  
Carola Schulzke
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Functional Group ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network ◽  
Bonding Interaction ◽  
Weak Hydrogen Bonds

The title compound I, C13H10N2O2S2, crystallizes in the monoclinic space group C2/c with eight molecules in the unit cell. Excluding for the ethyl substituent, the molecule of I adopts a nearly coplanar conformation (r.m.s. deviations is 0.058 Å), which is supported by the intramolecular C—H...O hydrogen-bonding interaction between the two ring systems [C...O = 2.859 (3) Å]. In the crystal, the molecules form dimeric associates via two bifurcated C—H...O hydrogen-bonding interactions between an ene hydrogen atom and a carbonyl functional group of an adjacent molecule [C...O = 3.133 (3) Å] and vice versa. The crystal structure is further stabilized by a three-dimensional network of weak hydrogen bonds between one molecule and six adjacent molecules as well as offset π–π stacking. The combination of the quinoxaline 2(1H)-one moiety with the dithiocarbonate moiety extends the aromaticity of the quinoxaline scaffold towards the substituent as well as influencing the π-system of the quinoxaline. The title compound is the direct precursor for a dithiolene ligand mimicking the natural cofactor ligand molybdopterin.

scholarly journals Crystal structures ofp-substituted derivatives of 2,6-dimethylbromobenzene with ½ ≤Z′ ≤ 4

2016 ◽  
Vol 72 (12) ◽  
pp. 1762-1767
Author(s):  
Angélica Navarrete Guitérrez ◽  
Gerardo Aguirre Hernández ◽  
Sylvain Bernès
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Functional Group ◽  
Molecular Symmetry ◽  
Asymmetric Unit ◽  
Structure Feature ◽  
Non Covalent Interactions ◽  
Derivatives Of ◽  
Covalent Interactions

The crystal structures of four bromoarenes based on 2,6-dimethylbromobenzene are reported, which are differentiated according the functional groupXplacedparato the Br atom:X= CN (4-bromo-3,5-dimethylbenzonitrile, C9H8BrN), (1),X= NO2(2-bromo-1,3-dimethyl-5-nitrobenzene, C8H8BrNO2), (2),X= NH2(4-bromo-3,5-dimethylaniline, C8H10BrN), (3) andX= OH (4-bromo-3,5-dimethylphenol, C8H9BrO), (4). The content of the asymmetric unit is different in each crystal,Z′ = ½ (X= CN),Z′ = 1 (X= NO2),Z′ = 2 (X= NH2), andZ′ = 4 (X= OH), and is related to the molecular symmetry and the propensity ofXto be involved in hydrogen bonding. In none of the studied compounds does the crystal structure feature other non-covalent interactions, such as π–π, C—H...π or C—Br...Br contacts.

Koordinationschemie perhalogenierter Cyclopentadiene und Alkine, XI [1].Darstellung einiger Cymantrenyl-mono- und bis-thioether mit einer weiteren funktionellen Gruppe am Cyclopentadienylring. Molekülstruktur von [C5Cl2(SMe)2(PPh2)]Mn(CO)3 / Coordination Chemistry of Perhalogenated Cyclopentadienes and Alkynes, XI [1]Synthesis of Some Cymantrene Mono- and Bis-Thioethers with One Additional Functional Group on the Cyclopentadienyl Ring. Molecular Structure of [C5Cl2(SMe)2(PPh2)]Mn(CO)3

1993 ◽  
Vol 48 (5) ◽  
pp. 583-590 ◽  
Author(s):  
Karlheinz Sünkel ◽  
Adrian Blum ◽  
Barbara Wagner
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Coordination Chemistry ◽  
Carboxylic Acid ◽  
Acid Chloride ◽  
Functional Group ◽  
Urea Derivative ◽  
Cyclopentadienyl Complexes ◽  
Work Up

Chiral Cyclopentadienyl Complexes, Crystal StructureThe reaction of [C5Cl4(SMe)]Mn(CO)3 (la) with n-butyllithium and the electrophiles SiMe3Cl, CO2, or PPh2Cl regiospecifically yields the chiral 1,3-disubstituted functional cymantrene thioethers [C5Cl3(SMe)R]Mn(CO)3 (R = SiMe3 (2), COOLi (3a), PPh2 (4)). 3 a can be protonated to give the corresponding carboxylic acid (3b), which in turn can be transformed to the acid chloride [C5Cl3(SMe)(COCl)]Mn(CO)3 (3c). 3c reacts with NaN3 to yield after work-up the urea derivative OC[[NH—C5Cl3(SMe)]Mn(CO)3]2 (3d). Using the cymantrene bisthioethers [C5Cl3(SR)2]Mn(CO)3 (R = Me, 5a, Ph, 5b) as starting materials, the carboxyl derivatives [C5Cl2(SMe)2(COR)]Mn(CO)3 (R = OLi, 6a, OH, 6b, Cl, 6c) and the potential organometallic S,P-chelate ligands [C5Cl2(SR)2(PPh2)]Mn(CO)3 (R = Me, 7a, Ph, 7b) can be obtained. The crystal structure determination of 7a (C22H16O3PS2Cl2Mn, monoclinic, P 21/c, a = 18.714(6) A, b = 9.506(3) A, c = 14.475(3) Α, β = 109.18(2)°, V = 2432.1(12) Α3, Z = 4) shows an orientation of the neighbouring PPh2- and SMe groups, that allows chelation of an additional metal fragment.

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