scholarly journals The arsonomethyl group as an analogue of phosphate. An X-ray investigation

1983 ◽  
Vol 213 (1) ◽  
pp. 217-223 ◽  
Author(s):  
K Kamiya ◽  
W B T Cruse ◽  
O Kennard
Keyword(s):  
Atomic Radius ◽  
British Library ◽  
Barium Salt ◽  
Compound I ◽  
X Ray ◽  
Enzyme Substrates ◽  
Structural Analogues ◽  
Valency Angle ◽  
Compound Ii ◽  
R Factors

The X-ray structure analysis of three compounds of interest as enzyme substrates is reported. They are the hydrated forms of (I) DL-2-amino-4-arsonobutanoic acid [HO–AsO2-–CH2–CH2–CH(NH3+)–CO2H], (II) DL-2-amino-4-phosphonobutanoic acid [HO–PO2-–CH2–CH2–CH(NH3+)–CO2H] and the hydrated barium salt of (III) D-3-phosphoglycerate [HO–PO2-–O–CH2–CH(OH)–CO2-]. The structures were fully refined to R factors of 0.033, 0.053 and 0.046. For the compounds (I) and (II) the charge distribution was directly determined by locating all H atoms. The co-ordination around As and P is approximately tetrahedral, with the valency angle between the two charged O atoms enlarged to 112 degrees in compound (I), 166 degrees in compound (II) and 122 degrees in compound (III). The As-X bond distances are increased relative to P-X to accommodate the increased atomic radius. The analysis establishes that the compounds are structural analogues. Tables of co-ordinates for H atoms, anisotropic thermal parameters, bond lengths and bond angles for the three compounds have been deposited as Supplementary Publication SUP 50122 (5 pages) with the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained directly [see Biochem J. (1983) 209, 5].

Chemistry of the S=O bond. 13. Structures of isomers 1 (I) and 2 (II) of 4-methyl-1,3,2-dioxathiane 2-oxide and 1,3,2-dioxathiepane 2-oxide (III) at 256, 240 and 228 K

1996 ◽  
Vol 52 (3) ◽  
pp. 505-508 ◽  
Author(s):  
D.G. Hellier ◽  
P. Luger ◽  
J. Buschmann
Keyword(s):  
Single Crystals ◽  
Low Temperatures ◽  
Chair Conformation ◽  
Equatorial Position ◽  
X Ray Diffraction ◽  
Compound I ◽  
Methyl Group ◽  
X Ray ◽  
Compound Ii ◽  
Axis Passing

The structures of the two isomers of 4-methyl-1,3,2-dioxathiane 2-oxide, C4H8SO3 (I, II), and 1,3,2-dioxathiepane 2-oxide, C4H8SO3 (III), have been determined by X-ray diffraction methods for single crystals that were grown in this case at low temperatures from the normally liquid compounds. Compound (I): orthorhombic, P212121, Mr = 136.17, a = 7.204 (6), b = 13.670 (11), c = 6.041 (6) Å, V = 594.91 Å3, Z= 4, Dx = 1.520 Mg m−3, Mo Kα (λ = 0.71068 Å), μ = 4.49 cm−1, F(000) = 288, T = 256 K, R = 0.042 for 778 unique reflections. Compound (II): orthorhombic, P212121, Mr = 136.17, a = 18.238 (6), b = 10.265 (3), c = 6.616 (2) Å, V = 1238.60 Å3, Z= 8, Dx = 1.460 Mg m−3, Mo Kα (λ = 0.71068 Å), μ = 4.31 cm−1, F(000) = 576, T = 240 K, R = 0.032 for 1597 unique reflections. Compound (III): monoclinic, P21/n, Mr = 136.17, a = 6.060 (3), b = 11.185 (8), c = 9.186 (4) Å, β = 101.32 (4)°, V = 610.52 Å3, Z = 4, Dx = 1.481 Mg m−3, Mo Kα (λ = 0.71068 Å), μ = 4.38 cm−1, F(000) = 288, T = 228 K, R = 0.037 for 1161 unique reflections. Compound (I) adopts a chair structure, which has a methyl group in an equatorial position and an axially oriented S=O group. Compound (II) is similar, except that the S=O group is equatorially oriented. Compound (III) adopts a twist-chair conformation with a local approximate endocyclic twofold axis passing through S(1) and the middle of the opposite bond, C(4)—C(5).

Structure and photochemical properties of biindenylidene derivatives in the solid state

2008 ◽  
Vol 2008 (11) ◽  
pp. 647-649
Author(s):  
Xu Li ◽  
Ping Wang ◽  
Jing-jun Liu ◽  
Yong-ming Wang ◽  
Hai Zhu
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Organic Radical ◽  
Compound I ◽  
X Ray ◽  
Photochromic Compounds ◽  
X Ray Crystallography ◽  
Photochemical Properties ◽  
Compound Ii

Two photochromic compounds, trans-3,3′-dipentyl-3,3′-dihydroxy-2,2′-bi-1H-indene-1,1′-dione (I), and cis-3,3′-di (2-methylally)-3,3′-dihydroxy-2,2′-bi-1H-indene-1,1′-dione (II), were synthesised and their crystal structures were determined by X-ray crystallography. The photoinduced properties of the compound were studied. The results showed that compound I exhibited reversible photochromism, and at the same time a stable organic radical was generated, while compound II did not show photochemical properties.

scholarly journals Crystal structures of two 1:2 dihydrate compounds of chloranilic acid with 2-carboxypyridine and 2-carboxyquinoline

2017 ◽  
Vol 73 (12) ◽  
pp. 1840-1844 ◽  
Author(s):  
Kazuma Gotoh ◽  
Hiroyuki Ishida
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Picolinic Acid ◽  
Compound I ◽  
Chloranilic Acid ◽  
X Ray ◽  
Disordered Structure ◽  
Compound Ii

The crystal structure of the 1:2 dihydrate compound of chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) with 2-carboxypyridine (another common name: picolinic acid; systematic name: pyridine-2-carboxylic acid), namely, 2C6H5.5NO20.5+·C6HCl2O4−·2H2O, (I), has been determined at 180 K, and the structure of the 1:2 dihydrate compound of chloranilic acid with 2-carboxyquinoline (another common name: quinaldic acid; systematic name: quinoline-2-carboxylic acid), namely, 2C10H7NO2·C6H2Cl2O4·2H2O, (II), has been redetermined at 200 K. This determination presents a higher precision crystal structure than the previously published structure [Marfo-Owusu & Thompson (2014).X-ray Struct. Anal. Online,30, 55–56]. Compound (I) was analysed as a disordered structure over two states,viz.salt and co-crystal. The salt is bis(2-carboxypyridinium) chloranilate dihydrate, 2C6H6NO2+·C6Cl2O42−·2H2O, and the co-crystal is bis(pyridinium-2-carboxylate) chloranilic acid dihydrate, 2C6H5NO2·C6H2Cl2O4·2H2O, including zwitterionic 2-carboxypyridine. In both salt and co-crystal, the water molecule links the chloranilic acid and 2-carboxypyridine molecules through O—H...O and N—H...O hydrogen bonds. The 2-carboxypyridine molecules are connected into a head-to-head inversion dimer by a short O—H...O hydrogen bond, in which the H atom is disordered over two positions. Compound (II) is a 1:2 dihydrate co-crystal of chloranilic acid and zwitterionic 2-carboxyquinoline. The water molecule links the chloranilic acid and 2-carboxyquinoline molecules through O—H...O hydrogen bonds. The 2-carboxyquinoline molecules are connected into a head-to-tail inversion dimer by a pair of N—H...O hydrogen bonds.

scholarly journals Crystal structures ofN-[(4-phenylthiazol-2-yl)carbamothioyl]benzamide andN-{[4-(4-bromophenyl)thiazol-2-yl]carbamothioyl}benzamide from synchrotron X-ray diffraction

2016 ◽  
Vol 72 (9) ◽  
pp. 1343-1347 ◽  
Author(s):  
Ekaterina S. Gantimurova ◽  
Alexander S. Bunev ◽  
Kristina Yu. Talina ◽  
Gennady I. Ostapenko ◽  
Pavel V. Dorovatovskii ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Dihedral Angles ◽  
Active Pharmaceutical Ingredients ◽  
X Ray Diffraction ◽  
Compound I ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
Phenyl Rings ◽  
Compound Ii

The title compounds, C17H13N3OS2, (I), and C17H12BrN3OS2, (II), are potential active pharmaceutical ingredients. Compound (I) comprises two almost planar fragments. The first is the central (carbamothioyl)amide (r.m.s. deviation = 0.038 Å), and the second consists of the thiazole and two phenyl rings (r.m.s. deviation = 0.053 Å). The dihedral angle between these planes is 15.17 (5)°. Unlike (I), compound (II) comprises three almost planar fragments. The first is the centralN-(thiazol-2-ylcarbamothioyl)amide (r.m.s. deviation = 0.084 Å), and the two others comprise the bromophenyl and phenyl substituents, respectively. The dihedral angles between the central and two terminal planar fragments are 21.58 (7) and 17.90 (9)°, respectively. Both (I) and (II) feature an intramolecular N—H...O hydrogen bond, which closes anS(6) ring. In the crystal of (I), molecules form hydrogen-bonded layers parallel to (100) mediated by N—H...S and C—H...O hydrogen bonds. In the crystal of (II), molecules form a three-dimensional framework mediated by N—H...Br and C—H...O hydrogen bonds, as well as secondary S...Br [3.3507 (11) Å] and S...S [3.4343 (14) Å] interactions.

Synthesis and Electrochemical Behavior of Two Microporous Polyoxomolybdates

2009 ◽  
Vol 79-82 ◽  
pp. 1479-1482
Author(s):  
Qi Bao ◽  
Shu Fang Zhang ◽  
Dun Zhang
Keyword(s):  
Electrochemical Properties ◽  
Redox Reactions ◽  
Metal Salt ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Compound I ◽  
X Ray ◽  
Potential Applications ◽  
Compound Ii ◽  
Reaction Processes

Two new microporous polyoxomolybdates of (NH4)2[γ-Mo8O26] (Compound I) and (NH4)2[Mo4O13] (Compound II) were synthesized hydrothermally and characterized by elemental analysis, infra-red, TG analysis and single-crystal X-ray diffraction. In the synthesis process, we found that both organic template and transition metal salt play crucial roles in the formation of crystals. Cyclic voltammetry was used to study their electrochemical properties. The results reveal that the two compounds possess electrochemical activity in 0.2M H2SO4+Na2SO4 ( pH=1 ) solution and three multi-electron transferred redox reaction (I-I´, II-II´ and III-III´) processes were obtained. The first two redox reactions (I-I´, II-II´) are reversible reaction processes but another one (III-III´) is not. The electrochemical properties of the two compounds indicate their great potential applications in electroanalysis and electrocatalysis.

Synthesis and structural characterization of N,N′-diarylpiperazine N,N′-dioxide tetrahydrates (aryl = o-tolyl, p-tolyl, p-chlorophenyl)

1988 ◽  
Vol 66 (8) ◽  
pp. 1836-1847 ◽  
Author(s):  
Chun-Kiu Kwok ◽  
Thomas C. W. Mak
Keyword(s):  
Crystal Packing ◽  
Direct Method ◽  
Water Molecules ◽  
Compound I ◽  
Space Group ◽  
X Ray ◽  
A Site ◽  
Compound Ii

The synthesis and X-ray structure determination of N,N′-di(o-tolyl)piperazine N,N′-dioxide tetrahydrate, I, N,N′-di(p-tolyl)piperazine N,N′-dioxide tetrahydrate, II, and N,N′-di(p-chlorophenyl)piperazine N,N′-dioxide tetrahydrate, III, are described. Compound I crystallizes in space group [Formula: see text] with a = 7.778(1), b = 7.915(2), c = 8.919(2) Å, α = 106.25(2), β = 99.56(1), γ = 108.80(2)°, and Z = 1. Compound II crystallizes in space group [Formula: see text] with a = 6.558(1), b = 7.134(2), c = 11.610(3) Å; α = 73.23(2), β = 78.08(2), γ = 72.67(2)°, and Z = 1. Compound III crystallizes in space group P21/c with a = 9.159(3), b = 12.390(4), c = 8.339(4) Å, β = 97.38(3)°, and Z = 2. The structures of I–III were solved by the direct method and refined to R = 0.049 (1749 observed MoKα reflections), 0.055 (2651 observed reflections), and 0.035 (1827 observed reflections), respectively. In each case, the N,N′-dioxide molecule occupies a site of symmetry [Formula: see text]. The piperazine ring takes the chair form, with two N—O bonds oriented axially in a trans configuration. The structures are characterized by strong hydrogen bonding between the water molecules, as well as between the N-oxide groups and water molecules, giving rise to puckered layers composed of various combinations of edge-sharing four-membered, six-membered, ten-membered, and twelve-membered rings. The aryl rings, which protrude on both sides of each puckered layer, constitute hydrophobic regions separating the hydrophilic layers in the crystal packing.

Exoconformers ofN-(pyridin-2-yl)- andN-(pyridin-3-yl)norbornene-5,6-dicarboximide crystals

2015 ◽  
Vol 71 (3) ◽  
pp. 175-180
Author(s):  
Oscar F. Vazquez-Vuelvas ◽  
Julia V. Hernández-Madrigal ◽  
Armando Pineda-Contreras ◽  
Simón Hernández-Ortega ◽  
Reyna Reyes-Martínez ◽  
...  
Keyword(s):  
Double Bond ◽  
Single Crystal ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Compound I ◽  
Methylene Bridge ◽  
X Ray ◽  
Intermolecular Contacts ◽  
Independent Molecules ◽  
Compound Ii

Two isomeric pyridine-substituted norbornenedicarboximide derivatives, namelyN-(pyridin-2-yl)-exo-norbornene-5,6-dicarboximide, (I), andN-(pyridin-3-yl)-exo-norbornene-5,6-dicarboximide, (II), both C14H12N2O4, have been crystallized and their structures unequivocally determined by single-crystal X-ray diffraction. The molecules consist of norbornene moieties fused to a dicarboximide ring substituted at the N atom by either pyridin-2-yl or pyridin-3-yl in ananticonfiguration with respect to the double bond, thus affordingexoisomers. In both compounds, the asymmetric unit consists of two independent molecules (Z′ = 2). In compound (I), the pyridine rings of the two independent molecules adopt different conformations,i.e. synandanti, with respect to the methylene bridge. The intermolecular contacts of (I) are dominated by C—H...O interactions. In contrast, in compound (II), the pyridine rings of both molecules have ananticonformation and the two independent molecules are linked by carbonyl–carbonyl interactions, as well as by C—H...O and C—H...N contacts.

Zwitterionic and free forms of arylmethyl Meldrum's acids

2015 ◽  
Vol 71 (9) ◽  
pp. 752-758 ◽  
Author(s):  
Inese Mierina ◽  
Anatoly Mishnev ◽  
Mara Jure
Keyword(s):  
Crystal Packing ◽  
Building Blocks ◽  
Compound I ◽  
Molecular Conformations ◽  
X Ray ◽  
Methoxy Groups ◽  
Classical Hydrogen Bond ◽  
Meldrum's Acids ◽  
Compound Ii ◽  
Derivatives Of

C-Alkyl (including C-arylmethyl) derivatives of Meldrum's acids are attractive building blocks in organic synthesis, mainly due to the unusually high acidity of the resulting compounds. Three examples, namely 5-[4-(diethylamino)benzyl]-2,2-dimethyl-1,3-dioxane-4,6-dione, C17H23NO4, (I), 2,2-dimethyl-5-(2,4,6-trimethoxybenzyl)-1,3-dioxane-4,6-dione, C16H20O7, (II), and 5-(4-hydroxy-3,5-dimethoxybenzyl)-2,2-dimethyl-1,3-dioxane-4,6-dione, C15H18O7, (III), have been synthesized, characterized by NMR and IR spectroscopy, and studied by single-crystal X-ray structure analysis. The nature of the different substituents resulted in remarkable differences in both the molecular conformations and the crystal packing arrangements. The presence of a substituent with a basic centre in compound (I) leads to the formation of an inner salt accompanied by drastic changes in the conformation of the 1,3-dioxane-4,6-dione fragment. By virtue of strong N—H...O hydrogen bonds, the residues are assembled into infinite chains with the graph-set descriptorC(10). Compound (II) contains methoxy groups in both theortho- andpara-positions of the arylmethyl fragment. Because of the absence of classical hydrogen-bond donors in this structure, the crystal packing is controlled by van der Waals forces and weak C—H...O interactions. Compound (III) contains methoxy groups in bothmeta-positions and a hydroxy group in thepara-position. Supramolecular tetrameric synthons which comprise hydrogen-bonded dimers associated into tetramers through π–π interactions of overlapping benzene rings were observed.

Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Water Molecules ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

scholarly journals Interplay between Oxo and Fluoro in Vanadium Oxyfluorides for Centrosymmetric and Non-Centrosymmetric Structure Formation

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 603
Author(s):  
Prashanth Sandineni ◽  
Hooman Yaghoobnejad Asl ◽  
Weiguo Zhang ◽  
P. Shiv Halasyamani ◽  
Kartik Ghosh ◽  
...  
Keyword(s):  
Second Harmonic ◽  
Metastable Phase ◽  
Compound I ◽  
Hydrothermal Route ◽  
Prolonged Heating ◽  
Space Group ◽  
Lithium Vanadium Oxide ◽  
Compound Ii ◽  
Unambiguous Assignment ◽  
Centrosymmetric Structure

Herein, we report the syntheses of two lithium-vanadium oxide-fluoride compounds crystallized from the same reaction mixture through a time variation experiment. A low temperature hydrothermal route employing a viscous paste of V2O5, oxalic acid, LiF, and HF allowed the crystallization of one metastable phase initially, Li2VO0.55(H2O)0.45F5⋅2H2O (I), which on prolonged heating transforms to a chemically similar yet structurally different phase, Li3VOF5 (II). Compound I crystallizes in centrosymmetric space group, I2/a with a = 6.052(3), b = 7.928(4), c = 12.461(6) Å, and β = 103.99(2)°, while compound II crystallizes in a non-centrosymmetric (NCS) space group, Pna21 with a = 5.1173(2), b = 8.612(3), c = 9.346(3) Å. Synthesis of NCS crystals are highly sought after in solid-state chemistry for their second-harmonic-generation (SHG) response and compound II exhibits SHG activity albeit non-phase-matchable. In this article, we also describe their magnetic properties which helped in unambiguous assignment of mixed valency of V (+4/+5) for Li2VO0.55(H2O)0.45F5⋅2H2O (I) and +4 valency of V for Li3VOF5 (II).

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