scholarly journals Characterization and Structural Analysis of Genkwanin, a Natural Product from Callicarpa americana

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 491
Author(s):  
Gina Porras ◽  
John Bacsa ◽  
Huaqiao Tang ◽  
Cassandra L. Quave
Keyword(s):  
Natural Compound ◽  
Methanol Solution ◽  
Asymmetric Unit ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Independent Molecules ◽  
High Degree

The natural compound Genkwanin (systematic name: 5-hydroxy-2-(4-hydroxyphenyl)-7-methoxychromen-4-one) C16H12O5 (1) is a non-glycosylated flavonoid isolated from Callicarpa americana. Microcrystals of Genkwanin were prepared by slow evaporation of a methanol solution under low temperature conditions. The structure of 1 was determined based on spectroscopic analyses, one-dimensional NMR, HRESIMS and was confirmed by single-crystal X-ray diffraction. The crystals grow as very thin needles with an extremely high aspect ratio and with the long axis (along the y-axis) corresponding to the very short unit cell b-axis. There are two independent molecules in the asymmetric unit with two different conformations and modes of packing in the crystal. One molecule has a higher degree on non-planarity than the other. The short stacking distance and separation between the molecules implies a high degree of co-planarity consistent with a conjugated system. The crystal structure is non-centrosymmetric but achiral.

scholarly journals Syntheses, Characterization, and X-ray Crystal Structure of Binuclear Lanthanide Complexes Assembled with Schiff Base and Acetate

2021 ◽  
pp. 81-95
Author(s):  
Mbossé Ndiaye-Gueye ◽  
Amar Diop ◽  
Papa Aly Gaye ◽  
Ibrahima Elhadji Thiam ◽  
Farba Bouyagui Tamboura ◽  
...  
Keyword(s):  
Schiff Base ◽  
Intermolecular Hydrogen Bond ◽  
Methanol Solution ◽  
Tridentate Ligand ◽  
Water Molecules ◽  
Binuclear Complexes ◽  
Asymmetric Unit ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
X Ray

Herein we reported the binuclear complexes of the 1-(pyridin-2-yl)-2-(pyridin-2-ylmethylene)hydrazine ligand (HL) [Ln2(HL)2(CH3COO)6].n(H2O) (Ln = Y, Pr, Gd and Er). The binuclear complexes are characterized by IR and physical measurement. Spectroscopic evidence indicated that the Schiff base HL behave an N3 coordination tridentate ligand. The complexes are formulated as [{Ln(1-(pyridin-2-ylmethylidene-kN)-2-(pyridin-2-yl-kN)hydrazine-kN1)(h2-OOCH3)2}{h1:h2:m2-OOCH3}2{Ln(1-(pyridin-2-ylmethylidene-kN)-2-(pyridin-2-yl-kN)hydrazine-kN1))(h2-OOCH3)2}].n(H2O). The structure of the praseodymium complex was elucidated by X-ray diffraction analysis. Suitable crystals were grown by slow evaporation of methanol solution. The asymmetric unit of the compound contains two neutral ligand molecules, two Pr3+ ions, four acetate anions acting in h2-OOCH3 mode, two acetate anions acting in h1:h2:m2-OOCH3 mode, and three uncoordinated water molecules. The praseodymium atom is ten coordinated and the coordination sphere is best described as a distorted bicapped square antiprism. The PrIII···PrIII distance is 4.2777(6) Å and the bridging angle Pr—O—Pr and O—Pr—O are respectively 115.8(3)° and 64.2(3)°. The structure is consolidated by intra and intermolecular hydrogen bond.

Crystal structure of cis-Tetracarbonylbis(chloromercury)iron

1976 ◽  
Vol 29 (9) ◽  
pp. 1905 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
SB Wild
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Data ◽  
Title Compound ◽  
Direct Methods ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound has been determined by direct methods from X-ray diffraction data and refined by least squares to a residual of 0.071 for 2647 'observed' reflections. Crystals are monoclinic, C2/c, a = 36.81(1), b = 11.181(2), c = 20.369(5) �, β = 95.28(3)�, Z = 32. There are four independent molecules in the asymmetric unit, all with the cis disposition of ligands (<Fe-Hg), 2.498 �; <Hg-Fe-Hg), 80.9�); in one of the molecules one of the carbonyl sites is occupied by a more substantial moiety, possibly a result of partial occupancy of HgCl as a result of disorder or decomposition.

scholarly journals Crystal structures of 5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane cobalt(III) mono-phenylacetylide and bis-phenylacetylide

2018 ◽  
Vol 74 (4) ◽  
pp. 522-529 ◽  
Author(s):  
Benjamin M. Oxley ◽  
Brandon Mash ◽  
Matthias Zeller ◽  
Susannah Banziger ◽  
Tong Ren
Keyword(s):  
Crystal Structures ◽  
Symmetry Operator ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Weak Base ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Independent Molecules ◽  
Solvent Molecules ◽  
Occupancy Rates

Reported in this contribution are the synthesis and crystal structures of new mono- and bis-phenylacetylides based on CoIII(DMC) (DMC is 5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane). Chlorido(5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane)(phenylethynyl)cobalt(III) chloride–acetonitrile–methanol (1/1/1), [Co(C8H5)Cl(C12H28N4)]Cl·CH3CN·CH3OH, 1, and (5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane)bis(phenylethynyl)cobalt(III) trifluoromethanesulfonate–dichloromethane (2/1), [Co(C8H5)2(C12H28N4)]2(CF3SO3)2·CH2Cl2, 2, were prepared under weak-base conditions in satisfactory yields. Single-crystal X-ray diffraction studies revealed that both 1 and 2 adopt a pseudo-octahedral symmetry in which the Cl—Co—C angles of 1 and C—Co—C of 2 range from 177.7 (2) to 178.0 (2)° and from 177.67 (9) to 179.67 (9)°, respectively. In both structures, the CoIII metal center is coordinated in the equatorial plane by four N atoms, in which the N—Co—N angles range from 85.6 (3) to 94.4 (3)°. The structure of 1 features two crystallographically independent molecules in its triclinic cell (Z′ = 2), which are related to each other by pseudo-monoclinic symmetry. The crystal investigated was twinned by a symmetry operator of the approximate double-volume C-centered cell (180° rotation around [201] of the actual triclinic cell), with a refined twin ratio of 0.798 (3) to 0.202 (3). Both methanol solvent molecules in 1 are disordered, the major occupancy rates refined to 0.643 (16) and 0.357 (16). Compound 2 also contains two molecules in the asymmetric unit, together with two trifluoromethanesulfonate anions [of which one is disordered; occupancy values of 0.503 (16) and 0.497 (16)] and a disordered dichloromethane [occupancy values of 0.545 (12) and 0.455 (12)].

Crystal structure of trans-chlorobis(ethane-l,2-diamine)sulfitocobalt(III) monohydrate

1980 ◽  
Vol 33 (2) ◽  
pp. 419 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
JK Yandell
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound, [Co(en)2ClSO3],H2O (en = ethane-1,2-diamine), has been determined by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0.050 for 3252 'observed' reflections. Crystals are monoclinic, P21/c, a 9.862(4), b 15.897(8), c 16.936(7) Ǻ, β 117.44(4)°, Z 8. The two independent molecules in the asymmetric unit are pseudosymmetrically related. (Co-S) is 2.204 Ǻ, while (Co-Cl) is the longest six-coordinate cobalt(III)-chloride distance observed, being 2.377 Ǻ.

The synergistic co-operation of N—H...O=P hydrogen bonds and C—H...OX weak intermolecular interactions (X is =P or —C) in the (CH3O)2P(O)(NH–NHC6F5) amidophosphoester: a combined X-ray crystallographic and theoretical study

2019 ◽  
Vol 75 (10) ◽  
pp. 1424-1433
Author(s):  
Banafsheh Vahdani Alviri ◽  
Mehrdad Pourayoubi ◽  
Abolghasem Farhadipour ◽  
Manpreet Kaur ◽  
Jerry P. Jasinski
Keyword(s):  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Theoretical Study ◽  
Natural Bond Orbital ◽  
Asymmetric Unit ◽  
One Dimensional ◽  
X Ray ◽  
Weak Intermolecular Interactions ◽  
Dimensional Network ◽  
Independent Molecules

The asymmetric unit of O,O′-dimethyl [(2,3,4,5,6-pentafluorophenyl)hydrazinyl]phosphonate, C8H8F5N2O3P, is composed of two symmetry-independent molecules with significant differences in the orientations of the C6F5 and OMe groups. In the crystal structure, a one-dimensional assembly is mediated from classical N—H...O hydrogen bonds, which includes R 2 2(8), D(2) and some higher-order graph-set motifs. By also considering weak C—H...O=P and C—H...O—C intermolecular interactions, a two-dimensional network extends along the ab plane. The strengths of the hydrogen bonds were evaluated using quantum chemical calculations with the GAUSSIAN09 software package at the B3LYP/6-311G(d,p) level of theory. The LP(O) to σ*(NH) and σ*(CH) charge-transfer interactions were examined according to second-order perturbation theory in natural bond orbital (NBO) methodology. The hydrogen-bonded clusters of molecules, including N—H...O and C—H...O interactions, were constructed as input files for the calculations and the strengths of the hydrogen bonds are as follows: N—H...O [R 2 2(8)] > N—H...O [D(2)] > C—H...O. The decomposed fingerprint plots show that the contribution portions of the F...H/H...F contacts in both molecules are the largest.

The Crystal Structure of Indospicine Hydrochloride Hydrate

1992 ◽  
Vol 45 (6) ◽  
pp. 1021 ◽  
Author(s):  
MP Hegarty ◽  
CHL Kennard ◽  
KA Byriel ◽  
G Smith
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Amino Acid ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
A Cell ◽  
Independent Molecules ◽  
The One

The crystal structure of the hepatotoxic amino acid indospicine [L-6-amidino-2-aminohexanoic acid, (S)-2,7-diamino-7-iminoheptanoic acid], as its hydrochloride hydrate, has been determined by X-ray diffraction and refined to a residual R 0.036 for 845 observed reflections collected at 173 K. Crystals are orthorhombic, space group P 22121 with 8 molecules in a cell of dimensions a 5.1541(4), b 14.083(1), c 31.781(3) � . The structure is consistent with the one previously derived from chemical data but with the presence of a terminal amidinium ion and an α-amino acid zwitterion pair. The two independent molecules in the asymmetric unit are conformationally different and form a head-to-tail packing motif linked by NH(amidino)…O(carboxyl) hydrogenbonds (N…O,2.80, 2.85 � ). The structure also features extensive hydrogen bonding involving the water of solvation.

scholarly journals Synthesis, Structure, and Dielectric Properties of (3-Nitroanilinium) (18-Crown) (PF6)

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028
Author(s):  
Le Wang ◽  
Liu-lei Qin ◽  
Yang Liu ◽  
Peng Wang ◽  
Hui-ting Xu ◽  
...  
Keyword(s):  
Variable Temperature ◽  
Structural Phase ◽  
Dielectric Measurements ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
One Dimensional ◽  
X Ray ◽  
Potential Energy Calculations

(3-Nitroanilinium) (18-crown) (PF6) (1), which is an organic-inorganic hybrid containing one-dimensional chains of hydrogen-bonded supramolecular cations, was synthesized under slow evaporation conditions and subjected to differential scanning calorimetry, temperature-dependent dielectric measurements, and variable-temperature single-crystal X-ray diffraction analysis. These analyses revealed the occurrence of a reversible structural phase transition [P21/n P21/c] at 223 K and a dielectric anomaly, which, based on the results of structural analysis and potential energy calculations, was attributed to the synergistic effect between the pendulum-like motion of the nitro group in the supramolecular cation, (3-nitroanilinium)(18-crown), and the order-disorder motion of PF6− anions.

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.

A homochiral coordination polymer of cobalt(II) and L-serine

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Christelle N. Dzesse T. ◽  
Felicite Majoumo-Mbe ◽  
Emmanuel N. Nfor ◽  
Susan A. Bourne
Keyword(s):  
Coordination Polymer ◽  
Thermal Analyses ◽  
Divalent Metal ◽  
Helical Chain ◽  
Asymmetric Unit ◽  
Divalent Metal Ions ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Chelate Rings

A one-dimensional chiral cobalt(II) coordination polymer, namely, catena-poly[[[(S)-2-amino-3-hydroxypropanoato-κ2 N,O 1]cobalt(II)]-μ-(S)-2-amino-3-hydroxypropanoato-κ4 O 1,O 3:N,O 1′], [Co(C3H6NO3)2] n or Δ-[Co(L-Ser-κ2 N,O)2] n (L-Ser = L-serine) (1), has been synthesized and characterized using elemental and thermal analyses, IR spectroscopy and single-crystal and powder X-ray diffraction techniques. The asymmetric unit of 1 consists of two serine anions which are coordinated to a Co2+ ion to give three chelate rings. These extend the structure into a helical chain with pendant chelate rings which participate in interchain hydrogen bonding. The ability of 1 to undergo transmetallation was evaluated. Among a range of divalent metal ions, only copper(II) partially replaced cobalt(II).

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Sign in / Sign up

Export Citation Format

Share Document