Chemistry and crystal structure of leprolomin, a novel diphenyl ether from the lichen Psoroma leprolomum

1978 ◽  
Vol 31 (9) ◽  
pp. 2057 ◽  
Author(s):  
JA Elix ◽  
U Engkaninan ◽  
AJ Jones ◽  
CL Raston ◽  
MV Sargent ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Data ◽  
Diphenyl Ether ◽  
Structural Elucidation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lichen Metabolite

The isolation and structural elucidation of 3'-(2''-acetyl-3''-hydroxy- 5''-methoxy-4''-methylphenoxy)-2',4'-dihydroxy-6'-methoxy-5'- methylacetophenone (leprolomin) (12), an unusual lichen metabolite probably derived biogenetically by C-O phenolic coupling of two units of C-methylphloroacetophenone, is reported. Spectroscopic data on leprolomin and its derivatives allowed the structure to be limited to six possibilities; hence the crystal structure of leprolomin triacetate (15) was determined by X-ray diffraction.

The Structure of the Novel Lichen Xanthone Thiomelin and Its Cogenors

1987 ◽  
Vol 40 (7) ◽  
pp. 1169 ◽  
Author(s):  
JA Elix ◽  
KL Gaul ◽  
M Sterns ◽  
MW Binsamsudin
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Ring Opening ◽  
Spectroscopic Data ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lichen Metabolite

The structure determination of thiomelin (2,4-dichloro-1,8-dihydroxy-5-methoxy-6-methyl-9H-xanthen-9-one) (3), an unusual lichen metabolite probably derived biosynthetically by oxidative ring opening of a precursor anthraquinone, is reported. The crystal structure of thiomelin diacetate (4) was determined by X-ray diffraction, while that of the cogenors 8-O-methylthiomelin (5), 4-dechlorothiomelin (7), 4-dechloro-8- O- methylthiomelin (9), 2-dechloro-8- O- methylthiomelin (10) and 2,4-dichloro-l-hydroxy-7-methoxy-6,8-dimethyl-9H-xanthen-9-one (12) were deduced from spectroscopic data.

A New Bis-Tröger's Base: Synthesis, Spectroscopy, Crystal Structure and Isomerization

2006 ◽  
Vol 71 (9) ◽  
pp. 1278-1302 ◽  
Author(s):  
Martin Valík ◽  
Pavel Matějka ◽  
Eberhardt Herdtweck ◽  
Vladimír Král ◽  
Bohumil Dolensky
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Data ◽  
The Other ◽  
X Ray Diffraction ◽  
One Pot ◽  
Molecular Tweezers ◽  
X Ray ◽  
Troger's Base ◽  
Ir And Raman ◽  
C Nmr

A new bis-Tröger's base was prepared from a tetraamine precursor as a mixture of two diastereoisomers. One of the isomers has a chair-like geometry, and the other possesses a boat-like geometry, embodying molecular tweezers. A one-pot preparation of bis-TB isomers and their interconversion under acid conditions was also studied. Structures of both isomers were confirmed by single-crystal X-ray diffraction. Extensive spectroscopic data, including 1H and 13C NMR, IR and Raman spectra of the isomers, are given.

A threefold interpenetrating two-dimensional zinc(II) coordination polymer: synthesis, crystal structure and selective luminescence sensing properties

2019 ◽  
Vol 75 (7) ◽  
pp. 979-984 ◽  
Author(s):  
Chen-Dong Pan ◽  
Jun Wang ◽  
Ju-Qin Xu ◽  
Kang-Feng Zhang ◽  
Xiao-Wan Wang
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Aqueous Solution ◽  
Coordination Polymer ◽  
Diphenyl Ether ◽  
Biological Processes ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Framework

The Fe3+ ion is the most important element in environmental systems and plays a fundamental role in biological processes. Iron deficiency can result in diseases and highly selective and sensitive detection of trace Fe3+ has become a hot topic. A novel two-dimensional ZnII coordination framework, poly[[μ-4,4′-bis(2-methylimidazol-1-yl)diphenyl ether-κ2 N 3:N 3′](μ-4,4′-sulfonyldibenzoato-κ2 O:O′)zinc(II)], [Zn(C14H8O6S)(C20H18N4O)] n or [Zn(SDBA)(BMIOPE)] n , (I), where H2SDBA is 4,4′-sulfonyldibenzoic acid and BMIOPE is 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether, has been prepared and characterized by IR, elemental analysis, thermal analysis and X-ray diffraction analysis, the latter showing that the coordination polymer exhibits a threefold interpenetrating two-dimensional 44-sql network. In addition, it displays a highly selective and sensitive sensing for Fe3+ ions in aqueous solution.

scholarly journals New structural and spectroscopic data for eosphorite

1993 ◽  
Vol 57 (387) ◽  
pp. 329-336 ◽  
Author(s):  
M. A. Hoyos ◽  
T. Calderon ◽  
I. Vergara ◽  
J. Garcia-Solé
Keyword(s):  
Crystal Structure ◽  
Optical Absorption ◽  
Excitation Spectrum ◽  
Spectroscopic Data ◽  
Broad Band ◽  
Emission Lines ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

AbstractX-ray diffraction refinement of the crystal structure of eosphorite has been carried out with reference to the orthorhombic space group Cmca. The structure is similar to that previously described by Hanson (1960), but the standard deviations are improved. Optical absorption and photoluminescence have also been studied for this mineral. Two sharp emission lines, denoted as R1 and R2, superimposed to a broad band (630-750 nm) have been related to the presence of Cr3+ ions. The excitation spectrum of these emissions confirms that the absorption (excitation) bands centred at 431 nm and 585 are related to with 4A2 → 4T1 and 4A2 → 4T2 spin allowed transitions of this ion.

scholarly journals Redetermination of brackebuschite, Pb2Mn3+(VO4)2(OH)

2016 ◽  
Vol 72 (3) ◽  
pp. 293-296 ◽  
Author(s):  
Barbara Lafuente ◽  
Robert T. Downs
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Data ◽  
Structure Refinement ◽  
Common Vertex ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
Special Position ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Anisotropic Displacement Parameters

The crystal structure of brackebuschite, ideally Pb2Mn3+(VO4)2(OH) [dilead(II) manganese(III) vanadate(V) hydroxide], was redetermined based on single-crystal X-ray diffraction data of a natural sample from the type locality Sierra de Cordoba, Argentina. Improving on previous results, anisotropic displacement parameters for all non-H atoms were refined and the H atom located, obtaining a significant improvement of accuracy and an unambiguous hydrogen-bonding scheme. Brackebuschite belongs to the brackebuschite group of minerals with general formulaA2M(T1O4)(T2O4)(OH, H2O), withA= Pb2+, Ba, Ca, Sr;M= Cu2+, Zn, Fe2+, Fe3+, Mn3+, Al;T1 = As5+, P, V5+; andT2 = As5+, P, V5+, S6+. The crystal structure of brackebuschite is based on a cubic closest-packed array of O and Pb atoms with infinite chains of edge-sharing [Mn3+O6] octahedra located about inversion centres and decorated by two unique VO4tetrahedra (each located on a special position 2e, site symmetrym). One type of VO4tetrahedra is linked with the1∞[MnO4/2O2/1] chain by one common vertex, alternating with H atoms along the chain, while the other type of VO4tetrahedra link two adjacent octahedra by sharing two vertices with them and thereby participating in the formation of a three-membered Mn2V ring between the central atoms. The1∞[Mn3+(VO4)2OH] chains run parallel to [010] and are held together by two types of irregular [PbOx] polyhedra (x= 8, 11), both located on special position 2e(site symmetrym). The magnitude of the libration component of the O atoms of the1∞[Mn3+(VO4)2OH] chain increases linearly with the distance from the centerline of the chain, indicating a significant twisting to and fro of the chain along [010]. The hydroxy group bridges one Pb2+cation with two Mn3+cations and forms an almost linear hydrogen bond with a vanadate group of a neighbouring chain. The O...O distance of this interaction determined from the structure refinement agrees well with Raman spectroscopic data.

1,3-Digermapropan und 1,3,5-Trigermacyclohexan / 1,3-Digermapropane and 1,3,5-Trigermacyclohexane

1988 ◽  
Vol 43 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Johann Rott ◽  
Gabriele Reber ◽  
Gerhard Müller
Keyword(s):  
Crystal Structure ◽  
Mirror Symmetry ◽  
Spectroscopic Data ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Chair Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Germanium Powder

AbstractFrom the copper-catalyzed reaction of germanium powder with dichloromethane at 350 °C a mixture of alkylchlorogermanes is obtained, in which CH3GeCl3, CH2(GeCl3)2 (1) and (Cl2GeCH2)3 (2) are the major products. Treatment of 1 and 2 with LiAlH4 in di-n-butyl or diethylether, resp., affords the hydrides CH2(GeH3)2 (3) and cyclic (H2GeCH2)3 (4), the latter along with the heterocycle H2Ge(CH2GeH2)2 (5). Compounds 3-5 have been identified by analytical and spectroscopic data, and the crystal structure of 4 has been determined by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pmn21, with two molecules in the unit cell (a = 8.663(1), b = 7.783(1), c = 6.124(1) Å). The molecules, which are in a chair conformation, have crystallographic mirror symmetry with bond angles slightly larger than tetrahedral and Ge-C distances of 1.944(6), 1.953(3) and 1.955(4) Å. The compounds show potential as substrates for plasma-enhanced chemical vapour deposition (PE-CVD) of amorphous germanium carbon alloys (a-Ge, C:H).

Kristallstruktur und schwingungsspektroskopische Daten von Silbercyanamid / Crystal Structure and Spectroscopic Data of Silver Cyanamide

2000 ◽  
Vol 55 (5) ◽  
pp. 383-385 ◽  
Author(s):  
Michael Becker ◽  
Jürgen Nuss ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Aqueous Solutions ◽  
Single Crystal ◽  
Silver Nitrate ◽  
Title Compound ◽  
Spectroscopic Data ◽  
Crystalline Solid ◽  
X Ray Diffraction ◽  
X Ray

Ag2CN2 precipitates on mixing aqueous solutions of H2CN2 and silver nitrate as a yellow crystalline solid. The title compound was characterised by single crystal X-ray diffraction and IR-spectroscopy (monoclinic, P21/c (No. 14), a = 7.315(1), b = 6.010(1), c = 6.684(1) Å; β = 102.29( 1)°; Z = 4). The anion is slightly bent (177.1 (5)°) and exhibits two significantly different bond lengths (C-N(l): 1.194(6), C-N(2): 1.266(5) Å).

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

Crystal Forms of Semisynthetic Ergot Alkaloid Terguride

2002 ◽  
Vol 67 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Ivana Císařová ◽  
Ladislav Cvak ◽  
Alexandr Jegorov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ergot Alkaloid ◽  
Simplified Model ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
X Ray Diffraction ◽  
Torsion Angles ◽  
Crystal Forms ◽  
X Ray ◽  
Independent Molecules

Two new structures of semisynthetic ergot alkaloid terguride created by unusual number of symmetry-independent molecules were determined by X-ray diffraction methods at 150 K. Form A (monoclinic, P212121, Z = 12) contains three symmetry-independent terguride molecules and two molecules of water in the asymmetric part of the unit cell. The form CA (monoclinic, P21, Z = 8) is an anhydrate remarkable by the presence of four symmetry-independent molecules in the crystal structure. Conformations of twelve symmetry-independent molecules that were found in four already described terguride structures are compared with torsion angles obtained by ab initio quantum-mechanical calculations for the simplified model of N-cyclohexyl-N'-diethylurea.

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