scholarly journals Unusual Seven Coordination of Oxovanadium(V) Oximato Complex: Synthesis and X-Ray Crystal Structure

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Shadia A. Elsayed ◽  
Ahmed M. El-Hendawy ◽  
Mohamed I. El-Mahdy
Keyword(s):  
Crystal Structure ◽  
Physicochemical Properties ◽  
Intermolecular Interactions ◽  
Supramolecular Structure ◽  
Membered Ring ◽  
The Other ◽  
Axial Position ◽  
X Ray ◽  
Imine Nitrogen ◽  
Coordination Sites

The new oxovanadium(V) complex, [VO(acac)(dametsc)] (1) (acac = acetylacetonate (-1), H2dametsc = diacetylmonoxime-4-ethylthiosemicarbazone), has been prepared and characterized by studying its physicochemical properties. The X-ray crystal structure of the complex (1) has been determined and showed the presence of vanadium(V) atom in a unique heptacoordination state with distorted pentagonal bipyramidal geometry. The oximato ligand in the pentagonal plane is bonded to the central vanadium atom in dihapto (η2= N,O) manner with the formation of three membered ring, while the other three coordination sites in the plane are occupied by hydrazinic imine nitrogen, thiolate sulfur, and one of the acac oxygen atoms. The axial position sites are defined by the other acac oxygen and the trans oxo-atom. The supramolecular structure of the complex is exclusively constructed by intermolecular interactions, N–H⋯O and C–H⋯O.

scholarly journals Molekül- und Kristallstruktur des 1.5-Dichlor-3.7-bis(trifluormethyl)-4.8-bis(2′.6′-dimethylphenyl)-2.6.9-trioxa- 4.8-diaza-1.5-diborabicyclo [3.3.1] nonadiens / Molecular and Crystal Structure of 1,5-Dichloro-3,7-bis(trifluoromethyl)-4,8-bis(2′,6′-dimethylphenyl)-2,6,9-trioxa-4,8-diaza- 1,5-diborabicyclo[3,3,1 ]nonadiene

1980 ◽  
Vol 35 (12) ◽  
pp. 1499-1502 ◽  
Author(s):  
William Clegg ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick ◽  
Walter Maringgele ◽  
Anton Meller
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Membered Ring ◽  
The Other ◽  
Molecular And Crystal Structure ◽  
Compound A ◽  
Space Group ◽  
X Ray

The structure of the title compound (a = 1185.4, b = 1197.7, c = 1764.8 pm, β = 73.96°, space group P21/c) has been determined from X-ray diffractometer data. The molecule is structurally analogous to the tetraborate ion [B4O7]2-. The eight-membered ring is folded by 104° about the B - B vector. The boron atoms are more strongly bonded to the bridging oxygen [B-O(B) 139 pm] than to the other atoms [B-O(C) 155 pm, B-N 160 pm, B-Cl 182 pm].

Reactions of PO(NCS)3 with 4-Hydroxy-1,3-dioxanes. Crystal Structure of rel-(2S,4R,5S,6S)-2,6-Diethyl-5-methyl-4-(N'-benzylthioureido)-1,3-dioxane

1992 ◽  
Vol 57 (6) ◽  
pp. 1299-1313 ◽  
Author(s):  
Juraj Bernát ◽  
Ladislav Kniežo ◽  
Gabriela Birošová ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Crystalline Form ◽  
The Other ◽  
Axial Position ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Alkyl Groups

Substituted 4-hydroxy-1,3-dioxanes II react rapidly with PO(NCS)3 to give 4-isothiocyanato-1,3-dioxanes III. The 1H NMR spectra showed that in the isothiocyanate IIIa the predominant stereoisomer has its NCS group in axial position. The addition of benzylamine to the isothiocyanates IIIa and IIIb gave uniform thioureas IVa and IVb with equatorial alkyl groups at 2 and 6 positions and axial thioureido group at 4 position. On the other hand, the isothiocyanate IIIc reacts with benzylamine to give a mixture of three stereoisomeric thioureas V,VI, and VIII. The structure of VI was proved by means of X-ray diffraction analysis; in crystalline form the molecules of VI are present as H-bonded dimers (N-H...O).

Zur Chemie der 1,3,5-Triaza-2-phosphorinan-4,6-dione. Teil IX. Umsetzungen einiger 1,3,5-Triorgano-1,3,5-triaza-2λ3-phosphorinan-4,6-dione mit Hexafluoraceton / Chemistry of the 1,3,5-Triaza-2-phosphorinan-4,6-diones. Part IX. Reaction of some 1,3,5-Triorgano-1,3,5-triaza-2λ3-phosphorinan-4,6-diones with Hexafluoroacetone

1995 ◽  
Vol 50 (12) ◽  
pp. 1785-1790 ◽  
Author(s):  
Ion Neda ◽  
Michael Farkens ◽  
Axel K. Fischer ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
Phosphorus Atom ◽  
Mass Spectra ◽  
Membered Ring ◽  
The Other ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Phosphoryl Compound ◽  
Spirocyclic Compounds

The reactions of 2-(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2λ3-phosphorinan- 4,6-dione (1), 2-bis(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2A3-phosphorinan- 4,6-dione (2), 2-methoxy-1,3,5-trimethyl-1,3,5-triaza-2λ3-phosphorinan-4,6-dione (3) and 2-trimethylsiloxy-1,3,5-trimethyl-1,3,5-triaza-2λ3-phosphorinan-4,6-dione (5) with hexafluoracetone are described. In the case of 2 and 3 the reaction furnished the spirocyclic compounds 7 and 8. 2-Bis(2-chloroethyl)amino-1,3,5-triphenyl-1,3,5-triaza-2λ3-phosphorinan- 4,6-dione (4) did not react. In the case of 1 and 5 rearrangement reactions took place; the (2-chloroethyl)amino substituent of 1 reacted with one of two equivalents of hexafluoroacetone with formation of the spirocyclic phosphorane 6. The reaction of 5 with tetrabromoorthobenzoquinone gave the phosphoryl compound 9. Compounds 6 - 8 were characterized via their 1H-, 13C-, 19F- and 31P-NMR and mass spectra, compound 9 via its 1H-, 13C- and 31P-NMR and mass spectra. An X-ray crystal structure determination of 8 was conducted; in the six-membered ring the phosphorus atom lies 73 pm out of the plane of the other atoms, and displays trigonal bipyramidal coordination.

scholarly journals Pseudo-polymorphism of Halogen Substituted Tetraaza[14]annulene Complexes

2014 ◽  
Vol 70 (a1) ◽  
pp. C1004-C1004
Author(s):  
Shuhei Ichimura ◽  
Masahiro Saeki ◽  
Yoshinori Tamaki ◽  
Kazuo Miyamura
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Single Crystals ◽  
Membered Ring ◽  
Space Group ◽  
X Ray ◽  
Coordination Sites ◽  
The Difference

6,8,15,17-tetramethyldibenzo-5,9,14,18-tetraazacyclotetradecinatonickel (II) (tmtaa) bears strain within its 14-membered ring and is known to adopt saddle-shaped structure. As a consequence, tmtaa has an asymmetric apical coordination sites at both sides of the saddle. Our previous study revealed that the chlorine substituted complex, [Ni(tmtaa-4Cl)] shown in Figure (X = Cl), exhibited pseudo-polymorphism with dichloromethane and chloroform. This behaviour is due to the good affinity between halogen substituents and halomethane solvent. In this study, we grew single crystals of [Ni(tmtaa-4Br)] using various halomethane solvent as crystallization solvents and elucidated the role of the solvents related to the generation of pseudo-polymorprhism. We have succeeded in obtaining two kinds of single crystals 1 and 2 from the same vial container using bromoform. From X-ray structural analysis, 1 and 2 formed twist dimer as with previous report, and are found to include bromoform in their crystal structure. Note that these complexes adopted more distorted saddle-shaped structure than normal tmtaa complexes. The Ni-N4 planes were not planar. The difference of 1 and 2 was the degree of distortion around Ni-N4 plane, and 1 was more distorted than 2. The space group of these complexes were Aba2 and C2/c respectively. The interactions that led to the difference in packing of dimers were CH...π interaction in 1 and π...π interaction in 2.

scholarly journals Crystal structure of 3-benzyl-2-[(E)-2-(furan-2-yl)ethenyl]-2,3-dihydroquinazolin-4(1H)-one and 3-benzyl-2-[(E)-2-(thiophen-2-yl)ethenyl]-2,3-dihydroquinazolin-4(1H)-one from synchrotron X-ray diffraction

2018 ◽  
Vol 74 (1) ◽  
pp. 10-14
Author(s):  
Flavien A. A. Toze ◽  
Vladimir P. Zaytsev ◽  
Lala V. Chervyakova ◽  
Elisaveta A. Kvyatkovskaya ◽  
Pavel V. Dorovatovskii ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Axial Position ◽  
Isatoic Anhydride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Angles ◽  
Pyramidal Geometry ◽  
Three Component Reaction ◽  
Racemic Crystals

The chiral title compounds, C21H18N2O2, (I), and C21H18N2OS, (II) – products of the three-component reaction between benzylamine, isatoic anhydride and furyl- or thienyl-acrolein – are isostructural and form isomorphous racemic crystals. The tetrahydropyrimidine ring in (I) and (II) adopts a sofa conformation. The amino N atom has a trigonal–pyramidal geometry [sum of the bond angles is 347.0° for both (I) and (II)], whereas the amido N atom is flat [sum of the bond angles is 359.3° for both (I) and (II)]. The furyl- and thienylethenyl substituents in (I) and (II) are planar and the conformation about the bridging C=C bond isE. These bulky fragments occupy the axial position at the quaternary C atom of the tetrahydropyrimidine ring, apparently, due to steric reasons. In the crystals, molecules of (I) and (II) form hydrogen-bonded helicoidal chains propagating along [010] by strong intermolecular N—H...O hydrogen bonds.

PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

2001 ◽  
Vol 15 (18) ◽  
pp. 2491-2497 ◽  
Author(s):  
J. L. ZHU ◽  
L. C. CHEN ◽  
R. C. YU ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
The Other ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

Molecular tapes in the structure of isoguaninium chloride

2017 ◽  
Vol 74 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Urszula Anna Budniak ◽  
Paulina Maria Dominiak
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Charge Density ◽  
Interaction Energy ◽  
Electrostatic Interaction ◽  
Electrostatic Interactions ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure

Isoguanine, an analogue of guanine, is of intrinsic interest as a noncanonical nucleobase. The crystal structure of isoguaninium chloride (systematic name: 6-amino-2-oxo-1H,7H-purin-3-ium chloride), C5H6N5O+·Cl−, has been determined by single-crystal X-ray diffraction. Structure analysis was supported by electrostatic interaction energy (E es) calculations based on charge density reconstructed with the UBDB databank. In the structure, two kinds of molecular tapes are observed, one parallel to (010) and the other parallel to (50\overline{4}). The tapes are formed by dimers of isoguaninium cations interacting with chloride anions. E es analysis indicates that cations in one kind of tape are oriented so as to minimize repulsive electrostatic interactions.

Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol

2004 ◽  
Vol 219 (10) ◽  
Author(s):  
Swastik Mondal ◽  
Monika Mukherjee ◽  
Arnab Roy ◽  
Debabrata Mukherjee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Data ◽  
Molecular Conformation ◽  
Membered Ring ◽  
Methyl Groups ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures

Abstract(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R

scholarly journals Di-μ-chlorido-bis{[2-(di-tert-butylphosphanyl)biphenyl-3-yl-κ2C3,P]palladium(II)} dichloromethane disolvate

2013 ◽  
Vol 69 (2) ◽  
pp. m86-m86 ◽  
Author(s):  
Cedric W. Holzapfel ◽  
Bernard Omondi
Keyword(s):  
Palladium Complex ◽  
Solvent Molecule ◽  
Membered Ring ◽  
The Other ◽  
Coordination Geometry ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Coordination Sites ◽  
Square Planar ◽  
Cl Atoms

The asymmetric unit of the title compound, [Pd2Cl2(C20H26P)2]·2CH2Cl2, contains one half-molecule of the palladium complex and a dichloromethane solvent molecule. In the complex, two PdIIatoms are bridged by two Cl atoms, with the other two coordination sites occupied by a C atom of the biphenyl system and a P atom, resulting in a distorted square-planar coordination geometry of the PdIIatom and a cyclometallated four-membered ring. The Pd2Cl2unit is located about an inversion center. The planes of the rings of the biphenyl system make a dihedral angle of 66.36 (11)°.

Crystal Structure of Calcium Picrate Pentahydrate: A New Eight-Coordinate Stereochemistry for [M(bidentate)2(unidentate)4]

1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Single Crystal ◽  
Title Compound ◽  
Lattice Site ◽  
The Other ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Triangular Face ◽  
X Ray

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.

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