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.

Darstellung, 11B-, 13C-, 29Si-NMR- und Schwingungsspektren von Trimethylsilylmethyl-hexahydro-closo-hexaborat, [B6H6(CH2Si(CH3)3)]- sowie Kristallstruktur von [P(C6H5)4][B6H6(CH2Si(CH3)3)] / Preparation, 11B, 13C, 29Si NMR and Vibrational Spectra of Trimethylsilylmethyl-hexahydro-clo-hexaborate, [B6H6(CH2Si(CH 3)3)]-and the Crystal Structure of [P(C6H5)4] [B6H6(CH2Si(CH3)3)]

1995 ◽  
Vol 50 (7) ◽  
pp. 1025-1029 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
29Si Nmr ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
X Ray ◽  
Quadrupole Coupling ◽  
Stretching Vibration ◽  
Ir And Raman ◽  
C Nmr

By reaction of [N(C4H9 )4]2 [B6H6] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B6H6 (CH2Si(CH3)3)]-, is formed. The crystal structure of [P(C6H5 )4][B6H6(CH2Si(CH3)3)] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P21/n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11B NMR spectrum reveals features of a mono hetero substituted octahedral B6 cage. The 13C NMR spectrum exhibits a quartet at +0.18 ppm with 1J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29Si NMR spectrum a decet at +2.25 ppm with 2J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm-1 in the IR and Raman spectrum.

Synthesis, Crystal Structure and Fluorescence Behavior of 2,6- Di(thiophen-2-yl)-benzo[1,2-d:4,5-d´]bisoxazole

2013 ◽  
Vol 68 (3) ◽  
pp. 239-244 ◽  
Author(s):  
Lan-Qin Chai ◽  
Yu-Li Zhang ◽  
Jun-Feng Tong ◽  
Gang Liu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Emission Spectroscopy ◽  
3D Structure ◽  
Monoclinic Space Group ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
C Nmr

An effective and clean new aerobic approach for the synthesis of 2,6-disubstituted benzobisoxazole by using a one-pot reaction of an organic aminoxyl radical as the catalyst is reported. 2,6- Di(thiophen-2-yl)-benzo[1,2-d : 4,5-d´]bisoxazole was synthesized with catalysis by the free radical 4-methoxy-TEMPO and characterized by 1H and 13C NMR spectroscopy, HRMS, as well as by elemental analysis, UV/Vis and emission spectroscopy. The crystal structure of the title compound has been determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group C2/c with a=12.531(1), b=3.8960(2), c = 28.733(2) Å, b = 100:760(1)°, Z = 4. Through intermolecular weak C-H· · ·O hydrogen bonding and p-p stacking interactions, a supramolecular 3D structure is formed.

Darstellung, 11B-, 13C-NMR-und Schwingungsspektren von Cyanomethylhexahydro-closo-Hexaborat(Hexaborat(1-), [B6H6(CH2CN)]– sowie Kristallstruktur von [P(C6H5)4][B6H6(CH2CN)] / Preparation, 11B, 13C NMR and Vibrational Spectra of Cyanomethylhexahydro-closohexaborate(1-), [B6H6(CH2CN)]- and the Crystal Structure of [P(C6H5)4][B6H6(CH2CN)]

1994 ◽  
Vol 49 (4) ◽  
pp. 471-476 ◽  
Author(s):  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
13C Nmr ◽  
Exchange Chromatography ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
Triclinic Space Group ◽  
X Ray ◽  
Diethylaminoethyl Cellulose ◽  
Ir And Raman ◽  
C Nmr

By reaction of [B6H6]2- with chloroacetonitrile in dichloromethane the cyanomethylhexahy-dro-closo-hexaborate(1-), [B6H6(CH2CN)]- is formed. The com pound has been separated from excess [B6H6]2- by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structure of [P(C6H5)4][B6H6(CH2CN)] has been determined by single crystal X-ray diffraction analysis; triclinic, space group P1 with a = 7.503(3), b = 12.0949(8), c = 14.6572(11) Å α = 79.399(6)°, β = 79.19(2)°, γ = 89.2(2)°. The 11B NMR spectrum is consistent with a mono hetero substituted octahedral B6 cage. In the 13C NMR spectrum of Cs2[B6H5(CH2CN)] a singlet at 131.9 ppm (CN) and a quartet at 2.97 ppm with 1J(C,B) = 54.7 Hz (CH2) are observed. The IR and Raman spectra exhibit a very strong CN stretching band at 2218 cm-1.

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.

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.

Synthesis and Structure of and Cation Distribution in the Zirconium Cluster Rb[(Zr6C)Cl15]

2008 ◽  
Vol 63 (5) ◽  
pp. 507-512 ◽  
Author(s):  
Henning W. Rohm ◽  
Martin Köckerling
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Cation Distribution ◽  
Type Structure ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coulombic Interactions ◽  
Cluster Network ◽  
Zirconium Cluster

Rb[(Zr6C)Cl15] was prepared by heating ZrCl4, Zr powder, RbCl and Al4C3 at 850 °C for 21 days. The crystal structure was determined by single crystal X-ray diffraction (space group Pmma, a = 18.484(3), b = 18.962(2), c = 9.708(1) Å, V = 2505.4(6) Å3, and Z = 4). Rb[(Zr6C)Cl15] crystallises in the Cs[Nb6Cl15]-type structure. It is built up from two interconnected types of cluster chains, one with linear Zr−Cla−a-Zr bridges, the other one with bent bridges. The rubidium cations are spread over three different sites within the cluster network which differs significantly from the cation distribution in the comparable potassium and caesium phases. The cation distribution can be rationalised considering the size of the cavities and the Coulombic interactions.

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.

Darstellung, 11B-NMR- und Schwingungsspektren von c/s-Monoethylmononitrotetrahydro- c/050-hexaborat(2-) sowie Kristallstruktur von cis (Ph4As)2[B6H4(C2H5)(NO2)] / Synthesis, 11B NMR and Vibrational Spectra of cis-Monoethylmononitrotetrahydroc-closo-hexaborate(2-) and Crystal Structure of cis-(Ph4As)2[B6 H4 (C2H5 )(NO2)]

1999 ◽  
Vol 54 (6) ◽  
pp. 772-776 ◽  
Author(s):  
C. Drewes ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Vibrational Spectra ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
Dichloromethane Solution ◽  
Triclinic Space Group ◽  
X Ray ◽  
11B Nmr ◽  
Ir And Raman

By electrochemical oxidation of (n-Bu4N)[B6H5Hfac(C2H5)] in the presence of nitrite ions and of the base DBU in dichloromethane solution cis-[B6H4(C2H5)(NO2)]2- is formed. X-ray diffraction analysis has been performed on a single crystal of cis-(Ph4 As)2[B6H4(C2H5)(NO2)] (triclinic, space group P1; a = 10.673(4). b = 10.907(4), c = 21.237(4) A, α = 80.789(4), β = 83.117(4), γ = 66.548(2)°, Z = 2). The 11B NMR spectrum is consistent with a disubstituted octahedral B6 cage with local Cs symmetry. The IR and Raman spectra exhibit characteristic CH3, CH2, NO2, BN, BH and B6 vibrations

scholarly journals Synthesis and Crystal Structure of C1-Symmetric 3,3′-Bi(1,1′-dinaphthyl-camphopyrazole)

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Jannis Barrera ◽  
Victoria A. Smolenski ◽  
Jerry P. Jasinski ◽  
Jesús Pastrán
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Stacking Interactions ◽  
Naphthalene Ring ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Group Form ◽  
C Nmr

The compound 3,3′-bi(1,1′-dinaphthyl-camphopyrazole) 1, C42H42O4, was obtained in good yield and structurally characterized by 1H and 13C NMR spectroscopy, elemental analysis, and X-ray diffraction. It consists of a 3,3′-bipyrazole group with each pyrazole ring containing a fused camphor group and a naphthalene ring bonded to the adjacent nitrogen atom in the ring. Both of the trimethyl, 5-membered rings of the fused camphor group form an envelope with the apex carbon atom as the flap in each case. In the crystal, weak π–π stacking interactions are observed between nearby 6-carbon rings of the two naphthalene rings linking the molecules into extended chains. Weak π–ring intermolecular interactions are also observed between naphthalene atoms and pyrazole rings from each of the groups helping to stabilize the crystal packing. No classical hydrogen interactions are formed.

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