Benzo-9-crown-3 ether: X-ray crystal structure, NMR studies in solution and the solid phase, and ab initio calculations of isotropic 13C chemical shifts using LORG with a D95V basis set

1993 ◽  
Vol 71 (12) ◽  
pp. 1983-1989 ◽  
Author(s):  
G.W. Buchanan ◽  
A.B. Driega ◽  
A. Moghimi ◽  
C. Bensimon ◽  
R.A. Kirby ◽  
...  
Keyword(s):  
Ab Initio ◽  
Solid Phase ◽  
Chemical Shifts ◽  
Basis Set ◽  
Length Variation ◽  
Nmr Studies ◽  
Nmr Spectrum ◽  
X Ray ◽  
Localized Orbital ◽  
C Nmr

Using the X-ray crystal geometry as input, the 13C NMR chemical shifts of benzo-9-crown-3 ether have been calculated via ab initio methods using a localized orbital local origin (LORG) approach. Reasonable agreement is found between the calculated values for an isolated molecule in the gas phase and those obtained in the 13C CPMAS NMR spectrum. Solid phase 13C spectra of the C7,10-d4 derivative confirm the existence of a 7.9 ppm shift difference between these sites in the solid, whereas in solution they are conformationally averaged to one resonance. The effects of C—H bond length variation on calculated 13C shifts have been explored.

Solid state stereochemistry of crown ethers: X-ray crystal structure and 13C NMR studies of the LiNCS complex of 1,4,7,11-tetraoxacyclotetradecane

2000 ◽  
Vol 78 (3) ◽  
pp. 316-321
Author(s):  
G W Buchanan ◽  
A B Driega ◽  
G PA Yap
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crown Ether ◽  
13C Nmr ◽  
Title Complex ◽  
Nmr Studies ◽  
Nmr Spectrum ◽  
X Ray ◽  
Large Amplitude Motion ◽  
C Nmr

The title complex is asymmetric in the crystal due to the spatial orientation of the NCS function. The space group has been determined to be P21 with a = 9.496(3), b = 8.736(3), c = 9.676(3) Å, β = 117.859(5)°, and Z = 2. The solid state 13C NMR spectrum is consistent with the lack of symmetry in the crystal and there is little evidence for large amplitude motion in the macrocycle as determined from the dipolar dephased spectrum.Key words: macrocyclic crown ether, lithium complex.

Electronic effects on crown ether conformation. X-ray crystal structure and 13C NMR study in solution and the solid phase of 4-nitrobenzo-9-crown-3 ether

1994 ◽  
Vol 72 (8) ◽  
pp. 1764-1768 ◽  
Author(s):  
G. W. Buchanan ◽  
A. B. Driega ◽  
A. Moghimi ◽  
C. Bensimon
Keyword(s):  
Crystal Structure ◽  
Crown Ether ◽  
13C Nmr ◽  
Solid Phase ◽  
Electronic Effects ◽  
Nmr Spectrum ◽  
X Ray ◽  
Nmr Study ◽  
C Nmr

The X-ray crystal structure of the title material has been determined and the results are compared to previous findings for benzo-9-crown-3 itself. The 13C NMR spectrum in solution has been unambiguously assigned using COSY and HETCOR methods. The solid phase 13C spectrum has been obtained and the 7, 10-d4 derivative has been examined to aid in spectral assignments.

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, X-ray structure determination, and formation of 3,4,5-trichloroguaiacol occurring in kraft pulp spent bleach liquors

1980 ◽  
Vol 58 (8) ◽  
pp. 815-822 ◽  
Author(s):  
K. Lindström ◽  
F. Österberg
Keyword(s):  
Reaction Mechanism ◽  
Melting Point ◽  
Structure Determination ◽  
Kraft Pulp ◽  
Chemical Shifts ◽  
X Ray ◽  
Nmr Chemical Shifts ◽  
Chemical Pulp ◽  
C Nmr

3,4,5-Trichloroguaiacol, which is formed during bleaching of chemical pulp and shown to bioaccumulate in fish, has been synthesized. The structure of the compound has been determined by means of X-ray analysis. The values of the 13C nmr chemical shifts and melting point differ from those previously reported. A reaction mechanism is suggested for the formation of 3,4,5- and 4,5,6-trichloroguaiacol.

Preparation, 1H and 13C NMR, and ab initio/IGLO study of mono-O-protonated deltic acid and theoretical investigation of di-, tri-, and tetra-O-protonated deltic acids

1999 ◽  
Vol 77 (5-6) ◽  
pp. 525-529 ◽  
Author(s):  
GK Surya Prakash ◽  
Golam Rasul ◽  
George A Olah ◽  
Ronghua Liu ◽  
Thomas T Tidwell
Keyword(s):  
Nmr Spectroscopy ◽  
Ab Initio ◽  
Theoretical Investigation ◽  
13C Nmr ◽  
Chemical Shifts ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Molar Solution ◽  
Protonated Species ◽  
C Nmr

The hitherto elusive mono-O-protonated deltic acid C3O3H3+ was prepared by protolysis of di-tert-butoxy deltate in FSO3H-SO2ClF and in FSO3H:SbF5 (Magic Acid; 1:1 molar solution) in SO2ClF as solvent at -78°C and was characterized by 1H and 13C NMR spectroscopy. The structure and NMR chemical shifts were also calculated by the ab initio/IGLO method. No NMR evidence was found for persistent di-O-protonated deltic acid under these conditions, although a limited equilibrium with the mono-O-protonated species can be involved. Di-, tri-, and tetra-O-protonated deltic acids were also studied by ab initio/IGLO method.Key words: protonated deltic acid, aromaticity, superacids, NMR spectroscopy, ab initio and IGLO calculations.

Synthesis, X-ray crystal structure, and solid-state 13C NMR study of tris(9-crown-3)triphenylene

2001 ◽  
Vol 79 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Gerald W Buchanan ◽  
Majid F Rastegar ◽  
Glenn PA Yap
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crown Ether ◽  
Chemical Shifts ◽  
Aromatic Rings ◽  
X Ray ◽  
Nmr Study ◽  
Group A ◽  
C Nmr ◽  
Solid State 13C Nmr

Benzo-9-crown-3 ether trimerizes in the presence of FeCl3 and aqueous H2SO4 to produce tris(9-crown-3)triphenylene in 25.4% yield. This compound crystallizes in the monoclinic P21/c space group: a = 13.759(2) Å, b = 13.318(2) Å, c = 13.399(2) Å, β = 96.883(2)°, with Z = 4. The three 9-crown-3 ether units of the trimer possess different geometries and there is substantial deviation from coplanarity in the three aromatic rings. 13C NMR chemical shifts in the solid state are consistent with this lack of symmetry and are discussed in terms of the X-ray crystal-structure data.Key words: crown ether, trimerization, stereochemistry.

3-Hexyne Complexes of M olybdenum(II) and Tungsten(II) Containing 2, 2 '-Bipyridine. X-Ray Crystal Structure of [MoI2(CO)(bipy)(η2-EtC2Et)]

2000 ◽  
Vol 55 (11) ◽  
pp. 1095-1098
Author(s):  
Mutlaq Al-Jahdali ◽  
Paul K. Baker ◽  
Michael B. Hursthouse ◽  
Simon J. Coles
Keyword(s):  
Crystal Structure ◽  
Carbon Monoxide ◽  
Room Temperature ◽  
Octahedral Geometry ◽  
Cationic Complex ◽  
Molybdenum Complex ◽  
Neutral Complex ◽  
Nmr Studies ◽  
X Ray ◽  
C Nmr

Reaction of [MI2(CO)(NCMe)(η2-EtC2Et)2] (M = Mo,W) with one equivalent of 2,2' -bipyridine (bipy) in CH2C12 at room temperature gives either the neutral complex, [MoI2(CO)(bipy)- (η2-EtC2Et)] (1) or the cationic complex, [WI(CO)(bipy)(η2-EtC2Et)2]I (2). The neutral molybdenum complex 1, has been crystallographically characterised, and has a pseudo-octahedral geometry with the iodo-ligand trans to the 3-hexyne, and with the bipy, carbon monoxide and other iodo-ligand occupying the equatorial face. 13C NMR studies show the 3-hexyne is donating four electrons to the molybdenum in 1.

Binap and MeO-Biphep complexes of Ru(II). Dicationic ligands as 6e donors. Unexpected cyclometallation in connection with P—C bond breaking

2001 ◽  
Vol 79 (5-6) ◽  
pp. 693-704
Author(s):  
Carolien J den Reijer ◽  
Pascal Dotta ◽  
Paul S Pregosin ◽  
Alberto Albinati
Keyword(s):  
Chemical Shifts ◽  
Bond Cleavage ◽  
Bond Breaking ◽  
Arene Complexes ◽  
Nmr Studies ◽  
Bonding Mode ◽  
C Nmr

A series of cationic and dicationic Ru-arene complexes with Binap (1a) and MeO-Biphep (1b) have been prepared. 13C NMR studies are shown to be useful in connection with recognising the 6e-bonding mode of 1a and 1b in the dications [Ru(1a or 1b)(η6-arene)](SbF6)2 (8,9). Reaction of 8,9 with: (a) (Bu4N)(Ph3SiF2) leads to a cyclometallated product which arises via P—C bond breaking and P—F bond making; (b) methanol provides a straightforward synthesis of the corresponding hydrides. 13C NMR p-cymene chemical shifts are reported.Key words: P—C bond cleavage, 6e donors, cyclometallation, hydrides, 13C NMR.

Solid state stereochemistry of crown ethers: X-ray crystal structure and 13C NMR studies of the LiNCS comple× of 1,4,7,11-tetrao×acyclotetradecane

2000 ◽  
Vol 78 (3) ◽  
pp. 316-321
Author(s):  
G.W. Buchanan ◽  
A.B. Driega ◽  
G.P.A. Yap
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crown Ethers ◽  
Nmr Studies ◽  
X Ray ◽  
C Nmr
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