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.

Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands

2020 ◽  
Vol 75 (9-10) ◽  
pp. 851-857
Author(s):  
Chong Chen ◽  
Fule Wu ◽  
Jiao Ji ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Structural Characterization ◽  
Room Temperature ◽  
Molecular Structures ◽  
Cationic Complex ◽  
Neutral Complex ◽  
Ancillary Ligands ◽  
X Ray ◽  
X Ray Crystallography

AbstractTreatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.

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.

scholarly journals X-ray crystal structure determination and NMR solution studies of 3′,3″5′,5″-tetrabromophenolphthalein ethyl ester

1991 ◽  
Vol 69 (8) ◽  
pp. 1298-1305 ◽  
Author(s):  
Antony C. Chiverton ◽  
Suzanne Fortier ◽  
John W. Bovenkamp ◽  
D. Thoraval ◽  
G. W. Buchanan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ethyl Ester ◽  
Room Temperature ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solution Studies ◽  
Central Carbon ◽  
Dark Blue ◽  
C Nmr

The crystal structure of 3′,3″,5′,5″-tetrabromophenolphthalein ethyl ester (TBPE) has been determined by X-ray diffraction at room temperature. This compound crystallizes in space group [Formula: see text], with a = 12.361(4), b = 12.533(4), c = 9.986(2) Å, α = 99.57(3), β = 112.76(2), γ = 100.73(3) °, and Z = 2. The structure was solved by direct methods and refined by full-matrix least-squares calculations to a residual of 0.034 for 1862 observed reflections. TBPE is propeller shaped about the central carbon and crstallizes with one molecule of benzene solvent per asymmetric unit. In 1:1 CD2Cl2:CDCl3 solution complete 1H and 13C NMR signal assignments have been made via 1H1H COSY and 1H13C HETCOR experiments. The quinoidal and phenolic integrities are retained on the NMR timescale. By contrast for an acetone-d6 solution only 14 13C resonances are found and the colour of the solution changed from green to dark blue. These changes in acetone solution are attributed to the presence of a trace of base which induces the loss of the phenolic proton of TBPE and the existence of resonance forms which render the phenolic and quinoidal rings equivalent. Key words: crystal structure, NMR, 3′3″5′5″-tetrabromophenolphthalein ethyl ester.

Formation of a trimeric chloroguaiacol quinone in the preparation of tetrachloroguaiacol and crystal structure of its tetramethoxy derivative

1986 ◽  
Vol 64 (5) ◽  
pp. 950-954
Author(s):  
Nick Burlinson ◽  
Steven J. Rettig ◽  
James Trotter ◽  
Bruce McKague
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Conformational Isomerism ◽  
Nmr Studies ◽  
Full Matrix ◽  
X Ray ◽  
Expected Values ◽  
Intermolecular Distances ◽  
C Nmr

A by-product formed in the preparation of tetrachloroguaiacol is shown to be a trimeric quinone. Derivatization of the quinone to a crystalline tetramethoxy derivative allowed X-ray determination of its crystal structure as 3,6-dichloro-4,5-dimethoxy-1,2-bis(2′-methoxy-3′,4′,5′,6′-tetrachlorophenoxy)benzene, 4. Rarely observed long range JCH coupling between ring carbons and methoxyl hydrogens as well as conformational isomerism were observed in 1H and 13C nmr studies of 4. Crystals of 4 are triclinic, a = 12.562 (1), b = 12.708(1), c = 9.223(1) Å, α = 96.93(1), β = 97.478(7), γ = 101.285(8)°, Z = 2, space group[Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.056 and Rw = 0.056 for 2946 reflections with I ≥ 1.5σ(I). The molecule contains a central six-membered dichloro-tetraoxo substituted aromatic ring, linked via oxygen bridges to two identical tetrachloro-dioxo substituted rings; intramolecular steric overcrowding causes significant deviations from a symmetrical conformation. Bond lengths, angles, and intermolecular distances are generally close to expected values.

Structural and spectral study of coordination of 4,4′-dimethoxy-2,2′-bipyridine toward Zn(II) and Cd(II) containing thiocyanato or azido ligands

2016 ◽  
Vol 71 (9) ◽  
pp. 959-965 ◽  
Author(s):  
Farzin Marandi ◽  
Keyvan Moeini ◽  
Hadi Amiri Rudbari
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Distorted Octahedral ◽  
Ft Ir ◽  
New Compounds ◽  
C Nmr

AbstractThree new compounds of zinc(II) and cadmium(II) with the ligand 4,4′-dimethoxy-2,2′-bipyridine (4,4′-dmo-2,2′-bpy), including cis-[Zn(4,4′-dmo-2,2′-bpy)2(SCN)2] (1), cis-[Cd(4,4′-dmo-2,2′-bpy)2(SCN)2] (2), and [Cd3(4,4′-dmo-2,2′-bpy)3(N3)5(OAc)]n (3), have been obtained as white single crystals by the branched tube method and characterized by elemental analysis, FT-IR and 1H, 13C NMR spectroscopy, and X-ray crystallography. Single-crystal structure analyses of the isostructural complexes 1 and 2 showed distorted octahedral geometry for zinc(II) and cadmium(II) with ZnN6 and CdN6 environments. Complex 3 reveals a rare coordination polymer containing octahedrally coordinated cadmium(II) expanding to chains by two different bridging modes, including Cd‒O‒C‒O‒Cd and Cd‒N‒Cd.

scholarly journals Novel O-C-C-O and C-O-C-C stereochemistry in crown ether analogs. X-ray crystal structure and NMR studies of dibenzo-20-crown-6

1995 ◽  
Vol 73 (1) ◽  
pp. 100-105 ◽  
Author(s):  
G.W. Buchanan ◽  
A. Moghimi ◽  
C. Bensimon
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crown Ether ◽  
Crown Ethers ◽  
Nmr Studies ◽  
Trans Conformation ◽  
Torsion Angles ◽  
X Ray ◽  
Solid State Conformation ◽  
C Nmr

The X-ray crystal structure of the title material indicates that the molecule possesses a pseudo-centre of inversion. A pair of O-C-C-O bonds have a trans conformation in contrast to normal gauche stereochemistry for such units in crown ethers. For the C-O-C-C networks, which are normally transoid in crown ethers, all four such units involving methylene carbons of the 20-membered ring exhibit unusual geometries. Two units possess gauche conformations and the other two have torsion angles near 120°. Solution 1H and 13C NMR spectra have been recorded as a function of temperature and 13C solid state spectra are included. Keywords: crown ether, solid state conformation.

Ferrocenyl-penta-(β-naphthyl)benzene — Synthesis, structure, and dynamic behaviour

2003 ◽  
Vol 81 (11) ◽  
pp. 1180-1186 ◽  
Author(s):  
Laura E Harrington ◽  
James F Britten ◽  
Michael J McGlinchey
Keyword(s):  
Crystal Structure ◽  
Carbon Monoxide ◽  
Low Temperature ◽  
Dynamic Behaviour ◽  
Variable Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Nmr Studies ◽  
X Ray ◽  
Diels Alder Reaction

3-Ferrocenyl-2,4,5-tri-(β-naphthyl)cyclopentadienone undergoes a Diels–Alder reaction with di-(β-naphthyl) acetylene to yield, after elimination of carbon monoxide, ferrocenyl-penta-(β-naphthyl)benzene (4). 1H and 13C variable-temperature NMR studies on 4 reveal the existence of multiple diastereoisomers at low temperature. These data are interpreted in terms of slowed rotation of the naphthyl groups, and are supported by the X-ray crystal structure of 4, which exhibits disorder at three of the naphthyl sites.Key words: sterically crowded molecules, hindered rotations, crystallography, NMR.

A topochemical rearrangement with multiple inversions of configuration

2001 ◽  
Vol 79 (8) ◽  
pp. 1272-1277 ◽  
Author(s):  
Saul Wolfe ◽  
Yih-Huang Hsieh ◽  
Raymond J Batchelor ◽  
Frederick WB Einstein ◽  
Ian D Gay
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Room Temperature ◽  
The Other ◽  
X Ray ◽  
Controlled Processes ◽  
X Ray Crystallography ◽  
Intramolecular Process ◽  
C Nmr ◽  
The Ideal

Crystalline 2-benzyloxypyridine-1-oxide rearranges slowly at room temperature to crystalline 1-benzyloxy-2-pyridone. No intermediates are detected when the process is followed by solid-state 13C NMR. The crystal structure of the pyridine-1-oxide strongly suggests that a topochemically controlled intramolecular process, in which the benzyl group migrates with retention of configuration, is not feasible. On the other hand, although somewhat disfavoured by initial solid-state O···C···O angles significantly less than the ideal 180°, intermolecular topochemically controlled processes can be envisaged that lead, with multiple inversions of configuration, either to net retention of configuration or to net inversion of configuration in the benzyl group. In contrast to the 50–80% inversion observed in solution, in the solid state only inversion is observed experimentally when chirally labelled α-deuteriobenzyloxypyridine-1-oxide is allowed to rearrange.Key words: X-ray crystallography, solid-state 13C NMR, benzyl-α-D-alcohol, 2-benzyloxypyridine-1-oxide, 1-benzyloxy-2-pyridone.

Tetraalkylammonium Tetrachlorothallates (III); X-Ray, 35Cl-NQR, and 1H-NMR Studies

1991 ◽  
Vol 46 (9) ◽  
pp. 777-784 ◽  
Author(s):  
Marco Lenck ◽  
Shi-qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Ii ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Nmr Studies ◽  
X Ray ◽  
H Nmr ◽  
35Cl Nqr ◽  
Low Temperature Phase

AbstractThe crystal structure of (CH3)4NTlCl4 and (C2H5)4NTlCl4 was determined at room temperature by single crystal technique. (CH3)4NTlCl4: D2h17-Cmmm; Z = 2; a = 913.2pm, b = 894.6 pm, c = 752.5 pm; (C2H5)4NTlCl4: C6v4-P63mc; Z = 2; a = 827.9 pm, c = 1329.8 pm. (C2H5)4NTlCl4 is isomorphous with (C2H5)4NInCl4. The compounds undergoe a phase transition at 239 K and 222 K, respectively. For both compounds no35 Cl NQR signal was observable in the high temperature phase I due to the dynamics of the anion. The 35 Cl NQR was studied in the low temperature phase II of both compounds as a function of temperature. (CH3)4NTlCl4 shows a two line, (C2H5)4NTlCl4 a four line spectrum. The possible phase II structures and the dynamics of the cation, studied by 1H-NMR, are discussed

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