Reactions of 7-azaindole with niobium and tantalum pentachlorides and coupling to the azaindolyl-azaindolium cation

1994 ◽  
Vol 72 (7) ◽  
pp. 1675-1683 ◽  
Author(s):  
Jacques Poitras ◽  
André L. Beauchamp
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Infrared Spectra ◽  
Oxidative Coupling ◽  
Room Temperature ◽  
H Nmr ◽  
Counter Ion ◽  
Distorted Octahedral ◽  
Complex Salts

The reaction of NbCl5 and TaCl5 with 7-azaindole (Haza) at room temperature in benzene or dichloromethane yielded MCl5(Haza) addition compounds. Under more severe conditions, the same compound was obtained with TaCl5. For NbCl5, some reduction to Nb(IV) was observed and NbCl5(Haza), NbCl4(Haza)2, and the (H2aza)+ ion were identified in the reaction mixture by infrared spectroscopy. Oxidative coupling of two azaindole units via N7—C6 also took place during the reaction, since the 7-(azaindol-6-yl)azaindolium cation was found as counter-ion in the crystal structures of two complex salts. In the crystals of (H2aza-aza)[NbOCl4(Haza)]•0.5CH2Cl2([Formula: see text]a = 7.255 Å, b = 12.412 Å, c = 14.277 Å, α = 89.03°, β = 85.60°, γ = 76.66°, Z = 2, R = 0.062), the anion is the roughly octahedral [NbOCl4(azaindole)]− species containing a neutral N7-coordinated azaindole trans to the Nb=O bond. The [NbOCl5]2− salt ([Formula: see text]a = 7.527 Å, b = 10.168 Å, c = 10.467 Å, α = 66.41°, β = 84.07°, γ = 85.51°, Z = 1, R = 0.037) contains the distorted octahedral [NbOCl5]2− ion disordered over two orientations. The infrared spectra suggest monomeric octahedral structures for the MCl5(Haza) and NbCl4(Haza)2 complexes. 1H NMR spectroscopy shows that NbCl5(Haza) is not dissociated in CD2Cl2.

Das dynamische Verhalten des 1-Methyl-1-benzothiepinium-Ringsystems/The Dynamic Behaviour of the 1-Methyl-1-benzothiepinium Ring System

1981 ◽  
Vol 36 (8) ◽  
pp. 974-977 ◽  
Author(s):  
Hans Hofmann ◽  
Franz Dickert
Keyword(s):  
Nmr Spectroscopy ◽  
Room Temperature ◽  
Dynamic Behaviour ◽  
Ring System ◽  
Membered Ring ◽  
Ring Inversion ◽  
Methyl Group ◽  
H Nmr ◽  
Pyramidal Inversion ◽  
Mutual Conversion

Abstract By 1H NMR spectroscopy the stereochemistry of the 1-methyl-1-benzothiepinium ring system was investigated both in thermodynamic and kinetic respects. It was shown that in solution a rapid mutual conversion of the boat shaped seven membered ring system with exo-respectively endo-S-methyl group occurs via a ring inversion and not by a pyramidal inversion at the sulfonium ion. At room temperature predominantly the conformation with the exo-S-methyl group is present.

scholarly journals The photoisomerization of cis,trans-1,2-dideuterio-1,4-diphenyl-1,3-butadiene in solution. No bicycle-pedal

2019 ◽  
Vol 18 (9) ◽  
pp. 2174-2179
Author(s):  
Jack Saltiel ◽  
Christopher E. Redwood ◽  
Ratheesh Kumar V. K.
Keyword(s):  
Nmr Spectroscopy ◽  
Room Temperature ◽  
H Nmr

cis,trans-1,2-Dideuterio-1,4-diphenyl-1,3-butadiene (ct-DPBd2) was synthesized and its cis–trans photoisomerization in cyclohexane-d12 (C6D12) at room temperature was monitored by 1H NMR spectroscopy.

Transmission Infrared Spectroscopy of Ammonia Borane

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
P. Jash ◽  
K. Meux ◽  
M. Trenary
Keyword(s):  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Ammonia Borane ◽  
Residual Water ◽  
Hydrogen Storage Materials ◽  
High Quality ◽  
Host Matrix ◽  
Complex Hydrides

Transmission infrared spectroscopy can potentially offer unique advantages in studying the mechanisms of hydrogen loss from complex hydrides that are being considered for use as hydrogen storage materials. An apparatus that permits infrared spectra to be obtained over a temperature range of 85 to 1200 K and under either an ambient pressure of selected gases or under vacuum has been designed and its performance characterized. While the method is capable of producing high quality spectra at room temperature and below, several difficulties arise as the sample temperature is increased to the point where hydrogen loss occurs. These challenges include reaction with the host matrix, reaction with residual water or oxygen in the system, and loss of transparency of the sample. The performance of the method is illustrated with spectra obtained for ammonia borane, NH3BH3.

Nitrosyl complexes of rhenium. 3. The synthesis and substitution reactions of [ReH(CH3OH)(NO)(PPh3)3]ClO4 derived from the reaction of ReH2(NO)(PPh3)3 with HClO4. Members of the series ReHX(NO)(PPh3)3

1989 ◽  
Vol 67 (7) ◽  
pp. 1187-1192 ◽  
Author(s):  
Julie Y. Chen ◽  
Kevin R. Grundy ◽  
Katherine N. Robertson
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Ambient Conditions ◽  
Substitution Reactions ◽  
Rhenium Complexes ◽  
Counter Ion ◽  
Elemental Analyses ◽  
Neutral Ligands ◽  
Hydrogen Bound

ReH2(NO)(PPh3)3 reacts with alcoholic HClO4 to yield the solvated cation, [ReH(ROH)(NO)(PPh3)3]ClO4 (R = CH3, C2H5) which can be isolated as an explosive solid (R = CH3 only). In the solid state, the perchlorate counter ion is hydrogen bound to the ligated alcohol, as observed for [ReH(CH3OH)(CO)(NO)(PPh3)2]ClO4. This latter complex also results from the reaction of [ReH(CH3OH)(NO)(PPh3)3]ClO4 with CO under ambient conditions. On reaction with p-tolylisocyanide (RNC), however, substitution is also accompanied by dihydrogen elimination to give [Re(OR)(NO)(CNR)2(PPh3)2]ClO4, irrespective of the mole ratio of the reactants. In contrast, [ReH(CH3OH)(NO)(PPh3)3]ClO4 reacts with coordinating anions with loss of methanol to give air-sensitive ReHX(NO)(PPh3)3 (X = OCH3, F, Cl, Br, I, N3, NCO, SCN), of which only those with X = Cl, Br, N3 were characterized in solution. The compounds ReHX(NO)(PPh3)3 are similar to their osmium analogues in having a labile third phosphine. Thus, reaction with neutral ligands such as CO or RNC leads to the series of neutral rhenium hydrido nitrosyls ReHX(L)(NO)(PPh3)2. Prior to this work, the only known examples from this series were those with L = CO, X = H, F, OCH3. Interestingly, the isomer of ReHF(CO)(NO)(PPh3)2 isolated in this work differs from that previously isolated (from the reaction of [ReF(CO)(NO)(PPh3)3]+ with [Formula: see text]) in having F trans to NO. All structural assignments have been made on the basis of elemental analyses, infrared spectroscopy, 1H and 31P nmr spectroscopy and deuteration studies, where appropriate. Keywords: hydrido, nytrosyl, rhenium, complexes.

scholarly journals Stereochemistry of Two Hydroxybiflavanonols from Garcinia cola Nuts

1987 ◽  
Vol 42 (7-8) ◽  
pp. 855-857 ◽  
Author(s):  
Johann Sonnenbichler ◽  
Ifeanyi Madubunyi ◽  
Hugo Scheer
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Room Temperature ◽  
H Nmr ◽  
The Absolute

The absolute configuration of two hydroxybiflavanonols from Garcinia cola nuts have been determined by CD and 500 MHz 1H NMR spectroscopy. Additionally the occurrence of atrop-isomers at room temperature as the consequence of rotational hindrance in the molecules could be demonstrated.

scholarly journals Antibacterial, Cytotoxic Studies and Characterization of Some Newly Synthesized SymmetricalN3,N3′-Bis(disubstituted)isophthalyl-bis(thioureas) and Their Cu(II) and Ni(II) Complexes

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad Jamil ◽  
Muhammad Zubair ◽  
Muhammad Asim Farid ◽  
Umer Rashid ◽  
Nasir Rasool ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Magnetic Moments ◽  
Cytotoxic Activities ◽  
Spectral Measurements ◽  
Neutral Complex ◽  
H Nmr ◽  
Cytotoxic Studies ◽  
C Nmr

A series of some novelN3,N3′-bis(disubstituted)isophthalyl-bis(thioureas) compounds with general formula [C6H4·{CONHCSNHR}2], where R = 2-ClC6H4S (L1), 3,5-(Cl)2C6H3(L2), 2,4-(Cl)2C6H3(L3), 2,5-(Cl)2C6H3(L4), and 2-NH2C6H4(L5), and their Cu(II) and Ni(II) complexes (C1–C10) have been synthesized. These compounds (L1–L5) and their metal(II) complexes (C1–C10) have been characterized by elemental analysis, infrared spectroscopy,1H NMR and13C NMR spectroscopy, magnetic moments, and electronic spectral measurements. The ligands are coordinated to metal atom in a bidentate pattern producing a neutral complex of the type [ML]2. These compounds (L1–L5) and their metal(II) complexes (C1–C10) were also screened for their antibacterial and cytotoxic activities.

Synthesis and characterization of [MII(bqb)] (M = Co, Ni, Cu), [N(n-Bu)4][CoIII(bqb)(CN)2], and [N(n-Bu)4][CoIII(bqb)(N3)2] containing deprotonated N,N'-bis(2-quinolinecarboxamide)-1,2-benzene (bqb) – X-ray crystal structures of [NiII(bqb)] and [N(n-Bu)4][CoIII(bqb)(N3)2]

2006 ◽  
Vol 84 (7) ◽  
pp. 971-978 ◽  
Author(s):  
Soria Meghdadi ◽  
Mehdi Amirnasr ◽  
Vratislav Langer ◽  
Alison Zamanpoor
Keyword(s):  
Crystal Structures ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Square Planar ◽  
Distorted Octahedral ◽  
Elemental Analyses

Cobalt(II), nickel(II), copper(II), and two cobalt(III) complexes of a new dianionic ligand, bqb, [H2bqb = N,N'-bis(2-quinolinecarboxamide)-1,2-benzene] have been synthesized and characterized by elemental analyses, IR, and 1H NMR spectroscopy. The crystal and molecular structures of the [Ni(bqb)] (2) and [N(n-Bu)4][CoIII(bqb)(N3)2] (5) complexes were determined by X-ray crystallography. Complex 2 crystallizes in the monoclinic space group C2/c with a distorted square-planar structure including two short Ni–N (1.848 Å) and two long Ni–N (1.958 Å) bonds. The structure consists of sheets formed in the plane parallel to the b axis and diagonal to vectors a and c by intermolecular hydrogen bonds. Complex 5 crystallizes in the monoclinic space group C2 with a distorted octahedral structure. The [N(n-Bu)4]+ ion is disordered at the C3A and C4A atoms of one Bu. The IR and 1H NMR spectra of the complexes are also discussed.Key words: N4-dianionic amido ligand (bqb), (bqb) complexes of Co(II), Ni(II), Cu(II), and Co(III), azide, cyanide, X-ray crystal structures.

scholarly journals An ionic Cd/Hg mixed-metal complex with an aminoalcohol ligand

2018 ◽  
Vol 73 (12) ◽  
pp. 959-963
Author(s):  
Zahra Mardani ◽  
Reza Kazemshoar-Duzduzani ◽  
Keyvan Moeini ◽  
Majid Darroudi ◽  
Cameron Carpenter-Warren ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Metal Complex ◽  
Ionic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Metal ◽  
H Nmr ◽  
Distorted Octahedral ◽  
Ft Ir

AbstractA cadmium–mercury mixed-metal complex of cis-2-((2-((2-hydroxyethyl)amino)ethyl)amino)cyclohexan-1-ol (HEAC), [Cd(HEAC)2][HgI4] (1), was prepared and identified by elemental analysis, FT-IR, 1H NMR spectroscopy, and single-crystal X-ray diffraction. The X-ray analysis revealed an ionic structure for 1 in which the cadmium and mercury atoms have CdN4O2 and HgI4 environments, with distorted octahedral and tetrahedral geometries, respectively. The packing of the components in the crystal of 1 is supported by O–H···I hydrogen bonds, and these interactions lead to the formation of an ${\rm{R}}_4^4$(22) motif.

Synthese unsymmetrischer Trissilylamine mit gehinderter Bindungsrotation / Synthesis of Unsymmetrical Trissilylamines with Rotational Barrier

1991 ◽  
Vol 46 (9) ◽  
pp. 1149-1160 ◽  
Author(s):  
Simone Walter ◽  
Uwe Klingebiel ◽  
Mathias Noltemeyer ◽  
Dieter Schmidt-Bäse
Keyword(s):  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Room Temperature ◽  
Rotational Barrier ◽  
Structural Isomer ◽  
Structural Isomers ◽  
Silyl Groups

Bis- and tris(fluorosilyl)amines with bulky groups are prepared in the reaction of lithiated di-tert-butylfluorosilylamine with fluorosilanes. Tris(fluorosilyl)amines with three different silyl groups could be synthesized stepwise in these reactions.In all tris(fluorosilyl)amines a rotational barrier is observed by NMR spectroscopy at room temperature. The compounds 7, 8, 11 and 12 show only one structural isomer, whereas the compounds 10, 13 and 14 show two structural isomers. To prove the conclusion drawn from the spectra, the crystal structures of 10 and 12 were determined.

Application of NMR Spectroscopy to the Study of Piperidine Derivatives. Part III: Molecular Dynamics Study of N-Benzyl-4-[N-Benzyloxyacetyl)-(2-Fluorophenyl)]Amino-3-Methyl Piperidine

1993 ◽  
Vol 47 (3) ◽  
pp. 357-359 ◽  
Author(s):  
A. L. Cholli ◽  
M. L. Lau
Keyword(s):  
Molecular Dynamics ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Detailed Analysis ◽  
Room Temperature ◽  
Variable Temperature ◽  
Proton Nmr ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Nmr Data

High-resolution 1H NMR has been used to study the molecular dynamics of the piperidine derivative. Detailed analysis of variable temperature NMR data allowed the identification of the origin of two sets of methyl resonance peaks with unequal intensities in the room-temperature proton NMR spectrum of the compound.

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