Complexation of 7-azaindole by the methylmercury(II) cation

1992 ◽  
Vol 70 (12) ◽  
pp. 2914-2921 ◽  
Author(s):  
Nathalie Dufour ◽  
Anne-Marie Lebuis ◽  
Marie-Claude Corbeil ◽  
André L. Beauchamp ◽  
Pascal Dufour ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Pyridine Ring ◽  
Coordination Mode ◽  
Pyrrole Ring ◽  
Chemical Shifts ◽  
Lone Pair ◽  
Major Influence ◽  
Large Displacements ◽  
Dmso Solution

Complexes of the types [CH3Hg(aza)], [CH3Hg(Haza)]X, and [(CH3Hg)2(aza)]X are obtained by reacting CH3HgOH and/or CH3HgX (X = NO3, ClO4) with 7-azaindole (Haza). The weakly acidic N1-H proton on the pyrrole ring is displaced by the hydroxide, whereas the perchlorate and nitrate salts lead to CH3Hg+ coordination to the N7 lone pair on the pyridine ring. Detailed analysis of the infrared spectra of the complexes and their N-deuterated derivatives provides diagnostic regions for eventual prediction of the coordination mode in other systems. All compounds are characterized by means of 1H, 13C, and 199Hg NMR spectra in DMSO solution and solid-state CP-MAS 13C spectra. Comparison of the solution and solid-state 13C spectra show that the species present in the solids remain undissociated in DMSO. Each type of complex can be identified from a characteristic pattern of large displacements of the ligand 13C signals. The 1H spectra are less informative because substitution of the N1-H proton by CH3Hg+ induces only minor shifts. Metal solvation appears to have a major influence on the 13C and 199Hg chemical shifts of the CH3Hg+ groups.

Spectroscopic Studies with N-Chloroarylsulphonamides: IR and 1H, 13C and 23Na Nmr Spectra of Sodium Salts of N-Chloro-Mono- and Di-Substituted-Benzenesulphonamides, 4-X-C6H4SO2NANCl (X = H; CH3; C2H5; F; Cl; Br; I or NO2) and i-X, j-YC6H3SO2NANCl (i-X, j-Y = 2,3-(CH3)2; 2,4-(CH3)2; 2,5-(CH3)2; 2-CH3, 4-Cl; 2-CH3, 5-Cl; 3-CH3, 4-Cl; 2,4-Cl2 or 3,4-Cl2)

2003 ◽  
Vol 58 (1) ◽  
pp. 51-56 ◽  
Author(s):  
◽  
J. D. D’Souza ◽  
B. H. Arun Kumar
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Infrared Spectra ◽  
Phenyl Ring ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectroscopic Studies ◽  
Sodium Salts ◽  
Experimental Chemical Shift ◽  
23Na Nmr

In an effort to introduce N-chloroarylsulphonamides of different oxydising strengths, sixteen sodium salts of N-chloro-mono- and di-substituted benzenesulphonamides of the configuration, 4- X-C6H4SO2NaNCl (where X = H; CH3; C2H5; F; Cl; Br; I or NO2) and i-X, j-YC6H3SO2NaNCl (where i-X, j-Y = 2,3-(CH3)2; 2,4-(CH3)2; 2,5-(CH3)2; 2-CH3,4-Cl; 2-CH3,5-Cl; 3-CH3,4-Cl; 2,4- Cl2 or 3,4-Cl2) are prepared, characterized through their infrared spectra in the solid state and NMR spectra in solution. The υN-Cl frequencies vary in the range 950 - 927 cm−1. Effects of substitution in the benzene ring in terms of electron donating and electron withdrawing groups have been considered, and conclusions drawn. The chemical shifts of aromatic protons and carbon-13 in all the N-chloroarylsulphonamides have been calculated by adding substituent contributions to the shift of benzene. Considering the approximation employed the agreement between the calculated and experimental chemical shift values for different protons or carbon-13 is quite good. Effects of phenyl ring substitution on chemical shift values of both 1H and 13C are also graphically represented in terms of line diagrams.

Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2/3/4-Substituted Phenyl)-2,4-Disubstituted Benzenesulphonamides, 2,4-(CH3)2/2-CH3-4-Cl/2,4-Cl2C6H3SO2NH(i-XC6H4) (i-X = H, 2-CH3, 3-CH3, 4-CH3, 2-Cl, 3-Cl, 4-Cl, 4-F, 4-Br)

2006 ◽  
Vol 61 (10-11) ◽  
pp. 600-606
Author(s):  
Savitha M. Basappa ◽  
Basavalinganadoddy Thimme Gowda
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Benzene Rings ◽  
Stretching Vibrations ◽  
Absorption Frequencies ◽  
C Nmr

Twenty six N-(2/3/4-substituted phenyl)-2,4-disubstituted benzenesulphonamides of the general formulae 2,4-(CH3)2C6H3SO2NH(i-XC6H4), 2-CH3-4-ClC6H3SO2NH(i-XC6H4) and 2,4- Cl2C6H3SO2NH(i-XC6H4), where i-X = H, 2-CH3, 3-CH3, 4-CH3, 2-Cl, 3-Cl, 4-Cl, 4-F or 4-Br, have been prepared, characterized and their infrared spectra in the solid state and 1H and 13C NMR spectra in solution studied. The infrared N-H stretching vibrational frequencies vary in the range 3298 - 3233 cm−1. Asymmetric and symmetric SO stretching vibrations appear in the ranges 1373 - 1311 cm−1 and 1177 - 1140 cm−1, respectively, while C-S, S-N and C-N stretching absorptions vary in the ranges 840 - 812 cm−1, 972 - 908 cm−1 and 1295 - 1209 cm−1, respectively. The various 1H and 13C NMR chemical shifts are assigned to the protons and carbon atoms of the two benzene rings in line with those for similar compounds. The incremental shifts due to the groups in the parent compounds have been computed by comparing the chemical shifts of the protons or carbon atoms in these compounds with those of benzene or aniline, respectively. The computed incremental shifts and other data were used to calculate the 1H and 13C NMR chemical shifts of the substituted compounds in three different ways. The calculated chemical shifts by the three methods compared well with each other and with the observed chemical shifts. It is observed that there are no particular trends in the variation of either the infrared absorption frequencies or the chemical shifts with the nature or site of substitution.

The Structure of 1,3-Enaminoketonatoboron Difluorides in Solution and in the Solid State

2003 ◽  
Vol 56 (12) ◽  
pp. 1209 ◽  
Author(s):  
Kuniaki Itoh ◽  
Kazuhiko Okazaki ◽  
Miki Fujimoto
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Electron Distribution ◽  
Chelate Ring ◽  
Chemical Shifts ◽  
Electron System ◽  
The Other ◽  
13C Nmr Spectra ◽  
X Ray ◽  
Tautomeric Forms

Nuclear magnetic resonance, infrared, and ultraviolet spectra and X-ray analysis of three 1,3-enaminoketonatoboron difluorides (BF2 complexes, (2a)–(2c)) both in solution and in the solid state have been recorded. Their structures are discussed in relation to the electron distribution in their chelate rings and in comparison with those of their parent compounds (1a)–(1c) and 1,3-diketonatoboron difluorides. C1 and C3 chemical shifts in the 13C NMR spectra indicated that the ketoamine and enolimine tautomeric forms may be present in equal amounts. Additionally, the phenyl groups participate in the delocalized π-electron system of the chelate ring. On the other hand, in the solid state, a comparison of the bond lengths by X-ray analysis provides information on processes occurring as contribution of the enolimine form increases. The information found may offer valuable suggestions for the reactivity and the structure of the products for the reactions of the BF2 complexes.

Assigning solid-state NMR spectra of aligned proteins using isotropic chemical shifts

2006 ◽  
Vol 183 (2) ◽  
pp. 329-332 ◽  
Author(s):  
Anna A. De Angelis ◽  
Stanley C. Howell ◽  
Stanley J. Opella
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Isotropic Chemical Shifts

Phosphorus-31 nuclear magnetic resonance spectra of methylplatinum(II) and methylpalladium(II) cations containing 4-substituted pyridine ligands

1979 ◽  
Vol 57 (9) ◽  
pp. 958-960 ◽  
Author(s):  
Howard C. Clark ◽  
Charles R. Milne
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Lone Pair ◽  
Coupling Constants ◽  
The Other ◽  
Pyridine Ligands ◽  
Trans Influence ◽  
Nuclear Magnetic Resonance Spectra

The 31P nmr spectra of the compounds cis-[M(CH3)(L)diphos]PF6, where M = Pd, Pt; L = 4-C5H4NX; X = CH3, H, NMe2, COOMe, COMe, CN; diphos = 1,2-bisdiphenylphosphino ethane, have been recorded. The 31P chemical shifts and 31P–195Pt coupling constants decrease regularly as the ρ values of the substituent on pyridine decrease. These trends are attributed to decreasing lone pair donation from phosphorus as the electron donating ability of the other ligands on the metal increases. The trans influence of the coordinated pyridine molecule, as measured by J(195Pt–31P), is greater than its cis influence on the phosphorus atoms.

A solid-state 17O NMR study of platinum-carboxylate complexes: carboplatin and oxaliplatin

2015 ◽  
Vol 93 (9) ◽  
pp. 945-953 ◽  
Author(s):  
Xianqi Kong ◽  
Victor Terskikh ◽  
Abouzar Toubaei ◽  
Gang Wu
Keyword(s):  
Solid State ◽  
Chemical Shifts ◽  
Lone Pair ◽  
Carboxylate Oxygen ◽  
Carboxylate Groups ◽  
Nmr Study ◽  
Nmr Characterization ◽  
Orbital Electron ◽  
Isotropic Chemical Shifts ◽  
Oxygen Atoms

We report synthesis and solid-state NMR characterization of two 17O-labeled platinum anticancer drugs: cis-diammine(1,1-cyclobutane-[17O4]dicarboxylato)platinum(II) (carboplatin) and ([17O4]oxalato)[(1R, 2R)-(−)-1,2-cyclohexanediamine)]platinum(II) (oxaliplatin). Both 17O chemical shift (CS) and quadrupolar coupling (QC) tensors were measured for the carboxylate groups in these two compounds. With the aid of plane wave DFT computations, the 17O CS and QC tensor orientations were determined in the molecular frame of reference. Significant changes in the 17O CS and QC tensors were observed for the carboxylate oxygen atom upon its coordination to Pt(II). In particular, the 17O isotropic chemical shifts for the oxygen atoms directly bonded to Pt(II) are found to be smaller (more shielded) by 200 ppm than those for the non-Pt-coordinated oxygen atoms within the same carboxylate group. Examination of the 17O CS tensor components reveals that such a large 17O coordination shift is primarily due to the shielding increase along the direction that is within the O=C–O–Pt plane and perpendicular to the O–Pt bond. This result is interpreted as due to the σ donation from the oxygen nonbonding orbital (electron lone pair) to the Pt(II) empty dyz orbital, which results in large energy gaps between σ(Pt–O) and unoccupied molecular orbitals, thus reducing the paramagnetic shielding contribution along the direction perpendicular to the O–Pt bond. We found that the 17O QC tensor of the carboxylate oxygen is also sensitive to Pt(II) coordination, and that 17O CS and QC tensors provide complementary information about the O–Pt bonding.

The effect of substitution on the conformation in para-substituted ethylene glycol dibenzoate molecules

1988 ◽  
Vol 66 (10) ◽  
pp. 2545-2552 ◽  
Author(s):  
Suzanne Deguire ◽  
François Brisse
Keyword(s):  
Solid State ◽  
Ethylene Glycol ◽  
Nmr Spectra ◽  
Bond Angle ◽  
Chemical Shifts ◽  
Bond Distance ◽  
Substitution Effect ◽  
Torsion Angles ◽  
Ir And Nmr Spectra ◽  
Infrared Frequencies

The series of ethylene glycol di-para-X-benzoates, where X = Me, OMe, CN, and NO2, has been studied by infrared spectroscopy and solid state CP/MAS 13C nuclear magnetic resonance. The crystal structures were established for X = Me and OMe. Bond distances, bond angles, and torsion angles were compared to those of related molecules (X = H, Ph, Cl). It was found that the conformation of the CO—O—CH2—CH2—O—CO sequence is either trans-trans-trans or trans-gauche-trans. (trans = t, gauche = g). The CH2—CH2 bond distance ranging from 1.471(2) to 1.499(3) Å is always very short. The O—CH2—CH2 bond angle is around 105° for the ttt conformation and 107° for the tgt conformation. It was confirmed that the infrared frequencies for the CH2 bending, CH2 wagging, C–C stretching, and CH2 rocking modes are observed at 1470–1485, 1335–1340, 975–980, 845–855 cm−1 and at 1460, 1370–1375, 1040, 895–900 cm−1 for the ttt and tgt conformations respectively. The substitution effect on the nmr chemical shifts, both in solution and the solid state, can be rationalized in terms of induction and resonance contributions. On the basis of the ir and nmr spectra, it is proposed that for both the p-NO2 and p-CN substituted molecules, for which no crystal structure has been established, the conformation of the methylenic sequence is trans-trans-trans.

Effect of lanthanide shift reagents on 1H NMR spectra of aminopyridines

1979 ◽  
Vol 44 (3) ◽  
pp. 908-911 ◽  
Author(s):  
Antonín Lyčka ◽  
Dobroslav Šnobl
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Electron Donor ◽  
Electron Acceptor ◽  
Nmr Spectra ◽  
Pyridine Ring ◽  
Chemical Shifts ◽  
Amino Group ◽  
H Nmr ◽  
Lanthanide Shift Reagents

The effect of Eu(dpm)3 and Pr(dpm)3 on the proton spectra of 2-amino-, 3-amino- and 4-aminopyridines has been studied by the 1H NMR spectroscopy in tetrachlomethane and deuteriochloroform at 25 °C. Relative changes of the induced chemical shifts of pyridine carrying electron-donor substituents (amino group) are the same as the values given in literature for pyridine ring with electron-acceptor substituents.

scholarly journals Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X’C6H4SO2NH(2-/3-XC6H4), where X’ = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

2005 ◽  
Vol 60 (1-2) ◽  
pp. 106-112 ◽  
Author(s):  
B. Thimme Gowda ◽  
Mahesha Shetty ◽  
K. L. Jayalakshmi
Keyword(s):  
Solid State ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
1H And 13C Nmr ◽  
Methyl Group ◽  
Benzene Rings ◽  
Stretching Vibrations ◽  
C Nmr

Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X’C6H4SO2NH(2-/3-XC6H4), where X’ = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN−H, absorb in the range 3285 - 3199 cm−1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm−1 and 1177 - 1148 cm−1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm−1 and 1304 - 1168 cm−1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X’C6H4SO2- and 4-X’C6H4SO2NH- groups in 4-X’C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X’C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

Qualitative Applications of the NMR Spectra of Alkylpyridines: Part I. Chemical Shifts of the Ring Protons

1968 ◽  
Vol 22 (4) ◽  
pp. 325-329 ◽  
Author(s):  
F. R. McDonald ◽  
A. W. Decora ◽  
G. L. Cook
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Pyridine Ring ◽  
Structural Information ◽  
Chemical Shifts ◽  
Shale Oil ◽  
Nmr Chemical Shift ◽  
Chemical Shift Data ◽  
Spectroscopic Identification ◽  
Shift Data

Spectroscopic identification of pyridine compounds isolated from complex substances such as shale oil is greatly aided by NMR chemical-shift data on the pyridine-ring protons. Chemical shifts of the ring protons in CCl4 and C6H6 solution and the differential shift of the protons in these two solvents are reported. A paramagnetic shift is observed in the directional character of the proton alpha to the nitrogen in the pyridine ring. These data are used to determine structural information from the spectrum of a mixture of pyridine homologs.

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