1H and13C NMR data to aid the identification and quantification of residual solvents by NMR spectroscopy

2005 ◽  
Vol 43 (6) ◽  
pp. 497-509 ◽  
Author(s):  
Ian C. Jones ◽  
Gary J. Sharman ◽  
Julia Pidgeon
Keyword(s):  
Nmr Spectroscopy ◽  
1H And13c Nmr ◽  
Residual Solvents ◽  
Nmr Data ◽  
Identification And Quantification

Unexpected Keto-enol Tautomerism in the Cyclopyridinophane Class Direct and indirect proofs

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Paul Ionut Dron ◽  
Neculai Doru Miron ◽  
Gheorghe Surpateanu
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Stable Conformer ◽  
Ph Measurements ◽  
Theoretical Methods ◽  
Nmr Data ◽  
Tautomeric Forms ◽  
New Compounds

The paper presents the synthesis of cyclo (bis-paraquat p-phenylene p-phenylene-carbonyl) tetrakis (hexafluorophosphate), named �CETOBOX�, and the closely related structural determinations. This compound exists in three tautomeric forms. These forms were evidentiated by NMR-data (1H-NMR, TOCSY, COSY, NOESY), UV-Vis spectra coupled with pH measurements and by synthesis. As the �CETOBOX� gives �in situ� only the corresponding monoylide, the synthesis of a new fluorescent indolizine cyclophane has been performed by a 3+2 cycloaddition. All structures of the new compounds presented herein have been established by NMR spectroscopy. Also, theoretical methods (MM3, AM1, AM1-COSMO and B88LYPDFT) have been used to determine the most stable conformer structures.

Equilibrium,1H and13C NMR Spectroscopy, and X-ray Diffraction Studies on the Complexes Bi(DOTA)-and Bi(DO3A-Bu)

2003 ◽  
Vol 42 (7) ◽  
pp. 2342-2349 ◽  
Author(s):  
Éva Csajbók ◽  
Zsolt Baranyai ◽  
István Bányai ◽  
Ernő Brücher ◽  
Róbert Király ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
X Ray Diffraction ◽  
1H And13c Nmr ◽  
X Ray ◽  
1H And13c Nmr Spectroscopy

Investigation by NMR spectroscopy of the structural characteristics of modified oligo-nucleotides with pendant porphyrins

2019 ◽  
Vol 23 (07n08) ◽  
pp. 797-812 ◽  
Author(s):  
Sonja Merkaš ◽  
Mladen Žinić ◽  
Régis Rein ◽  
Nathalie Solladié
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Characteristics ◽  
Strong Interactions ◽  
Light Harvesting Complexes ◽  
The Past ◽  
Naturally Occurring ◽  
Nmr Data ◽  
Intermolecular Distances ◽  
Uracil Base ◽  
Biopolymer Scaffolds

During the past years, we focused on exerting control over the position and distance of porphyrins along our specifically designed oligonucleotidic scaffold. Indeed, in naturally occurring light-harvesting complexes, biopolymer scaffolds hold pigments at intermolecular distances that optimize photon capture, electronic coupling, and energy transfer. To this end, four uridine-porphyrin conjugates (a monomer, a dimer, a tetramer and an octamer) were subjected to a comprehensive conformational analysis by using NMR spectroscopy. The collected NOE NMR data highlighted characteristic and strong interactions indicating that the glycosidic angle between the ribose and uracil base is anti. In order to further investigate the conformation of this family of molecules, NMR experiments were carried out at variable temperatures. At low temperature, the signals of the porphyrinic protons decoalesce, showing two sets of [Formula: see text]-pyrrolic protons. Similar observations are made for signals corresponding to sugar moieties and especially the H1′ protons, indicating molecular motions within our porphyrin-uridin arrays. These results testify in favor of the existence of a dynamic process between C3′-endo and C2′-endo conformations.

Hexaethyl-2,4-dicarba-nido-hexaborane(8), Deprotonation and Complexation Studied by NMR Spectroscopy and Density Functional Theory (DFT) Calculations

2004 ◽  
Vol 59 (6) ◽  
pp. 685-691 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Analogous Reaction ◽  
Sandwich Complex ◽  
Dft Methods ◽  
Functional Theory ◽  
Nmr Data

Deprotonation of hexaethyl-2,4-dicarba-nido-borane(8) 2 leads first to the hexaethyl-2,4-dicarbanido- borate(1−) 3, and further deprotonation, using BuLi/KOtBu, gives the hexaethyl-2,4-dicarbanido- hexaborate(2−) 4. The reaction of 3 with FeCl2 affords the commo-ferracarborane [Fe(Et6-2,4- C2B4H)2] 5, and the analogous reaction of 4 leads to the anionic sandwich complex [Fe(Et6-2,4- C2B4)2]2− 6 which can be protonated to give 5. The complex 5 contains two hydrido ligands, each bridging the iron and two boron atoms. Reactions were monitored and the products were characterised by 11B NMR spectroscopy in solution. The geometries of the carboranes, the borates (all unsubstituted and permethyl-substituted) and the iron complexes (all unsubstituted) were optimised by DFT methods [B3LYP/6-311+G(d,p) or B3LYP/6-31+G(d)], and the relevant NMR data [chemical shifts δ11B, δ13C, δ57Fe, and coupling constants 1J(13C,1H), 1J(11B,1H), 1J(57Fe,1H), 1J(57Fe,11B)] were calculated at the same level of theory.

Oligophosphin-Liganden, III [1] Bis(3-diphenylphosphinopropyl)phenylphospbinchloroiridium(I) * * und dessen Carbonyl-und Hydridderivate / Oligophosphine Ligands, III [1] Bis(3-diphenylphosphinopropyl)phenylphosphinechloroiridium(I) and its Carbonyl and Hydride Derivatives

1981 ◽  
Vol 36 (6) ◽  
pp. 672-676 ◽  
Author(s):  
Ertugrul Arpac ◽  
Lutz Dahlenburg
Keyword(s):  
Nmr Spectroscopy ◽  
Title Complex ◽  
Trigonal Bipyramidal Geometry ◽  
Trigonal Bipyramidal ◽  
Nmr Data ◽  
Ir And Nmr Spectroscopy ◽  
Infrared Intensities

AbstractThe title complex, IrCl(bdpp) (1), where bdpp = PhP[(CH2)3PPh2]2, has been obtained from [IrCl(C8H14)2]2 and the triphosphine ligand. Characteristic 31P NMR data of 1 dissolved in THF are δ(P̲Ph2) = 2.7 and δ(P̲Ph) = - 19.9 with cis-2J(P̲IrP̲) = 32.8 Hz. Reaction of 1 with CO proceeds stepwise to yield five-coordinate IrCl(CO)(bdpp) (2) and ionic [Ir(CO)2(bdpp)]Cl (3). A trigonal bipyramidal geometry with equatorial CO ligands is assigned to the cation of 3 on the basis of its v(CO) infrared intensities. When allowed to react with HCl, 1 gives the monohydride IrHCl2(bdpp) (4). Similarly, the dihydride IrH2Cl(bdpp) (5) is formed from 1 and H2. As has been established by IR and NMR spectroscopy, 4 and 5 adopt cis-mer-octahedral structures.

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