The Synthesis of 10-Halo-Substituted Derivatives of nido-7,8,9-PC2B8H11 and [nido-7,8,9-PC2B8H10]- and New Linear Correlations Between NMR Parameters

2005 ◽  
Vol 70 (11) ◽  
pp. 1861-1872 ◽  
Author(s):  
Josef Holub ◽  
Mario Bakardjiev ◽  
Bohumil Štíbr
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shifts ◽  
Proton Sponge ◽  
Nmr Chemical Shifts ◽  
Nmr Parameters ◽  
Neutral Compounds ◽  
Experimental Errors ◽  
Derivatives Of ◽  
Linear Correlations ◽  
Individual Cluster

Halogenation of the eleven-vertex phosphadicarbaborane nido-7,8,9-PC2B8H10 (1) with CCl4, Br2 or I2 in the presence of anhydrous AlCl3 (solvents CCl4, CS2, and benzene, respectively) generated a series of 10-X-nido-7,8,9-PC2B8H10 (10-X-1) compounds (X = Cl, Br, and I) in yields 55, 65, and 63%, respectively. Anionic compounds [10-X-nido-7,8,9-PC2B8H10]- (10-X-2) (X = Cl, Br, I) were obtained by treatment of the corresponding neutral compounds with "proton sponge" (PS = 1,8-bis(dimethylamino)naphthalene). All compounds were characterized by multinuclear (11B, 1H, and 31P) NMR spectroscopy and [11B-11B]-COSY and 1H-{11B(selective)} NMR measurements that led to complete assignments of all 11B and 1H resonances to individual cluster positions. Interesting halo-substitution NMR effects are also discussed in terms of new linear correlations. All the changes in NMR chemical shifts (∆) induced at the various skeletal sites by halogeno substituents on specific sites can be related to an arbitrary reference skeleton and are, within experimental errors, linearly proportional to those induced at the substituted site (∆α) of the reference skeleton.

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.

ChemInform Abstract: (19)F NMR CHEMICAL SHIFTS IN FLUOROPHENYL DERIVATIVES OF SILICON-PLATINUM COMPLEXES

1974 ◽  
Vol 5 (13) ◽  
pp. no-no
Author(s):  
C. EABORN ◽  
M. R. HARRISON ◽  
P. N. KAPOOR ◽  
D. R. M. WALTON
Keyword(s):  
Chemical Shifts ◽  
Platinum Complexes ◽  
Nmr Chemical Shifts ◽  
Derivatives Of ◽  
19 F Nmr

scholarly journals What can NMR spectroscopy of selenoureas and phosphinidenes teach us about the π-accepting abilities of N-heterocyclic carbenes?

2015 ◽  
Vol 6 (3) ◽  
pp. 1895-1904 ◽  
Author(s):  
Sai V. C. Vummaleti ◽  
David J. Nelson ◽  
Albert Poater ◽  
Adrián Gómez-Suárez ◽  
David B. Cordes ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shifts ◽  
Heterocyclic Carbenes ◽  
Carbene Ligands ◽  
Nmr Chemical Shifts ◽  
The Relationship

The relationship between the NMR chemical shifts of phosphinidene and selenourea compounds and the π-accepting ability of the related carbene ligands has been investigated.

Conformations and 13C NMR chemical shifts of some polyamides in the solid state as studied by high-resolution 13C NMR spectroscopy

1991 ◽  
Vol 29 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Kimihiro Kubo ◽  
Isao Ando ◽  
Toru Shiibashi ◽  
Takeshi Yamanobe ◽  
Tadashi Komoto
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
13C Nmr ◽  
Chemical Shifts ◽  
13C Nmr Spectroscopy ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts

19F NMR chemical shifts in fluorophenyl derivatives of silicon-platinum complexes

1973 ◽  
Vol 63 ◽  
pp. 99-105 ◽  
Author(s):  
C. Eaborn ◽  
M.R. Harrison ◽  
P.N. Kapoor ◽  
D.R.M. Walton
Keyword(s):  
Chemical Shifts ◽  
Platinum Complexes ◽  
19F Nmr ◽  
Nmr Chemical Shifts ◽  
Derivatives Of

Effets des sels de terres rares sur quelques phosphates dérivés des metabolites de la glycolyse

1991 ◽  
Vol 69 (8) ◽  
pp. 1281-1287 ◽  
Author(s):  
Claude Rabiller ◽  
Philippe Eymard ◽  
Mahmoud Mesbahi
Keyword(s):  
Nmr Spectroscopy ◽  
Key Words ◽  
Fermentation Process ◽  
Chemical Shifts ◽  
Deuterium Nmr ◽  
Sugar Fermentation ◽  
Phosphoglyceric Acid ◽  
Spectroscopy Studies ◽  
Sugar Derivatives ◽  
Derivatives Of

Phosphate derivatives of glucose and fructose are well-known intermediates in sugar fermentation. Proton and deuterium NMR spectroscopy studies of the fermentation process provide information about proton (deuteron) transfers that are likely to occur in such biotransformations. In this paper we describe the influence of complexation of those metabolites with praseodymium trichloride and of pH on their proton NMR chemical shifts. We determine the conditions under which all the protons of both the α. and β forms of these cyclic sugars are separated. Glucose-1 phosphate was found to be the most suitable derivative for this type of study. Furthermore, comparing the behaviour of these compounds with 2-phosphoglyceric acid allows us to specify the exact conformation of the latter. Key words: phosphate sugar derivatives, NMR, LIS effects.

Hydroacridines: part 29.15N NMR chemical shifts of 9-substituted 1,2,3,4,5,6,7,8-octahydroacridines and theirN-oxides-Taft, Swain-Lupton, and other types of linear correlations

2008 ◽  
Vol 46 (12) ◽  
pp. 1141-1147 ◽  
Author(s):  
Francisc Potmischil ◽  
Maria Marinescu ◽  
Alina Nicolescu ◽  
Călin Deleanu ◽  
Mihaela Hillebrand
Keyword(s):  
Chemical Shifts ◽  
Nmr Chemical Shifts ◽  
Linear Correlations

Silicon-29 NMR Spectra of tert-Butyldimethylsilyl and Trimethylsilyl Derivatives of Some Non-Rigid Diols

1997 ◽  
Vol 62 (5) ◽  
pp. 761-768 ◽  
Author(s):  
Magdalena Kvíčalová ◽  
Vratislav Blechta ◽  
Krzysztof Kobylczyk ◽  
Ryszard Piekos ◽  
Jan Schraml
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Independent Study ◽  
Bulky Substituent ◽  
New Correlation ◽  
Proton Donors ◽  
Experimental Errors ◽  
Trimethylsilyl Derivatives ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

29Si NMR spectra of trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBDMS) derivatives of selected diols were measured under standardized conditions (i.e., in diluted CDCl3 solutions). Application of the recently reported correlation between the chemical shifts in TMS and TBDMS derivatives revealed considerable and systematic deviations which exceeded experimental errors and error estimates from the correlation. Two possible explanations of the deviations are considered: interaction between the two bulky substituent groups and invalidity of the reported correlation for simple hydroxy derivatives. An independent study of analogous derivatives of monohydroxy compounds has shown that the linear correlation holds but the slope and intercept are significantly different from those reported previously on the basis of a study of amino acid derivatives. The data obtained for the diol derivatives fit the new correlation very well and no indication of an interaction between the bulky TBDMS groups was noticed. However, deviations do occur in branched diol derivatives in which branching reduces accessibility of the oxygen atoms surface to associate with proton donors. The largest deviation was found when intramolecular hydrogen bond was formed.

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