scholarly journals How much do coulombic interactions stabilize a mesophase? Ion pair and non-ionic binary isosteric derivatives of monocarbaborates and carboranes

RSC Advances ◽  
2014 ◽  
Vol 4 (96) ◽  
pp. 53907-53914 ◽  
Author(s):  
Aleksandra Jankowiak ◽  
Ajan Sivaramamoorthy ◽  
Damian Pociecha ◽  
Piotr Kaszyński
Keyword(s):  
Binary Systems ◽  
Ion Pair ◽  
Coulombic Interactions ◽  
Derivatives Of

A comparison of two isosteric, ionic and non-ionic binary systems, provides a measure of coulombic interactions impact on mesophase stability in the absence of other factors.

The Ion Associates of Methyl-, Ethyl- and Isopropyl Derivatives of Dialkylaminoethyl Dialkylamidofluorophosphate with Bromophenol Blue

1992 ◽  
Vol 57 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha
Keyword(s):  
Extraction Efficiency ◽  
Ion Pairs ◽  
Amino Nitrogen ◽  
Ion Pair ◽  
Amide Group ◽  
Bromophenol Blue ◽  
Amino Group ◽  
Methyl Ethyl ◽  
Derivatives Of

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.

scholarly journals THE STEREOCHEMISTRY OF HALOGEN DISPLACEMENT BY NITRATE ION RACEMIZATION AND RETENTION OF CONFIGURATION IN THE SYNTHESIS OF DINITRATE ESTERS

1965 ◽  
Vol 43 (6) ◽  
pp. 1656-1660 ◽  
Author(s):  
L. D. Hayward ◽  
M. Jackson ◽  
I. G. Csizmadia
Keyword(s):  
Silver Nitrate ◽  
Steric Effect ◽  
Heterogeneous Reaction ◽  
Ion Pair ◽  
Alkyl Halides ◽  
Preferential Formation ◽  
Carbonium Ion ◽  
Carbonium Ions ◽  
And Inversion ◽  
Derivatives Of

The reaction of silver nitrate in dry acetonitrile with 2,5-dideoxy-2,5-diiodo-1,4;3,6-dianhydro-L-iditol resulted in formation of the dinitrate esters of the 1,4;3,6-dianhydrides of D-mannitol, D-glucitol, and L-iditol. Similarly both endo- and exo-nitrato groups were introduced in displacement of the endo-halogen in the 2-deoxy-2-iodo-5-O-acetyl and 2-deoxy-2-iodo-5-O-p-toluenesulfonyl derivatives of 1,4;3,6-dianhydro-L-iditol. Since both types of nitrato groups were stable to silver nitrate, the racemization occurred during the displacement and was attributed to formation of cyclic carbonium ion intermediates. The steric effect of the adjacent ring in the carbonium ions apparently suppressed the termolecular, ion-pair mechanism previously established for the metathesis of acyclic alkyl halides and caused preferential formation of the exo-nitrato derivatives.The heterogeneous reaction of meso-dibromostilbene with silver nitrate in acetic acid or acetonitrile gave meso-dihydrobenzoin dinitrate with overall retention of configuration. This result could be most readily reconciled with the contrasting sequence of retention and inversion previously reported for meso- and dl-2,3-dibromobutane if participation of neighboring phenyl groups occurred in the second displacement step.

New possibilities of applications of the Barker quasi-lattice theory. Prediction of gE and hE of binary systems whose one component is formed by n-alkanes

1979 ◽  
Vol 44 (6) ◽  
pp. 1698-1714 ◽  
Author(s):  
Vladimír Dohnal ◽  
Robert Holub ◽  
Jiří Pick
Keyword(s):  
Aromatic Hydrocarbons ◽  
Lattice Theory ◽  
Binary Systems ◽  
Derived Relations ◽  
Orientation Effects ◽  
The Given ◽  
Derivatives Of ◽  
Arbitrary Component ◽  
Excess Quantities ◽  
Good Agreement

For binary systems of the type an arbitrary component + n-alkane we derived relations, on the basis of the Barker theory and on the basis of the group contribution concept, for predicting gE and hE from one system to another when the n-alkane length is changed. To carry out the prediction it is not necessary to evaluate any adjustable parameters. The developed method was tested using a large number of different systems covering alcohols, amines, ketones, esters, chlorinated derivatives of hydrocarbons, aromatic hydrocarbons and n-alkanes from n-pentane to n-hexadecane. The results of predictions are in very good agreement with experimental data in the cases, when the n-alkanes involved are not longer than n-decane. Systematic regular deviations in hE in the cases, when at least one of n-alkanes involved is longer, can be explained by the presence of orientation effects in the pure longer n-alkanes. The correction suggested by us for these effects improves considerably results obtained. The developed method appears to be suitable for the systematic prediction of excess quantities of systems of the given type and represents an effective test of the Barker theory.

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