Results 261 to 270 of about 134,654 (299)

Substituent effects in cyclopolyphosphines

Journal of the Chemical Society, Chemical Communications, 1974
For cyclopolyphosphines, (RP)n, a linear relationship which is independent of the ring size, n, exists between the electrochemical reduction potential of the ring and the inductive effect of the pendant organic group.
Timothy J. DuPont, Lawrence R. Smith, Jerry L. Mills   +2 more
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Stereodirective Effects in Mixed Substituent Vinyloxycyclotriphosphazenes

Inorganic Chemistry, 2009
Reaction pathways leading to the new mixed substituent cyclophosphazenes, N(3)P(3)Cl(4)(OCH=CH(2))(OCH(2)CF(3)) and N(3)P(3)Cl(3)(OCH=CH(2))(OCH(2)CF(3))(2), have been explored. Examination of the relative isomeric yields and the spectroscopic properties of these new derivatives gave insight into the mechanism of substitution of cyclophosphazenes with ...
Kenneth R, Carter, Michael, Calichman, Christopher W, Allen   +2 more
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Substituent effects in π-(tricarbonylchromium)arenes

Journal of Organometallic Chemistry, 1976
Abstract the IR wavenumbers and half-band width's of the carbonyl stretching vibrations of several substituted 7r-(tricarbonylchromium)benzenes in isooctane solution are reported. only small perturbations of C3,.symmetry are observed. the shape of the out-of-phase band is influenced by electronic effects, conformer distribution and solute-solvent ...
F van Meurs, J.M van der Toorn, H van Bekkum   +2 more
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Substituent effects in anthrasemiquinones

Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1988
Electron spin resonance spectra have been obtained from series of 2-substituted anthrasemiquinones and of 3-substituted 1,8-dihydroxyanthra-semiquinones. The proton splittings are consistently assigned by means of linear correlation plots between splitting constants and a substituent-dependent parameter.
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Substituent Effects in Discotic Liquid Crystals

Molecular Crystals and Liquid Crystals, 2004
A series of novel mesogens have been prepared by a five-fold Sonogashira reaction of terminal acetylenes with a functionalized pentabromophenol. The corresponding side chain polymers were prepared by a polymer analogous substitution reaction. The mesogens differ in the nature of the substituents, linking five hexyl tails to the aromatic core, i.e. CH2,
Kouwer, P.H.J., Jager, W.F., Mijs, W.J., Picken, S.J.   +3 more
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Recent progress of quantifying substituent effects

SCIENTIA SINICA Chimica, 2013
This paper summarizes significant progress in quantifying organic substituent effects in the last 20 years. The main content is as follows: (1) The principle of electronegativity equalization has gained wide acceptance, and has been used to calculate the intramolecular charge distribution and inductive effect of groups. A valence electrons equalization
ChenZhong Cao, YaXin Wu
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ChemInform Abstract: SUBSTITUENT EFFECTS PART 12, SUBSTITUENT EFFECTS BY (19)F NMR

Chemischer Informationsdienst, 1975
AbstractFMMF‐Berechnungen für die chemischen Verschiebungen von (19)F in 10‐substituierten 9‐Fluor‐anthracenen und 4‐substituierten 3,5‐Dimethyl‐fluorbenzolen, substituierten Arylfluoriden (z.T.
W. ADCOCK, M. J. S. DEWAR, R. GOLDEN, M. A. ZEB   +3 more
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Substituent Effects on Folding in Cyclotetraphosphane

Chemische Berichte, 1991
Ab initio quantum chemical calculations evidence a very flat potential hypersurface for folding of parent cyclotetraphosphane. This is in accord with a corresponding vibrational analysis. Electronegative substituents increase folding of the fourmembered ring system.
Schoeller, Wolfgang, BUSCH, T
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Purine stacking: Effects of alkyl substituents

Biochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 1968
Abstract The association behavior of various alkyl-substituted purines in aqueous solution was investigated by nuclear magnetic resonance and vapor pressure osmometry. The data suggested that stacking was highly dependent on the nature and location of the alkyl substituent.
G K, Helmkamp, N S, Kondo
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Chemometric Analysis of Substituent Effects. VIII. Alternative Interpretation of Substituent Effects (AISE)

Collection of Czechoslovak Chemical Communications, 1995
Alternative interpretation of substituent effects (AISE) starts from the presumption that a substituent only possesses a single property described by a single substituent constant. This property is transmitted to the reaction centre by three different ways depending on the interaction type in the triad reaction centre - basic skeleton - substituent ...
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