Conjugative and steric factors affecting the conformational preference of some aromatic sulfides

1972 ◽  
Vol 37 (3) ◽  
pp. 504-505 ◽  
Author(s):  
G. Montaudo ◽  
F. Bottino ◽  
E. Trivellone
Keyword(s):  
Conformational Preference ◽  
Factors Affecting ◽  
Steric Factors

Nickel(II) and palladium(II) complexes with acylhydrazone ligands of α-diketones: the electronic and steric factors affecting the formation of the dimeric palladium(II) complexes

1999 ◽  
Vol 295 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Alessia Bacchi ◽  
Mauro Carcelli ◽  
Paolo Pelagatti ◽  
Corrado Pelizzi ◽  
Giancarlo Pelizzi ◽  
...  
Keyword(s):  
Factors Affecting ◽  
Steric Factors

Investigation of Factors Affecting Conformational Preference in Complex Haloethane Derivatives by Classical Energy Calculations

1973 ◽  
Vol 51 (16) ◽  
pp. 2659-2670 ◽  
Author(s):  
William F. Reynolds ◽  
Donald J. Wood
Keyword(s):  
Solvation Energy ◽  
Coupling Constants ◽  
Conformational Preference ◽  
Factors Affecting ◽  
Energy Calculations ◽  
Vicinal Coupling Constants ◽  
Classical Energy ◽  
Dipole Interactions ◽  
Related Compounds ◽  
Good Agreement

Classical energy calculations are used in combination with Abraham's electrostatic theory of solvation energy to estimate rotamer energy differences for haloethane derivatives. The calculations are tested by comparing experimental and calculated ΔE values for several di- and tetrahaloethanes. There is good agreement for chloro and bromo derivatives but poorer agreement for fluoro and iodo derivatives. ΔE values in solution are also estimated for l4 complex chloro- and bromoethanes which we have previously investigated by n.m.r. spectroscopy. The calculations generally parallel the experimental results as reflected by vicinal coupling constants. They are particularly useful for trends in conformational preference for closely related compounds and are used in conjunction with vicinal coupling constants to identify diastereomers produced by halogenation of alkenes. Steric interactions, dipole–dipole interactions and solvation energy are all important in determining conformational preference for complex haloethanes in solution.

scholarly journals Effects of charge states, charge sites and side chain interactions on conformational preferences of a series of model peptide ions

The Analyst ◽  
2015 ◽  
Vol 140 (20) ◽  
pp. 6933-6944 ◽  
Author(s):  
Chunying Xiao ◽  
Lisa M. Pérez ◽  
David H. Russell
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Gas Phase ◽  
Dynamics Simulation ◽  
Side Chain ◽  
Peptide Ions ◽  
Conformational Preference ◽  
Model Peptide ◽  
Factors Affecting ◽  
Conformational Preferences

The factors affecting conformational preference of gas phase peptide ions are investigated by IM-MS and molecular dynamics simulation.

Factors affecting product formation in the photolysis of α-spirocyclopropyl ketones

1983 ◽  
Vol 61 (5) ◽  
pp. 936-945 ◽  
Author(s):  
Peter Yates ◽  
Patrick Hugh Helferty
Keyword(s):  
Solvent Effect ◽  
Product Formation ◽  
Major Product ◽  
Ring Size ◽  
Factors Affecting ◽  
Hydrocarbon Solvents ◽  
Steric Factors

Photolysis of spiro[2.5]oct-7-en-4-ones results in exclusive β-cleavage in methanol to give 2-ethenylcyclohex-2-en-1-ones and in hydrocarbon solvents to give (E)- and (Z)-2-ethylidenecyclohex-3-en-1-ones. The solvent effect is ascribed to the role of methanol in stabilizing trienol intermediates and engendering their intermolecular ketonization. Photolysis of 8-methylenespiro[2.5]octan-4-ones in methanol gives 2-ethenylcyclohex-2-en-1-ones and bicyclo[4.3.0]non-1(6)-en-2-ones; irradiation in methanol-O-d indicates that the former type of product is formed mainly via a trienol intermediate. Photolysis of 8-methylenespiro[2.5]octan-4-ones in benzene gives 2-ethenylcyclohex-2-en-1-ones together with (E)- and (Z)-2-ethylidene-3-methylenecyclohexan-1-ones; the latter undergo photoconversion to the former during the irradiation. 6,6-Dimethylspiro[2.4]-heptan-4-one on photolysis in methanol undergoes ct-cleavage to give 4-methoxy-7,7-dimethyl-5-oxaspiro[2.5]octane as the major product, whereas under the same conditions 6,6-dimethylspiro[2.5]octan-4-one is reduced to the corresponding alcohol and 6,6,8-trimethylspiro[2.5]octan-4-one undergoes β-cleavage to give 2-ethyl-3,5,5-trimethylcyclohexan-1-one as the major primary product; this trichotomy is interpreted in terms of ring-size and steric factors.

Configuration and conformation of alkoxyalkyl and hydroxyalkyl trifluoromethyl nitroxides. Anomeric effects and nitroxide conformations

1981 ◽  
Vol 59 (12) ◽  
pp. 1745-1752 ◽  
Author(s):  
C. Chatgilialoglu ◽  
K. U. Ingold
Keyword(s):  
Anomeric Effect ◽  
Conformational Preference ◽  
Nodal Plane ◽  
Spectral Parameters ◽  
Small Magnitude ◽  
Or Groups ◽  
Steric Factors ◽  
Hyperfine Splittings ◽  
Anomeric Effects ◽  
Configuration And Conformation

The epr spectral parameters for some [Formula: see text] radicals have been measured over a range of temperatures. These radicals are probably non-planar at nitrogen. Their OR groups are in the eclipsed position with respect to the N 2pz orbital, a conformational preference which is attributed to a combination of steric factors and the anomeric effect. For [Formula: see text] the H hyperfine splittings (hfs) are of unusually small magnitude. It is pointed out that all other known [Formula: see text] also have anomalously low H hfs. It is suggested that this is due to the anomeric effect which not only promotes the eclipsed conformation but also causes the OR group to bend towards the semioccupied orbital, thereby moving H and R2 towards the nodal plane of this orbital.

Steric Factors affecting the Specificity of Polyglycosidases

Nature ◽  
1960 ◽  
Vol 187 (4743) ◽  
pp. 1110-1111 ◽  
Author(s):  
F. W. PARRISH ◽  
A. S. PERLIN
Keyword(s):  
Factors Affecting ◽  
Steric Factors

Factors Affecting the Conformational Preference and Magnetic Shielding of Isobutenylene Chains in Macrocyclic Salicylideneaniline Derivatives

2003 ◽  
Vol 76 (12) ◽  
pp. 2405-2411 ◽  
Author(s):  
Hirohiko Houjou ◽  
Seiji Tsuzuki ◽  
Yoshinobu Nagawa ◽  
Masatoshi Kanesato ◽  
Kazuhisa Hiratani
Keyword(s):  
Magnetic Shielding ◽  
Conformational Preference ◽  
Factors Affecting
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