Topic
Steric effects
About: Steric effects is a research topic. Over the lifetime, 16112 publications have been published within this topic receiving 319615 citations. The topic is also known as: steric hindrance.
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TL;DR: In this paper, an experimental study of the stability and coordination of oxygen-and nitrogen-containing ligands in association with Mg2+ in the gas phase has been undertaken.
Abstract: An experimental study of the stability and coordination of oxygen- and nitrogen-containing ligands in association with Mg2+ in the gas phase has been undertaken. The ligands chosen exhibit a wide range of physical properties in terms of their ionization energies, dipole moments, and polarizabilities, and a simple electrostatic model reveals a semiquantitative trend between these properties and the ability of each ligand to stabilize Mg2+. The model clearly demonstrates why water is extremely effective at stabilizing Mg2+, and in this respect, CO2 also proves to be a good ligand. Evidence of a discrete first solvation shell is apparent only for those ligands which do not display hydrogen bonding. For water, methanol, and ethanol, hydrogen bonding leads to extended solvation units for which the boundaries are less obvious. However, for more complex alcohols, steric interactions appear to negate the influence of hydrogen bonding. Discrete solvation shells are observed for most aprotic ligands, and the optimu...
86 citations
TL;DR: Using a pulsed high-pressure mass spectrometer, the hydrogen-bonded dimer ions BH/sup +/B and monohydrates BH /sup +/.H/sub 2/O of 2-alkylpyridines, 2,6-dialkylpyridine, and tertiary amines were investigated in the gas phase in the absence of solvent effects as discussed by the authors.
Abstract: Using a pulsed high-pressure mass spectrometer, the hydrogen-bonded dimer ions BH/sup +/.B and monohydrates BH/sup +/.H/sub 2/O of 2-alkylpyridines, 2,6-dialkylpyridines, and tertiary amines were investigated in the gas phase in the absence of solvent effects. Steric hindrance causes major entropy effects unfavorable to dimerization or hydration. As long as a single confirmation exists in which the hydrogen bond can obtain optimal geometry, the bond strength is not weakened by steric crowding. However, steric crowding may result in major entropy effects by the hindrance of internal rotors in dimers and monohydrates. 8 figures, 3 tables.
86 citations
86 citations
TL;DR: In this article, the interaction of electronic and steric factors in aromatic azomethine molecules has been investigated and theoretical calculations predict and the experimental data confirm that the azogenine molecule exists as a stable non-planar conformation in which the dihedrical angle between the amino nucleus and the rest of the molecule plane is 40-60° and that substituents in the aryl nucleus have little effect.
86 citations
TL;DR: The coordination number of the metal in iron(II) beta-diketiminate complexes can be tuned through the size of the alkyl substituents on the ligand backbone.
86 citations