Quantum mechanical exchange coupling in polyhydride and dihydrogen complexes
Article Abstract:
Transition metal hydride complexes are interesting because of their value in homogeneous catalysis and of their spectroscopic properties. Examples of complexes with quantum mechanical exchange couplings are sandwich and half-sandwich trihydrides, sandwich dihydrides, and octahedral polyhydrides. These compounds do not have structural commonalities. Their similarity lies in the fact that they all have an exchange barrier for two hydrogens of approximately 40 kilo-joule per mole. Polyhydrides have a low barrier while dihydrogen compounds possess a high barrier.
Publication Name: Chemical Reviews
Subject: Chemistry
ISSN: 0009-2665
Year: 1998
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Fluorinated carbanions
Article Abstract:
Perfluoroalkyl carbanions occur as intermediates in fluorocarbon chemistry and help in the study of nucleophilic additions to fluorinated alkenes, carboxylate fragmentations, and deprotonation reactions. The structure of fluorinated carbanion has a planar carbanion center. The anion is dynamic and shows (3,3)-sigmatropic rearrangements in partially fluorinated species. These carbanions participate in nucleophilic perfluoroalkylation reactions for carbon-carbon bond formation.
Publication Name: Chemical Reviews
Subject: Chemistry
ISSN: 0009-2665
Year: 1996
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Ligand substitution reactions at inorganic centers
Article Abstract:
A discussion on ligand substitution at inorganic centers is presented with emphasis given to reactions at cationic transition metal centers specifically involving water ligand exchange and replacement processes. Subtle changes to the coordination geometry, neighboring ligands, and marginal steric effects could profoundly affect the rate and mechanism of ligand substitution, a finding that is of direct relevance to the low symmetry inorganic centers present in biology.
Publication Name: Chemical Reviews
Subject: Chemistry
ISSN: 0009-2665
Year: 2005
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