Journal ArticleDOI
Vinyllithium : dynamic behavior in tetrahydrofuran solution and comprehensive analysis of NMR spin-spin coupling constants
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TLDR
In this article, an 8:1 tetramer/dimer equilibrium in tetrahydrofuran-d 8 at -90 o C (1.6 M solution) was found.Abstract:
Vinyllithium (ViLi; isotopically labeled with 6 Li) is an 8:1 tetramer/dimer equilibrium in tetrahydrofuran-d 8 (THF-d 8 ) at -90 o C (1.6 M solution). In the presence of equilmolar amounts of TMEDA (tetramethylethylenediamine), the tretramer:dimer ratio is 1:13 in THF-d 8 at -80 o C (1.9 M solution). Dynamic NMR phenomena are observed in the ViLi tetramer: at -90 o C in THF-d 8 , a static aggregate is found, whereas at -60 o C rapid intraaggravate exchange of the four lithium sites indicates a fluxional tetramerread more
Citations
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Journal ArticleDOI
Role of Organolithium Aggregates and Mixed Aggregates in Organolithium Mechanisms
Journal ArticleDOI
Mixed AggregAte (MAA): A Single Concept for All Dipolar Organometallic Aggregates. 1. Structural Data
TL;DR: Organometallic Aggregates.
Book ChapterDOI
Advances in theoretical and physical aspects of spin-spin coupling constants
Rubén H. Contreras,Juan E. Peralta,Claudia G. Giribet,Martín C. Ruiz de Azúa,Julio C. Facelli +4 more
TL;DR: In this article, advances in the theoretical and physical aspects of spin-spin coupling constants are discussed, and an excellent example of the Born-Opperheimer approximation is obtained by measuring transitions among nuclear states that are modified by the interactions among magnetic nuclei, external magnetic field, and electrons, while theoreticians study the way the electronic wave function is modified owing to those interactions.
Journal ArticleDOI
Lithium enolates of simple ketones: structure determination using the method of continuous variation.
Lara R. Liou,Anne J. McNeil,Antonio Ramirez,Gilman E. S. Toombes,Jocelyn M. Gruver,David B. Collum +5 more
TL;DR: The method of continuous variation in conjunction with 6Li NMR spectroscopy was used to characterize lithium enolates derived from 1-indanone, cyclohexan one, and cyclopentanone in solution.
Journal ArticleDOI
Mixed Complexes Formed by Lithioacetonitrile and Chiral Lithium Amides: Observation of 6Li,15N and 6Li,13C Couplings Due to Both C−Li and N−Li Contacts
TL;DR: NMR spectroscopic studies have been performed on the mixed complexes formed by the lithium salt of acetonitrile and the chiral lithium amides in diethyl ether and tetrahydrofuran solvent, where the dimer undergoes fast exchange between ketenimine and bridged structures and the complex appears C(2)-symmetric on the N MR spectroscopy time scale.