Gschwind, R. M. and Xie, X. and Rajamohanan, P. R. and Auel, C. and Boche, G. (2001) Me(2)CuLi*LiCN in diethyl ether prefers a homodimeric core structure [Me(2)CuLi](2) and not a heterodimeric one [Me(2)CuLi*LiCN]: (1)H, (6)Li HOE and (1)H, (1)H NOE studies by NMR. Journal of the American Chemical Society 123 (30), pp. 7299-7304.
Full text not available from this repository.
H−Li distances and 1H−1H dipolar interactions in Me2CuLi*LiCN and Me2CuLi in diethyl ether (Et2O), obtained by NMR spectroscopy, were used to gain structural information about the contact ion pair of the salt-containing organocuprate Me2CuLi*LiCN in this solvent. The H−Li distances of Me2CuLi*LiCN and Me2CuLi in Et2O, resulting from the initial buildup rates in conjunction with the motional correlation times, are almost identical, indicating a similar homodimeric core structure [Me2CuLi]2 for both samples. However, the H−Li distances obtained for Me2CuLi*LiCN do not rigorously exclude a heterodimeric structure [Me2CuLi*LiCN] as proposed by ab initio calculations. Therefore, 1H−1H dipolar interactions were investigated by SYM-BREAK-NOE/ROE-HSQC experiments, which allow for the observation of NOEs between equivalent protons. Since these experiments showed similar 1H−1H dipolar interactions of Me2CuLi*LiCN and Me2CuLi, we propose that for Me2CuLi*LiCN a homodimeric core structure [Me2CuLi]2 indeed is predominant in Et2O.
|Institutions:||Chemistry and Pharmacy > Institut für Organische Chemie > Arbeitskreis Prof. Dr. Ruth Gschwind|
|Subjects:||500 Science > 540 Chemistry & allied sciences|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||No|
|Deposited On:||11 Nov 2009 17:09|
|Last Modified:||11 Nov 2009 17:09|