99Ru NMR Spectroscopy of Organometallic and Coordination Complexes of Ruthenium(II)
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- 作者：Sander Gaemers ; Joris van Slageren ; Christine M. O'Connor ; Johannes G. Vos ; Ronald Hage ; and Cornelis J. Elsevier
- 刊名：Organometallics
- 出版年：1999
- 出版时间：December 6, 1999
- 年：1999
- 卷：18
- 期：25
- 页码：5238 - 5244
- 全文大小：116K
- 年卷期：v.18,no.25(December 6, 1999)
- ISSN：1520-6041
文摘
The ruthenium(II) organometallic and coordination complexes of type Ru(X)(Y)(CO)2(i-Pr-DAB) (i-Pr-DAB = 1,4-diisopropyl-1,4-diaza-1,3-butadiene; X, Y = Cl, Br, I, Me, Et,i-Pr, neo-Pe, Ph3Sn, Me3Sn, Ph3Pb, Ph3Ge, Mn(CO)5, RuCp(CO)2) have been analyzed bymeans of 99Ru NMR spectroscopy. The 99Ru NMR resonances for these compounds aregenerally sharp, allowing scalar couplings to group 14 nuclei to be observed. Correlationtimes 
c have been determined from NOE factors and 13C T1 values for selected compoundsand were found to parallel the molecular weight of the compounds studied. The M-Ru-M'and M-Ru-X complexes have 99Ru NMR resonances in distinct chemical shift regions. Inthe series M-Ru-M' a correlation between the inverse of the crystal field splitting energy
E and 
(99Ru) exists. These complexes have a HOMO which is delocalized over the M-Ru-M' 
system and a LUMO which has predominantly 
*-DAB character; therefore, (E)-1 isdominant in the paramagnetic shielding of the ruthenium nucleus. The difference in theobserved chemical shift regions of the M-Ru-M' and M-Ru-X compounds can be attributedto differences in d-orbital radius <r-3>d, which is in good agreement with previously performedDFT calculations. For the Ru(I)(R)(CO)2(i-Pr-DAB) complexes, (99Ru) follows the same trendas for a series of iron compounds, indicating an increase of the Ru-C bond length in theseries Me < Et < neo-Pe < i-Pr. This finding emphasizes the power of transition-metal NMRspectroscopy in the structural analysis of transition-metal complexes. Furthermore, 99RuNMR provides a tool to identify and assign isomers in mixtures of Ru-polypyridyl complexes.The 99Ru NMR resonances of coordination isomers of various triazole-containing rutheniumcomplexes are found at different frequencies, which can be used to unambiguously identifycoordination isomers in mixtures by means of 99Ru NMR spectroscopy. The (99Ru) value isfound to increase with increasing redox potential of the polypyridyl compounds.
c have been determined from NOE factors and 13C T1 values for selected compoundsand were found to parallel the molecular weight of the compounds studied. The M-Ru-M'and M-Ru-X complexes have 99Ru NMR resonances in distinct chemical shift regions. Inthe series M-Ru-M' a correlation between the inverse of the crystal field splitting energyE and (99Ru) exists. These complexes have a HOMO which is delocalized over the M-Ru-M' system and a LUMO which has predominantly *-DAB character; therefore, (E)-1 isdominant in the paramagnetic shielding of the ruthenium nucleus. The difference in theobserved chemical shift regions of the M-Ru-M' and M-Ru-X compounds can be attributedto differences in d-orbital radius <r-3>d, which is in good agreement with previously performedDFT calculations. For the Ru(I)(R)(CO)2(i-Pr-DAB) complexes, (99Ru) follows the same trendas for a series of iron compounds, indicating an increase of the Ru-C bond length in theseries Me < Et < neo-Pe < i-Pr. This finding emphasizes the power of transition-metal NMRspectroscopy in the structural analysis of transition-metal complexes. Furthermore, 99RuNMR provides a tool to identify and assign isomers in mixtures of Ru-polypyridyl complexes.The 99Ru NMR resonances of coordination isomers of various triazole-containing rutheniumcomplexes are found at different frequencies, which can be used to unambiguously identifycoordination isomers in mixtures by means of 99Ru NMR spectroscopy. The (99Ru) value isfound to increase with increasing redox potential of the polypyridyl compounds.