TY - JOUR
T1 - 99Ru NMR spectroscopy of organometallic and coordination complexes of ruthenium(II)
AU - Gaemers, Sander
AU - Van Slageren, Joris
AU - O'Connor, Christine M.
AU - Vos, Johannes G.
AU - Hage, Ronald
AU - Elsevier, Cornelis J.
PY - 1999/12/6
Y1 - 1999/12/6
N2 - 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 by means of 99Ru NMR spectroscopy. The 99Ru NMR resonances for these compounds are generally sharp, allowing scalar couplings to group 14 nuclei to be observed. Correlation times τc have been determined from NOE factors and 13C T1 values for selected compounds and 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. In the series M - Ru - M′ a correlation between the inverse of the crystal field splitting energy ΔE and δ(99Ru) exists. These complexes have a HOMO which is delocalized over the M - Ru - M′ σ system and a LUMO which has predominantly π*-DAB character; therefore, (ΔE)-1 is dominant in the paramagnetic shielding of the ruthenium nucleus. The difference in the observed chemical shift regions of the M - Ru - M′ and M - Ru - X compounds can be attributed to differences in d-orbital radius 〈r-3〉d, which is in good agreement with previously performed DFT calculations. For the Ru(I)(R)(CO)2(i-Pr-DAB) complexes, δ(99Ru) follows the same trend as for a series of iron compounds, indicating an increase of the Ru - C bond length in the series Me < Et < neo-Pe < i-Pr. This finding emphasizes the power of transition-metal NMR spectroscopy in the structural analysis of transition-metal complexes. Furthermore, 99Ru NMR 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 ruthenium complexes are found at different frequencies, which can be used to unambiguously identify coordination isomers in mixtures by means of 99Ru NMR spectroscopy. The δ(99Ru) value is found to increase with increasing redox potential of the polypyridyl compounds.
AB - 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 by means of 99Ru NMR spectroscopy. The 99Ru NMR resonances for these compounds are generally sharp, allowing scalar couplings to group 14 nuclei to be observed. Correlation times τc have been determined from NOE factors and 13C T1 values for selected compounds and 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. In the series M - Ru - M′ a correlation between the inverse of the crystal field splitting energy ΔE and δ(99Ru) exists. These complexes have a HOMO which is delocalized over the M - Ru - M′ σ system and a LUMO which has predominantly π*-DAB character; therefore, (ΔE)-1 is dominant in the paramagnetic shielding of the ruthenium nucleus. The difference in the observed chemical shift regions of the M - Ru - M′ and M - Ru - X compounds can be attributed to differences in d-orbital radius 〈r-3〉d, which is in good agreement with previously performed DFT calculations. For the Ru(I)(R)(CO)2(i-Pr-DAB) complexes, δ(99Ru) follows the same trend as for a series of iron compounds, indicating an increase of the Ru - C bond length in the series Me < Et < neo-Pe < i-Pr. This finding emphasizes the power of transition-metal NMR spectroscopy in the structural analysis of transition-metal complexes. Furthermore, 99Ru NMR 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 ruthenium complexes are found at different frequencies, which can be used to unambiguously identify coordination isomers in mixtures by means of 99Ru NMR spectroscopy. The δ(99Ru) value is found to increase with increasing redox potential of the polypyridyl compounds.
UR - http://www.scopus.com/inward/record.url?scp=0000729975&partnerID=8YFLogxK
U2 - 10.1021/om990477n
DO - 10.1021/om990477n
M3 - Article
AN - SCOPUS:0000729975
SN - 0276-7333
VL - 18
SP - 5238
EP - 5244
JO - Organometallics
JF - Organometallics
IS - 25
ER -