The spin-spin coupling can provide useful information for analysing the structure of a system and the extent of non-covalent bonds interactions.In this study,we present the isotropic NMR properties and spinspin coupli...The spin-spin coupling can provide useful information for analysing the structure of a system and the extent of non-covalent bonds interactions.In this study,we present the isotropic NMR properties and spinspin coupling involving ruthenium-ligand(Ru-L)bonds and other spin-spin interactions obtained from DFT calculations.The proton shift which in close proximity with the Ru and Cl(or O)atoms are characterised with lower and higher chemical shift respectively.Though Ru-Cl bond has longer bond length than all other Ru-L bonds,yet its spin-spin coupling is higher than others because of a very high contribution of PSO which is far higher than the contribution from FC terms.In all other Ru-L bonds,FC is the most significant Ramsey terms that define their spin-spin coupling.Both the isotropic and anisotropic shielding of the Hz of the pyrazole is lower than Hc of the cymene and the spin-spin coupling 3J(Hz…Hz)of the pyrazole are less than half of the 3J(Hc…Hc)of the cymene unit in the complexes.There is a little increase in both the 3J(Hc…Hc)and 3J(Hz…Hz)spin-spin coupling in the hydrolysed complexes compare to the non-hydrolysed complexes.The isotropic and anisotropic shielding tensor of Ru atoms increases in magnitude as the complexes get hydrolysed that could be ascribed to a more deshielding chemical environments.展开更多
基金financial support of Govan Mbeki Research and Development Centre,University of Fort Hare,South Africa
文摘The spin-spin coupling can provide useful information for analysing the structure of a system and the extent of non-covalent bonds interactions.In this study,we present the isotropic NMR properties and spinspin coupling involving ruthenium-ligand(Ru-L)bonds and other spin-spin interactions obtained from DFT calculations.The proton shift which in close proximity with the Ru and Cl(or O)atoms are characterised with lower and higher chemical shift respectively.Though Ru-Cl bond has longer bond length than all other Ru-L bonds,yet its spin-spin coupling is higher than others because of a very high contribution of PSO which is far higher than the contribution from FC terms.In all other Ru-L bonds,FC is the most significant Ramsey terms that define their spin-spin coupling.Both the isotropic and anisotropic shielding of the Hz of the pyrazole is lower than Hc of the cymene and the spin-spin coupling 3J(Hz…Hz)of the pyrazole are less than half of the 3J(Hc…Hc)of the cymene unit in the complexes.There is a little increase in both the 3J(Hc…Hc)and 3J(Hz…Hz)spin-spin coupling in the hydrolysed complexes compare to the non-hydrolysed complexes.The isotropic and anisotropic shielding tensor of Ru atoms increases in magnitude as the complexes get hydrolysed that could be ascribed to a more deshielding chemical environments.
