Density Functional Study of Cobalt-59 Nuclear Magnetic Resonance Chemical Shifts and Shielding Tensor Elements in Co(III) Complexes
نویسندگان
چکیده
A density functional method has been used to successfully predict the isotropic 59Co nuclear magnetic resonance (NMR) chemical shifts of the following anionic, cationic and neutral Co(III) complexes: [Co(CN)6], [Co(NH3)6], [Co(NO2)6], [Co(NH3)4CO3], Co(acac)3, and [Co(en)3]. Isotropic chemical shifts are wellreproduced by using Wachters’ cobalt basis set and uniform 6-31G* basis sets on the light atoms, together with the use of the B3LYP hybrid functional. In addition, the principal elements of the 59Co shielding tensor (σ11, σ22, and σ33), the absolute shieldings of Co(CN)6 and Co(acac)3, and the Co-C bond length shielding derivative for Co(CN)6 are also in good agreement with previous experimental estimates. There are no obvious distinctions between the predicted shifts (or shielding tensor elements) of anionic and cationic complexes. The ability to successfully predict both shift trends, absolute shieldings, shielding tensor elements, and a vibrational shielding derivative for d6 transition metal complexes opens up new possibilities for probing metal ions in biological systems by using NMR spectroscopy.
منابع مشابه
Computational analysis of tris(1,2-ethanediamine) cobalt(III) complex ion: calculation of the Co shielding tensor using LF-DFT
The ligand-field density functional theory (LFDFT) approach is employed for calculations of the Co nuclear magnetic resonance (NMR) shielding tensor of all four diastereoisomers (kkk, kkd, kdd, and ddd) of tris(1,2ethanediamine) cobalt(III) complex ion, [Co(en)3] . The obtained values split into two groups according to the point group of the diastereoisomers. The influence of the individual rin...
متن کاملA DFT study of NMR parameters for MgO nanotubes
Magnesium oxide nanotubes of finite length are investigated by the Density Functional Theory (DFT) at the B3LYP/6-31G (d) level. The (6, 0) zigzag and (4, 4) armchair of MgO nanotubes were considered and nuclear magnetic resonance properties including isotropic and anisotropic chemical shielding parameters (CSI and CSA) were calculated for 25Mg and 17O atoms of the optimiz...
متن کاملA DFT study of NMR parameters for MgO nanotubes
Magnesium oxide nanotubes of finite length are investigated by the Density Functional Theory (DFT) at the B3LYP/6-31G (d) level. The (6, 0) zigzag and (4, 4) armchair of MgO nanotubes were considered and nuclear magnetic resonance properties including isotropic and anisotropic chemical shielding parameters (CSI and CSA) were calculated for 25Mg and 17O atoms of the optimiz...
متن کاملEffect of rotation and vibration on nuclear magnetic resonance chemical shifts: Density functional theory calculations
The effect of rotation and vibration on the nuclear magnetic resonance ~NMR! shielding constants was computed for HF, F2, N2, CO, and HBr. The shielding constants for H, C, N, O, and F nuclei were calculated using sum-over-states density functional perturbation theory ~SOS-DFPT!. Diatomic ro-vibrational states were calculated from a discrete variable representation using Morse potentials and po...
متن کاملAn Ab initio and chemical shielding tensors calculations for Nucleotide 5’-Monophosphates in the Gas phase
Structural and magnetic properties of purine and pyrimidine nucleotides (CMP, UMP, dTMP, AMP, GMP, IMP) were studied at different levels of ab initio molecular orbital theory. These calculations were performed at the hartree-fock level and density functional B3LYP methods. Geometries were fully optimized by following Cs symmetry restrictions. The standard 6-31G** basis set which includes polari...
متن کامل