Predicting Pt-195 NMR chemical shift using new relativistic all-electron basis set

• Published in: Journal of computational chemistry Vol. 37; no. 26; pp. 2360 - 2373
• Main Authors: Paschoal, D., Guerra, C. Fonseca, de Oliveira, M. A. L., Ramalho, T. C., Dos Santos, H. F.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 05.10.2016; Wiley Subscription Services, Inc
• Subjects: ab initio; all-electron Gaussian basis set; Atoms & subatomic particles; Coefficients; Construction; Density; Density functional theory; Deviation; Electrons; Experimental data; Heavy metals; Ligands; Mathematical models; Molecular structure; NMR; NMR-DKH; Nuclear magnetic resonance; Platinum; platinum complexes; Pt-195 chemical shift; Relativism; relativistic effects; Structural analysis; structure prediction; ab initio; relativistic effects; NMR; NMR-DKH; Pt-195 chemical shift; structure prediction; platinum complexes; all-electron Gaussian basis set
• DOI: 10.1002/jcc.24461
• ISSN: 0192-8651

Predicting NMR properties is a valuable tool to assist the experimentalists in the characterization of molecular structure. For heavy metals, such as Pt‐195, only a few computational protocols are available. In the present contribution, all‐electron Gaussian basis sets, suitable to calculate the Pt‐195 NMR chemical shift, are presented for Pt and all elements commonly found as Pt‐ligands. The new basis sets identified as NMR‐DKH were partially contracted as a triple‐zeta doubly polarized scheme with all coefficients obtained from a Douglas–Kroll–Hess (DKH) second‐order scalar relativistic calculation. The Pt‐195 chemical shift was predicted through empirical models fitted to reproduce experimental data for a set of 183 Pt(II) complexes which NMR sign ranges from −1000 to −6000 ppm. Furthermore, the models were validated using a new set of 75 Pt(II) complexes, not included in the descriptive set. The models were constructed using non‐relativistic Hamiltonian at density functional theory (DFT‐PBEPBE) level with NMR‐DKH basis set for all atoms. For the best model, the mean absolute deviation (MAD) and the mean relative deviation (MRD) were 150 ppm and 6%, respectively, for the validation set (75 Pt‐complexes) and 168 ppm (MAD) and 5% (MRD) for all 258 Pt(II) complexes. These results were comparable with relativistic DFT calculation, 200 ppm (MAD) and 6% (MRD). © 2016 Wiley Periodicals, Inc. Pt‐195 NMR chemical shifts were calculated for 258 Pt(II) complexes with the empirical Model 3 (PBEPBE/NMR‐DKH/IEFPCM(UFF)//B3LYP/LANL2DZ/Def2‐SVP/IEFPCM(UFF)) proposed in this study. The calculated Pt‐195 NMR chemical shifts were predicted using the empirical equation: δ195Ptcalc = −0.9250σ − 2065.7558.