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

Abstract

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.

First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

“…This discussion is divided into three main parts following the order established in the methodology section. Initially, it is worth mentioning that the validation step of the theoretical methodology was based on another work about NMR platinum complexes developed by Paschoal and collaborators (2017) [27]. In this research, the authors developed a basis set with relativistic correction for Pt(II) chemical shift calculations [27].…”

“…Initially, it is worth mentioning that the validation step of the theoretical methodology was based on another work about NMR platinum complexes developed by Paschoal and collaborators (2017) [27]. In this research, the authors developed a basis set with relativistic correction for Pt(II) chemical shift calculations [27]. Moreover, for the validation step, we used two different methodologies for the platinum atom.…”

“…The authors performed several NMR chemical shift calculations for many Pt(II) complexes using different theoretical methodologies. Then, a comparison was made among the three different methodologies [27].…”

“…After this step, NMR calculations were performed using NMR-DKH basis set, as follows: (PBEPBE/NMR-DKH/IEFPCM(UFF)//B3LYP/LANL2DZ/Def2-TZVPP/IEFPCM(UFF)) (Model 2) and (PBEPBE/NMR-DKH/IEFPCM(UFF)//B3LYP/LANL2DZ/Def2-SVP/IEFPCM(UFF)) (Model 3). Then, a comparison was performed using a Hamiltonian relativistic operator (ZORA), as follows: COSMO-PBE-SO-ZORA/TZ2P (Model 1) [27]. A statistical study using absolute deviation (MAD) and the relative deviation (MRD) were employed for a methodology comparison.…”

Trans‐philicity (trans‐influence/trans‐effect) ladders for square planar platinum(II) complexes constructed by 35Cl NMR probe

“…The PBE0 functional mixes the Perdew–Burke–Ernzerhof (PBE) exchange energy and Hartree‐Fock exchange energy in a set 3:1 ratio, along with the full PBE correlation energy. Geometry optimization of the square planar trans ‐[Pt(NH 3 ) 2 (Cl)L] 0/+ and trans ‐[Pt(CO) 2 (Cl)L] 0/+ complexes was done in solution using for Pt central atom the segmented all‐electron relativistically contracted Douglas–Kroll–Hess (DKH) Gaussian basis sets (abbreviated as NMR‐DKH basis sets) developed recently by Paschoal and co‐workers and for all main group elements (E) the 6–31 + G(d) basis set was used. Hereafter the computational protocol used in DFT calculations of trans ‐Pt(NH 3 ) 2 (Cl)L and trans ‐[Pt(CO) 2 (Cl)L] 0/+ complexes is abbreviated as PBE0/NMR‐DKH(Pt) ∪ 6–31 + G(d)(E)/PCM.…”