Benchmark calculations of ²⁹Si–¹H spin–spin coupling constants across double bond

Abstract

Benchmark calculations of geminal and vicinal (29) Si-(1) H spin-spin coupling constants across double bond in three reference alkenylsilanes have been carried out at both DFT and SOPPA levels in comparison with experiment. At the former, four density functionals, B3LYP, B3PW91, PBE0 and KT3, were tested in combination with five representative basis sets. At the latter, three main SOPPA-based methods, SOPPA, SOPPA(CC2) and SOPPA(CCSD), were examined in combination with the same series of basis sets. On the whole, the wavefunction methods showed much better results as compared to DFT, with the most efficient combination of SOPPA/cc-pVTZ-su2 characterized by a mean absolute error of only 0.4 Hz calculated for a set of nine coupling constants in three compounds with a sample span of around 40 Hz.

Open‐chain unsaturated selanyl sulfides: stereochemical structure and stereochemical behavior of their 77Se–1H spin–spin coupling constants

“…The parameter‐free generalized gradient density functional theory (DFT) functional of Perdew, Burke, and Ernzerhof (PBE) with a predetermined amount of exact exchange known as PBE0 was employed in this case. This choice is based on the results of our recent work demonstrating its better performance in the calculations of spin–spin coupling constants involving p ‐elements as compared with more common DFT functionals, those like B3LYP or PW91 . As can be seen from the data presented in Table , the Fermi contact term by far dominates for both couplings, which justifies the utilization of the NJC approach in this case.…”

Computational 1H NMR: Part 1. Theoretical background

“…In the earlier publications, the LDBS scheme was successfully applied for the calculation of chemical shieldings (chemical shifts) at the Hartree–Fock and DFT levels in a number of simple benchmark molecules, in relatively large molecular systems, and even in the model forms of biological molecules such as simple dipeptides . Different LDBS schemes were also systematically used for the calculation of NMR parameters at the DFT and nonempirical levels of theory in a number of more recent publications by Rusakov and coworkers together with numerous related publications not cited herewith in view of their multiplicity.…”

Nonempirical calculations of the one‐bond 29Si–13C spin–spin coupling constants taking into account relativistic and solvent corrections

“…Compiled in Table are the results of the gas phase SOPPA(CC2)/aug‐cc‐pVTZ‐J calculations of 1 J(Si,C) within the locally dense basis set (LDBS) scheme (refer to succeeding texts) in the series of 60 silanes 1–60 . Based on our previous results, in particular, those dealing with the calculation of spin–spin coupling constants involving silicon, we applied this method as the most efficient combination of the level of theory and the quality of the basis set used for the calculations of spin–spin coupling constants. Four basic Ramsey's coupling contributions, namely Fermi contact ( J FC ), spin–dipolar ( J SD ), diamagnetic spin–orbital ( J DSO ), and paramagnetic spin–orbital ( J PSO ) terms, were taken into account, and the total values of 1 J(Si,C) were compared with the available experimental data taken from different sources for compounds 1 , 2 , 5 , 8 , and 12 ; 6 , 7 , 20 , and 21 ; 11 ; 13 ; 14 ; 15 and 32 ; 19 ; 31 ; 34 ; 36 and 38 ; 35 , 33 , and 37 ; 39 ; 40 ; 41 ; 45 ; 46 ; 47 ; 57 and 58 ;and 59 and 60…”

“…At the DFT level, we applied the hybrid functional of Perdew, Burke, and Ernzerhof with a predetermined amount of exact exchange, PBE0, used in combination with Sauer's aug‐cc‐pVTZ‐J basis set. Among the numerous DFT methods, it is one of the most efficient schemes for the calculation of spin–spin coupling constants, in particular, those involving silicon 1c …”

“…In continuation of our recent interest dealing with the calculation of spin–spin coupling constants involving silicon, in this paper, we performed theoretical calculations of the one‐bond silicon–carbon coupling constants, 1 J(Si,C) , in the representative series of silanes 1–60 taking into account solvent and relativistic effects. Actually, this is a first systematic study of the computational aspects of 1 J(Si,C) calculated at the second‐order polarization propagator approximation (SOPPA) level – one of the most versatile ab initio approach used nowadays for the theoretical calculation of spin–spin coupling constants .…”