DFT Calculation of ¹J(¹¹⁹Sn,¹³C) and ²J(¹¹⁹Sn,¹H) Coupling Constants in Di- and Trimethyltin(IV) Compounds

Abstract

We have tested several computational protocols, at the nonrelativistic DFT level of theory, for the calculation of 1J(119Sn, 13C) and 2J(119Sn, 1H) spin-spin coupling constants in di- and trimethyltin(IV) derivatives with various ligands. Quite a good agreement with experimental data has been found with several hybrid functionals and a double-zeta basis set for a set of molecules comprising tetra-, penta-, and hexa-coordinated tin(IV). Then, some of the protocols have been applied to the calculation of the 2J(119Sn, 1H) of the aquodimethyltin(IV) ion and dimethyltin(IV) complex with D-ribonic acid and to the calculation of 1J(119Sn, 13C) and 2J(119Sn, 1H) of the dimethyltin(IV)-glycylglycine and glycylhistidine complexes in water solutions. Solvent effects have been considered in these cases by including explicit water molecules and/or the solvent reaction field, resulting in a good agreement with experimental data. The proposed protocols constitute a helpful tool for the structural determination of di- and triorganotin(IV) derivatives.

Karplus‐Type Dependence of Vicinal 119Sn‐13C and 119Sn‐1H Spin‐Spin Couplings in Organotin(IV) Derivatives: A DFT Study

“…In contrast to the results obtained with the non-relativistic approach for 1 J and 2 J couplings, which showed a marked dependence on the functional used, [35] the results obtained for 3 J are almost independent on the particular functional and pure and hybrid ones seem to perform similarly, see Figure 2 and Table S1. Finally, regarding compound 14 discussed above, it seems that the non relativistic DFT approach cannot discriminate which conformer, between (ax,eq) and (eq,ax), is the most stable.…”

“…Differences, however, are small and non-systematic in contrast to what we found for 1 J( 119 Sn, 13 C), where the effect of the basis set was sizeable. [35] It is noteworthy that the calculation with the tight functions requires an ultrafine integration grid, as reported above, hence a whopping increase of computational time making the calculation with the larger basis set very expensive. …”

“…At the non-relativistic level, calculations were performed with the Gaussian 03 package. [41] We have selected several functionals, of both pure and hybrid type, similarly to our previous study on 1 J( 119 Sn, 13 C) and 2 J( 119 Sn, 1 H), [35] and a relatively small basis set as the double zeta valence plus polarization DZVP [42] for tin and the 6-31G** for lighter atoms; an integration grid of 99 radial shells and 302 angular points in each shell was employed. All geometries were optimized by using the B3LYP…”

“…[29,30] Regarding the calculation of the coupling constants it has been shown that even for moderately heavy nuclei scalar relativistic effects are not negligible. [31,32] In this context relativistic ZORA DFT calculation of n J( 119 Sn,X) (n = 1,2; X = 1 H, 13 C) have been reported [29,33,34] [35] allowed to correlate these couplings with the θ angle of the dimethylti-n(IV) moiety even in those cases where the aforementioned Lockhart-Manders equations fail. [12] Again, a systematic error compensation might be at the root of the observed good agreement.…”

Diorganotin(IV) N-acetyl-l-cysteinate complexes: Synthesis, solid state, solution phase, DFT and biological investigations

“…2 J( 119 Sn, 1 H) ( 2 J) coupling constants for NAC1 were calculated according to Ref. [47] by using the mPW1PW91 [48] hybrid functional and the 6-31G(d,p) basis set for the H, C, O atoms and the DZVP basis set for the Sn atom. All contributions to the coupling constants have been evaluated, namely the SD, DSO, PSO and FC terms, whereas only the total spin-spin coupling constants are discussed in the text.…”