Studies in aryltin chemistry. Part 5. Tin-119 and carbon-13 NMR spectra of some tetra- and tri-aryltin compounds

Abstract

Tin-119 and carbon-13 NMR data are reported for Ar 4Sn and Ar 3SnX (X = Cl, Br, I) where Ar = p-YC 6H 4 (Y = H, F, Cl, CH 3, CH 3O, CH 3S) as well as ( p-PhC 6H 4) 4Sn, all in CDCl 3. The 119Sn chemical shifts in all series are unusual in that electron-donating substituents cause shifts to higher frequency (less shielding) from the parent phenyltin compound and two series correlate well with substituent constants, Ar 4Sn (σ R or σ° R) and Ar 3SnI (σ p or σ° p) if the Y = H points are omitted. All four series show good correlation ( r > 0.95) with pairs of substituent constants (σ I, σ R) or (σ I, σ° R); again the Y = H data must be omitted for this to be the case. Tin-119 spectra of ( p-YC 6H 4) 3SnNCS in CDCl 3 show 119Sn- 14N coupling when Y = H, CH 3, and Ph, but not with Y = F or Cl. n J( 119Sn- 13C) values for all four systems correlate well ( r > 0.95) with the same substituent parameters (σ R or σ° R) while carbon-13 chemical shifts vary with σ R in the same way for all four groups of compounds.