Use of high‐field 119 Sn NMR and the pairwise additivity model for chemical shifts in the identification of complexes in the SnBr 4 –KSCN–MeOH system

The interaction of SnBr 4 and KSCN in methanol solution has been studied by 119 Sn NMR at 149 MHz and −30°C. Evidence was obtained for the existence of both the cis and trans isomeric forms of SnBr 4 ·2MeOH. A pairwise additivity model for chemical shifts was used to explain the observed peaks and many of the possible species, SnBr n (NCS) 4‐n ·2MeOH. [SnBr n (NCS) 5‐n ·MeOH]‐ and [SnBr n (NCS) 6‐n 2− ], (n=0–4), and their somecies, forms were identified and shown to exist simultaneously in solution in complex equilibria. In some cases 119 Sn– 14 N coupling was observed. The implications for possible synthesis of these types of compounds and the necessity for measurement at high field are discussed.