Rationalize the following signal multiplicities in the ¹¹⁹Sn NMR spectra of some halo-anions and, where possible, use the data to distinguish between geometric isomers [¹⁹F 100% I = 1/2]: 

(a) [SnCl₅F]²⁻ doublet; 

(b) [SnCl₄F₂]²⁻ isomer A, triplet; isomer B, triplet; 

(c) [SnCl₃F₃]²⁻ isomer A, doublet of triplets; isomer B, quartet; 

(d) [SnCl₂F₄]²⁻ isomer A, quintet; isomer B, triplet of triplets; 

(e) [SnClF₅]²⁻ doublet of quintets; 

(f) [SnF₆]²⁻ septet.