Calculated Exp. BI-NMeS BI-NMeS dimer BI-NMeSH BI-NSMe (Conf1) BI-NSMe(Conf2) Average A 7.0 7.1 7.3 7.8 7.2 7.4 7.3 7.2 B 7.3 7.4 7.3 7.4 7.3 7.3 7.3 7.2 C 7.3 7.4 7.2 7.3 7.4 7.4 7.3 7.2 D 7.0 7.3 7.0 7.2 7.8 7.8 7.4 7.3 E* 3.7 4.1 3.6 3.6 2.7 2.4 3.3 2.8 F 7.9 8.1 11.2 4.9 7.7 7.8 7.9 7.5

*Averaged values for the methyl hydrogens

Table 1: The calculated and experimental [21] 1H NMR chemical shifts in ppm.