A trend can be found in the linear array of atoms in the four Ar-SF4-BCP-Cl compounds in Figure : the CAr-S bond lengths increase as the (hetero)arenes become increasingly electron deficient, i.e., in the order of 7 (1.817(1) Å) < 8 (1.820(1) Å) < 9 (1.8386(13) Å) < 17 (1.847(1) Å). This type of trend has been observed previously in other compounds containing an Ar-SF4 motif and is associated with an increase in ionic character in the CAr-S bond. The dramatic "downfield" shift in C NMR shift of the ipso carbon atom (CAr) from 7 to 17 is also consistent with this idea (note that the cross-ring C3 atom C shift is less impacted by remote arene functionalization but experiences the opposite trend).