Fig. 5. Mass spectra of BTA dimers. The left panel shows the monodisperse BTA dimers (a) 13 (3-unit linker) (b) 14 (6-unit linker) (c) 15 (9-unit linker) (d) 16 (15-unit linker) (e) 17 (21-unit linker). The right panel shows the polydisperse BTA dimers (f) 23, (g) 24, (h) 25, (i) 26, (j) 27. Peaks corresponding to the M+ and M2+ ions are indicated. For the polydisperse samples, individual peaks are labelled with the number of ethylene glycol units in the chain.
