I will probably edit this to add more as requested, but I have access to the original article.
As an example of how they characterized these molecules, here is the data they present for the "NanoChef":
Mp: 117-124 °C. IR (KBr): 2966, 2929, 2900,
2867, 2225, 1580, 1481, 1350, 1230, 1022 cm-1. 1H NMR (400
MHz, CDCl3): δ 7.63 (s, 1 H), 7.60 (s, 1 H), 7.47 (d, J ) 1.5
Hz, 2 H), 7.40 (t, J ) 1.5 Hz, 1 H), 7.22 (s, 1 H), 6.89 (m, 4 H),
2.39 (t, J ) 7.0 Hz, 4 H), 1.62 (sext, J ) 7.2 Hz, 4 H), 1.35 (s,
9 H), 1.29 (s, 9 H), 1.05 (t, J ) 7.2 Hz, 6 H). 13C NMR (100
MHz, CDCl3): δ 147.6, 136.2, 135.7, 134.4, 133.6, 129.8, 126.8,
125.9, 124.6, 123.3, 122.2, 121.7, 108.6, 108.0, 106.0, 104.9,
92.7, 91.4, 88.1, 79.4, 75.0, 30.9, 30.7, 28.3, 22.1, 21.3, 13.5.
HRMS: calcd for C43H42O2 590.3185, found 590.3178.
So it appears they looked at melting point, IR, $\ce{H}$ NMR, and $\ce{^13C}$ NMR, as well as determining High Resolution Mass Spectrometry.