“…The discovery of new photoacoustic molecular materials has been restricted by the paucity of systematic studies on factors affecting PA effects, which has led to poor guidance in the study of molecular photoacoustic contrast agent design [ 4 , 15 , 16 ]. Lately, the chemistry of [2 + 2] cycloaddition-cycloreversion reactions between tetracyanoethylene (TCNE), 7,7,8,8-tetracyanodimethane (TCNQ) or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanodimethane (F 4 -TCNQ) and ‘electronically chaotic’ alkynes were focused on [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. The consequent adducts, specifically those composed of F 4 -TCNQ formation, had excellent solubility and could be easily produced in high yields.…”