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Aryl benzobisoxazole and aryl benzobisthiazole compounds in the solid state and in solution have completely different photoreactivity. In the solid state, intermolecular π-stacking interactions between these molecules lead to excimer formation. The excimer undergoes a photoinduced electron transfer to generate an ion radical pair. In the presence of oxygen, the anion radical transfers an electron to molecular oxygen to form superoxide. The cation radical undergoes bond cleavage followed by hydrogen abstraction and other reactions to form benzobisoxazoles (or benzobisthiazoles), benzonitriles, and benzamides. In solution, aryl benzobisoxazole and aryl benzobisthiazole molecules cannot readily π-stack, and therefore photoinduced electron transfer and its subsequent reactions do not occur. The compounds in solution are stable even after prolonged irradiation, suggesting that intermolecular π-stacking plays a very important role in photoreactivity for these molecules. Reversible redox reagents, such as ferrocene compounds, are found to retard the subsequent reactions from the photoinduced electron-transfer reaction and hence improve the photostability of poly{(benzo[1,2-d:5,4-d′]bisoxazole-2,6-diyl)-1,4-phenylene}.

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The solubility of calcium bromate monohydrate in water from (-20 to +100) °C has been determined, along with a differential thermal analysis curve indicating loss of water from (130 to 150) °C and decomposition to calcium bromide from (270 to 300) °C. The effect of calcium chloride on the solubility at room temperature is also reported.