The results from the singlet oxygen quantum yield measurements on the diethoxycarbonyl-BODIPYs can be seen in While the ΦΔ varies greatly between solvents for some dyads, unlike Φem, there appears to be no direct correlation between 1 O2 quantum yield and solvent polarity. This is evident for 1c, which has the highest yield overall of 0.961 in nonpolar toluene, and a much lower yield of 0.075 in more polar acetonitrile. Compound 1d, which differs in structure from 1c only by the absence of a methyl group in position 9 of the anthracene subunit, does not have the same high yield in toluene. ΦΔ values of 1d have less variation than those of 1c, and its highest result of 0.515 is also recorded in toluene. Reference BODIPY-pyrene and anthracene dyads which lack ethoxycarbonyl groups in positions 2,6 of the BODIPY scaffold are summarized in Table (ESI). For 8-pyrenyl-1,3,5,7-tetramethylBODIPY, ΦΔ value of 0.088 was recorded in toluene which is consistent with strong fluorescence (ΦF = 0.926) in this solvent and thus can be explained by inefficient charge transfer in non-polar solvent environment. The methoxybenzene-substituted dyads 1e -g all have relatively low ΦΔ results in all solvents, the highest being recorded for 1f in toluene with a yield of 0.264. 1e is the least efficient 1 O2 generator of these three dyads, with a maximum value of 0.051 in THF. 1e also has very low Φem as stated previously, indicating that SOCT-ISC in this compound is potentially inefficient.