Table 1. Overview of the Main Photodegradation Products for the Lignin Model Compounds of Figure 2Aa.
| GC analyses |
1H NMR analyses |
RIs analyses | ||||
|---|---|---|---|---|---|---|
| compound | α-carbon | # -OCH3 | YCO (%) | YCH3OH (%) | other products | [OH•]ss (10–16 M) |
| H1 | alcohol | 0 | n.s. | n.d. | ≈1.5¤ | |
| G1 | alcohol | 1 | 11.5 ± 1.4, 12.6 ± 2.6§ | 28.8 ± 3.2 | 4.5 ± 0.3 | |
| GD1 | alcohol | 1 | 11.7 ± 0.5§ | 36.3 ± 1.1 | 1,2-propanediol | 3.7 ± 0.5 |
| GD2 | alcohol | 1 | 14.4 ± 0.2§ | 18.7 ± 1.3 | ≈1.8¤ | |
| S1 | alcohol | 2 | 10.2 ± 1.4 | 73.7 ± 2.8 | 2.6 ± 0.6 | |
| H2 | ketone | 0 | 2.2 ± 0.7 | n.d. | acetate | 14.3 ± 1.0 |
| G2 | ketone | 1 | 17.6 ± 2.1 | 23.1 ± 1.5† | acetate | 23.4 ± 1.5 |
| S2 | ketone | 2 | 11.2 ± 0.2 | 73.4 ± 1.4†† | acetate | 31.0 ± 2.5 |
a
CO conversion efficiencies (YCO) were calculated via eq 4 with the blank-corrected CO concentration after 6 h of UV irradiation (no mark, 6 lamps; §, 12 lamps; n.s., not significant). CH3OH conversion efficiencies (YCH3OH) were obtained via eq 6 using the methanol concentration at the end of the experiment (no mark, 6 h irradiation; †, 4 h irradiation; ††, 2 h irradiation; n.d., not detected). [OH•]ss were obtained from BA degradation via eq 7 (no mark) or were estimated from the p-hydroxybenzoate production rate of GD1 (¤). All errors are obtained from error propagation.