Figure 6 . FT-IR exploration of the H2S addition
reaction with styrene oxide (1a ) with [BDMAEEH][MeOAc]
as the catalyst.
The recycling ability of PIL is of great significance for practical
application in H2S conversion. The reuse of the catalyst
in this system is very simple. Taking [BDMAEEH][MeOAc] as an
example, 1.0 g styrene oxide (1a , 8.0 mmol) was fed into
autoclave with 50 mol% loading of catalyst (1.0 g, 4mmol) at 30 ºC for
2.0 h. After the reaction, the catalyst can be separated from the system
by water extraction without the participation of any organic solvent
(four times extraction, the volume ratio of water to PILs is 1.0)
(Figure S11 ). It is found that the lower phase after water
extraction contains only two products (1b and 1c )
(based on NMR analysis, Figure S12 ), which can be easily
separated from TLC. All the extracts were collected and combined, which
can be used in the next circulation after drying in a vacuum line at 40
°C for half an hour. It is found that the conversion of styrene oxide
(1a ) has no significant activity loss, demonstrating the good
robustness and recyclability of PIL (Figure 7 ) after seven
cycles (the first cycle was in the presence of fresh PILs).