AbstractSucrose in aqueous solution was inverted with IR‐120‐H as catalyst. IR‐120‐K promoted the inversion brought about by IR‐120‐H, and the reaction rate increased almost lineally with increasing concentration of 1R‐120‐K. The effect of incorporating with IRA‐411‐C1 was also studied. With IR‐120‐H as catalyst, the rate of inversion was very slightly decreased by the presence of IRA‐411‐C1, while with IR‐120‐H and IR‐120‐K, the retar