Introduction of ferrocene-containing [2]rotaxanes onto siloxane, silsesquioxane and polysiloxanes via click chemistry

摘要

The reaction of N_3(CH_2)_3Si(OTMS)_3 (TMS = SiMe_3) with a dialkylammonium having hexynyl group 1, [FcCH_2NH_2CH_2C_6H_4-4-O(CH_2)_4CCH]PF_6 (Fc = Fe(C_5H_4)(C_5H_5)), in the presence of dibenzo[24]crown-8-ether (DB24C8) and [Cu{Fe(CN)_4}]PF_6 catalyst yielded the [2]rotaxane containing the dialkylammonium unit terminated by a bulky silyl group. Azides with a silsesquioxane group react similarly to form the corresponding [2]rotaxanes having a bulky silsesquioxane end group. The azide-functionalized polysiloxane, [-O-SiMe{(CH_2)_3N_3}-]_n[-O-SiMe_2-]m also undergoes a click reaction with 1 to produce the side chain polyrotaxane. Cyclic voltammograms of these rotaxanes and 1 [(DB24C8)1] show the Fe(ii)/Fe(iii) redox at the same potential, but with different current depending on their molecular weights. Addition of PdCl_2(MeCN)_2 to a solution of the side-chain polyrotaxane forms gel which regenerates the sol upon addition of PPh_3.