Directed one-pot syntheses of crown ether wheel-containing main chain-type polyrotaxanes with controlled rotaxanation ratios.

The directed synthesis of main chain-type polyrotaxanes possessing crown ether wheels was successfully achieved through two methods, A and B. Method A involved the direct wheel threading of poly(sec-ammonium salt) followed by end-capping with a bulky group, while method B utilized polyaddition of a pseudo[2]rotaxane monomer to facilitate the control of the structure, i.e. the rotaxanation ratio.

Aromatic hydrocarbon-catalyzed direct reaction of sulfur and sodium in a heterogeneous system: selective and facile synthesis of sodium monosulfide and disulfide.

Sodium disulfide and monosulfide were selectively formed via the direct reaction of sulfur and an equimolar amount of sodium in 1,2-dimethoxyethane at 70 degrees C in the presence of a catalytic amount of aromatic hydrocarbons and ketone.