From Sergeants and Soldiers to Chiral Conflict Effects in Helical Polymers by Acting on the Conformational Composition of the Comonomers

Abstract

Different communication mechanisms can be switched within a copolymer by acting on the conformational composition of the components and their chirality. Thus, a Sergeant and Soldiers effect is produced in two diastereomeric copolymer series —poly[( S )‐ 1 r ‐ co ‐( S )‐ 2 ( 1‐r ) ] and poly[( R )‐ 1 r ‐ co ‐( S )‐ 2 ( 1‐r ) ]— due to the presence in chloroform of a preferred conformation in ( S )‐ 2 , and a conformational equilibrium in 1 , where a P helix is induced independently of the absolute configuration of the Soldier. In THF, the presence of a conformational equilibrium at the pendants of the two components produces a reciprocal chiral enhancement effect by copolymerization of the two monomers, while in DMF, a third chiral to chiral communication switch is produced due to the presence of a single conformer at the pendant group of the two components. In such case, a Chiral Conflict or Chiral Accord effect is produced depending if the two components induce the same or the opposite helical sense