Statistical Ring Catenation under Thermodynamic Control: Should the Jacobson-Stockmayer Cyclization Theory Take into Account Catenane Formation?

摘要: An extension of the Jacobson–Stockmayer theory is presented to include reversible formation [2]catenanes in a ring–chain system under thermodynamic control. The extended based on molar catenation constant, measuring ease two ring oligomers, whose expression was obtained previous work. Two scenarios have been considered: that “thick” (hydrocarbon-like) chains and “thin” (DNA-like) chains. In case chains, catenanes can be neglected, unless unlikely very large value equilibrium constant for linear propagation (K ≈ 108 mol–1 L, or larger). For K tending infinity, becomes chain-free where only ring–catenane equilibria occur. Under this condition, there critical concentration below which rings are present at above fraction remains excess monomer converted into catenanes. format...