Polyyne Rotaxanes: Stabilization by Encapsulation.

ABSTRACT: Active metal template Glaser coupling has been used to synthesize a series of rotaxanes consisting of a polyyne, with up to 24 contiguous sp-hybridized carbon atoms, threaded through a variety of macrocycles. Cadiot-Chodkiewicz cross-coupling affords higher yields of rotaxanes than homocoupling. This methodology has been used to prepare [3]rotaxanes with two polyyne chains locked through the same macrocycle. The crystal structure of one of these [3]rotaxanes shows that there is extremely close contact between the central carbon atoms of the threaded hexayne chains (C···C distance 3.29 Å vs 3.4 Å for the sum of van der Waals radii) and that the bond-length-alternation is perturbed in the vicinity of this contact. However, despite the close interaction between the hexayne chains, the [3]rota

SUBMITTER: Movsisyan LD 

PROVIDER: S-EPMC4772075 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature