Expanding the registry of aromatic amide foldamers: folding, photochemistry and assembly using diaza-anthracene units

J Org Chem. 2008 Apr 4;73(7):2687-94. doi: 10.1021/jo702602w. Epub 2008 Mar 11.

Abstract

The synthesis of various 1,8-diaza-4,5-dialkoxy-2,7-anthracene dicarboxylic acid derivatives and their incorporation into cyclic and helically folded aromatic oligoamides are reported. The ability of the diaza-anthracene monomers to undergo photoaddition or head-to-tail photodimerization was investigated in the solid state and in solution. Quantitative conversion of a monomer diester to the corresponding head-to-tail photodimer could be achieved in the solid state without protection from oxygen. The formation of an emissive excimer between two diaza-anthracene units appended at the end of a helically folded oligomer was demonstrated. Intramolecular photodimerization was not observed in this compound, possibly due to the low thermal stability of the head-to-head photoadduct. A cyclic oligoamide composed of two diaza-anthracene and two pyridine units was shown to adopt a flat conformation and to form columnar stacks in the solid state. Longer, noncyclic oligoamides composed of one or two diaza-anthracene units were shown to adopt helical conformations that exist preferentially as double helical dimers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amides / chemistry*
  • Anthracenes / chemical synthesis*
  • Anthracenes / chemistry
  • Anthracenes / radiation effects
  • Crystallography, X-Ray
  • Cyclization
  • Dicarboxylic Acids / chemical synthesis*
  • Dicarboxylic Acids / chemistry
  • Dicarboxylic Acids / radiation effects
  • Models, Molecular
  • Molecular Conformation
  • Molecular Structure
  • Photochemistry
  • Stereoisomerism
  • Ultraviolet Rays

Substances

  • Amides
  • Anthracenes
  • Dicarboxylic Acids