A terminally protected dipeptide: from crystal structure and self-assembly, through co-assembly with carbon-based materials, to a ternary catalyst for reduction chemistry in water

Soft Matter. 2016 Jan 7;12(1):238-45. doi: 10.1039/c5sm02189h.

Abstract

A terminally protected, hydrophobic dipeptide Boc-L-Cys(Me)-L-Leu-OMe (1) was synthesized and its 3D-structure was determined by single crystal X-ray diffraction analysis. This peptide is able to hierarchically self-assemble in a variety of superstructures, including hollow rods, ranging from the nano- to the macroscale, and organogels. In addition, 1 is able to drive fullerene (C60) or multiwalled carbon nanotubes (MWCNTs) in an organogel by co-assembling with them. A hybrid 1-C60–MWCNT organogel was prepared and converted (through a high vacuum-drying process) into a robust, high-volume, water insoluble, solid material where C60 is well dispersed over the entire superstructure. This ternary material was successfully tested as a catalyst for: (i) the reduction reaction of water-soluble azo compounds mediated by NaBH4 and UV-light with an overall performance remarkably better than that provided by C60 alone, and (ii) the NaBH4-mediated reduction of benzoic acid to benzyl alcohol. Our results suggest that the self-assembly properties of 1 might be related to the occurrence in its single crystal structure of a sixfold screw axis, a feature shared by most of the linear peptides known so far to give rise to nanotubes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzoic Acid / chemistry
  • Benzyl Alcohol / chemistry
  • Borohydrides / chemistry
  • Catalysis
  • Crystallization
  • Cysteine / analogs & derivatives
  • Dipeptides / chemistry*
  • Fullerenes / chemistry*
  • Leucine / analogs & derivatives
  • Nanotubes / chemistry*
  • Oxidation-Reduction

Substances

  • Borohydrides
  • Dipeptides
  • Fullerenes
  • sodium borohydride
  • Benzoic Acid
  • Leucine
  • Cysteine
  • Benzyl Alcohol