L- and D-proline adsorption by chiral ordered mesoporous silica

Langmuir. 2012 Apr 24;28(16):6638-44. doi: 10.1021/la300864n. Epub 2012 Apr 13.

Abstract

Chiral ordered mesoporous silica (COMS) was synthesized in the presence of amino acid proline by combining tetraethyl orthosilicate and quaternized aminosilane silica sources. The as-prepared materials were activated by calcination or microwave chemical extraction to remove the organic templates. The powder X-ray diffraction and N2 adsorption characterization revealed in COMS the structural and textural features of MCM-41-type silica. The chirality of the material was disclosed by mixed and separate L- and D-proline adsorption on the COMS prepared with L-proline (L-Pro-COMS) and D-proline (d-Pro-COMS). It was found that the maximum L-proline and D-proline adsorption capacities on L-Pro-COMS were ca. 2.3 and 0.6 mmol/g, respectively, while the adsorption of D-proline was higher than that of l-proline on d-Pro-COMS. Finally, both activation routes yielded enantioselective silicas able to separate proline racemate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Molecular Structure
  • Particle Size
  • Porosity
  • Proline / chemistry*
  • Silicon Dioxide / chemistry*
  • Stereoisomerism
  • Surface Properties

Substances

  • Silicon Dioxide
  • Proline