Inspired by the synthesis of chiral molecular solid material using an optically pure metal complex as the template, researchers from Nanyang Technological University, Singapore, and Jilin University, China, have proposed that the chirality of the metal complex could also be transferred to mesoporous silica matrix.

Testing the idea

A chiral cobalt complex (Λ-[Co(+)(chxn)3]I3) was introduced to the synthesis of mesoporous silica materials with various structures and pore diameters including MCM-41, SBA-15 and SBA-16. The team was delighted to find that enantiomers of the chiral drug (metoprolol) exhibited different release rates when these materials were used as carriers, which implied the formation of a chiral environment in the mesoporous silica matrix.

Subsequent characterization using vibrational circular dichroism (VCD) spectroscopy revealed that the chiral entities of these chiral mesoporous silica materials can be assigned to the building blocks of silica, namely chirally distorted SiO4 tetrahedrons or Si(OSi)4.

The study offers a new protocol for the synthesis of chiral mesoporous materials. The chirality and porosity of these pure silica materials could be exploited in many fields such as asymmetric discrimination, chiral drug delivery and enantio-catalysis.

The researchers presented their work in Nanotechnology.