Synthesis of chiral periodic mesoporous silicas (ChiMO) of MCM-41 type with binaphthyl and cyclohexadiyl groups incorporated in the framework and direct measurement of their optical activity

A series of periodic mesoporous silicas of MCM-41 type containing varying amounts (550%) of chiral binaphthyl and cyclohexadiyl moieties occupying framework positions have been synthesized, and their characteristic MCM-41 features were observed by powder XRD and porosity measurements. The covalent bonding of the organics to the silicate framework was confirmed by H-1 and Si-29 MAS NMR experiments. Direct measurement of the optical activity demonstrates that the solids are able to rotate the angle of plane-polarized light. Also, a certain degree of chiral discrimination has been observed for the asymmetric enhancement of the binaphthyl fluorescence by adding enantiomerically pure 1,2-cyclohexadiamine.