A homochiral metal-organic framework with amino-functionalized pores

A new metal-organic framework [Zn-2(Cam)(2)(apyr) superset of 2DMF], 4 (apyr = 2-aminopyrazine) has been synthesized by the high temperature equimolar reactions of zinc nitrate with the (+)-camphoric acid (H(2)Cam) in neat DMF solution. The crystal structure of 4 was determined by X-ray analyses and found to be a porous cubic network composed of linked zinc camphorate "paddlewheel'' secondary building units and apyr pillars. The apyr pillars give amino-functionality to the pores. The extended structure of 4 contains guest DMF molecules trapped within the channels. Compound 4 is potentially porous and thermogravimetric analysis is consistent with the initial loss of guest DMF between 75 and 190 degrees C, with the decomposition of the material at 430 degrees C. The material was found to take up racemic alcohols into its pores, however no enantioselectivity was achieved. Reactivity studies of 4 with acetaldehyde show that the amino groups in the pores can be transformed into imine functionalities via post-synthetic covalent modification.