The Ca-MOF FIR-29 is synthesized and exhibits a honeycomb lattice of hexagonal channels with an aperture of similar to 16 angstrom, giving a BET surface area of 2061 m(2) g(-1). The consecutive slipped pi ... pi stacking interactions of photoactive tris((4-carboxyl)phenylduryl)amine (TCPA) groups on the surface of hexagonal channels makes it an effective photocatalyst for catalyzing the typical Mannich photocatalysis, forming beta-tetrahydroisoquinolne ketones in high isolated yields. Catalytic activity for FIR-29 is about 2.7 times enhancement over that for mesoporous DUT-63 consisted of discrete TCPA groups without any intermolecular interaction. This is mainly due to the fact that the rigid compact stacking of tri([1,1'-biphenyl]-4-yl)amine (TBPA) is conducive to form stable TBPA radical, and is optimal for electron or energy transfer to expedite the reactivity of spa carbon atoms and allow higher photocatalytic conversion.