Microporous Porphyrin-Based Metal Carboxylate Frameworks with Various Accessible Metal Sites: [Cu2(MDDCPP)] [M=Zn2+, Ni2+, Pd2+, Mn3+(NO3), Ru2+(CO)]

We successfully synthesized a series of porphyrin-based metal carboxylate frameworks with the composition [Cu2(MDDCPP)] [M = Zn2+, Ni2+, Pd2+, Mn3+(NO3), Ru2+(CO)] using MDDCPP [M = Zn2+, Ni2+, Pd2+, Mn3+Cl, Ru2+(CO)] building blocks. Single-crystal X-ray analysis revealed that the framework of [Cu2(ZnDDCPP)] formed a three-dimensional network with (62.82.102)(62.8)2 topology, consisted of a two-component linkage (i.e., paddlewheel Cu2 nodes and ZnDDCPP building blocks), and possessed an internal spherical cavity with a diameter of ca. 20 angstrom. This internal cavity was surrounded by a total of 16 accessible metal sites (AMSs) with two distinct metals, i.e., eight Zn atoms from the ZnDDCPP units and eight Cu atoms from the paddlewheel units. X-ray powder diffraction measurements revealed that five complexes were isostructural regardless of the identity in the central metal of the DDCPP unit, and the diffraction patterns closely matched a pattern simulated from single-crystal data for [Cu2(ZnDDCPP)]. This suggested that a wide variety of AMSs could be incorporated into the framework without alteration of the framework topology. The [Cu2(MDDCPP)] series exhibited permanent porosity, with BET surface areas in the range 379810 m2?g1, and adsorbed between 0.55 and 1.16 wt.-% H2 at 77 K and 0.1 MPa.