A New Metal Carboxylate Framework Based on Porphyrin with Extended π‐Conjugation

We have designed a new tetracarboxylporphyrin building block, ZnTCPEP‐H4, and used it in the construction of a novel porphyrin‐based metal carboxylate framework, [Zn4(μ3‐OH)2(H2O)2(ZnTCPEP‐H)2(DABCO)]·2DMF·10.5H2O(Zn4·ZnTCPEP·DABCO). The framework forms a 3D network linked by tetranuclear Zn cluster nodes {Zn4(μ3‐OH)2(H2O)2}, ZnTCPEP‐H4, and DABCO. The ZnTCPEP‐H4 building block exhibits extended π‐conjugation from the porphyrin core to the terminal carboxyl groups via ethynyl linkers attached to the porphyrin core. The Zn4·ZnTCPEP·DABCO framework gives rise to a 3D porous structure containing open channels with cross sections of approximately 10 × 10 and 7 × 7 Å. It has a BET surface area of 461 m2/g and a Langmuir surface area of 581 m2/g. A hydrogen adsorption capacity of 0.86 wt.‐% was determined for Zn4·ZnTCPEP·DABCO at 77 K and 0.1 MPa.