Porphyrin-based metal organic frameworks: Unusual examples of Mn(II) carboxylate frameworks containing free-base porphyrins

The structures of two porphyrin-based metal-organic frameworks are reported. The reaction of a carb-oxylic acid functionalised porphyrin with Mn(NO3)2givesrise to either a one-dimensional or a two-dimensional fra-mework structure depending on the reaction solvent em-ployed.1(a¼8.3080(5) A ̊,b¼14.4466(10) A ̊,c¼21.8737(14) A ̊,a¼99.182(6),b¼94.118(5),g¼92.562(5),P11,R1¼0.0894,wR2¼0.2850) consistsof one-dimensional coordination polymers linked throughhydrogen-bonded porphyrin molecules leading to a two-dimensional array. In contrast2(a¼13.6852(6) A ̊,b¼41.1655(15) A ̊,c¼15.4535(6) A ̊,b¼109.954(5),P21/c,R1¼0.1218,wR2¼0.3806) consists of two-di-mensional sheets, constructed from dinuclear Mn(II) clus-ters and bridging porphyrin ligands, which, as in1, arelinked through hydrogen-bonded porphyrin molecules butin this case leading to a three-dimensional array. In bothstructures it is notable that the porphyrin molecules do notbind the Mn(II) cations through the macrocyclic carity,rather both structures.