The interaction between a complex porphyrin-like system formed by an iron atom and multivacant graphene layer and O-2, CO and CO2 molecules is studied, using Density Functional Theory (DFT) calculations. The multivacancy graphene system used for this study, consists in the removal of a 1,4-dimethybenzene-like moiety, in a 6 x 6 supercell. This removal and the structural optimization subsequently performed, yield to a biaxial vacancy, where the location of an iron atom embedded in it, lead to a system with resemblance to iron-porphyrin systems. This similar structure could be used to form complexes where gas molecules are allowed to interact with these iron-octavacant graphene systems. The study focuses on the structure of the system and the net magnetic moment for different gas molecules: O-2, CO2 and CO. Rippling in the vacant graphene is enhanced through this interaction. (C) 2017 Elsevier B.V. All rights reserved.