Context <p>The study of molecular stability, electronic properties, and molecular interactions, including topological analysis of 5,10,15,20-tetrakis-(4-carboxyphenyl)porphyrin (TCPP) and its derivatives, holds considerable applications and implications in material science (including sensing applications), human health, and environmental protection. Our work investigates the unique features of metallic TCPP to drive advancements in these related fields. The increase in adsorption energy and decrease in intermolecular distance confirms the efficiency of the protonation and metalation configurations in gas interaction properties and makes them potential for atmospheric monitoring applications. Additionally, we conducted an analysis of non-covalent interactions (NCI), which reveals that the Van-der-Waals (dominating) and steric type interaction occurring between studied molecules. Moreover, by examining the density of states, GCRD properties, and Koopman’s theorem; physisorption behaviour of examined materials with the gases are confirmed. The significant sensing capabilities of ZnTCPP towards C₂N₂ gas confirms the cyanogen recognition, offering a next generation porphyrin-inspired system for environmental surveillance and toxic pollutant remediation.</p> Methods <p>In this study, we performed DFT calculations using B3LYP hybrid functional by implementing ORCA software package. The optimization calculations of TCPP and its derivatives are performed with def2-TZVP triple-zeta basis set. For data analysis and visualization of stability, electronic and interaction properties of optimized configurations, this study employs diverse computational tools. Notably, visualization software Avogadro, molecular interaction analysis software Multiwfn are employed. By utilizing these comprehensive tools, we obtained valuable insights into GCRD properties, electronic and molecular interaction through topological analysis, including QTAIM and RDG-NCI methods.</p>