Influence of Ring Size on Hydrogen Storage Performance of cis‐Aziridine Derivatives: A Thermodynamic Investigation

ABSTRACT This study investigates the influence of ring size on the hydrogen storage capacity of cis‐aziridine derivatives through a thermodynamic approach. Two N‐cycloalkylated ethyl aziridine‐2‐carboxylates, containing six‐ and seven‐membered rings, were synthesized in a single step via aza‐Michael addition and intramolecular cyclization. Structural characterization was performed using FTIR and 1 H‐NMR. Hydrogen storage performance was evaluated under varying pressures (0–100 bar) at 125°C. Results revealed that the seven‐membered ring derivative achieved 4 wt.% storage capacity, surpassing the six‐membered ring derivative (3.6 wt.%). The findings highlight the structural advantage of larger cyclic systems for enhancing hydrogen uptake, offering valuable insights for the design of efficient hydrogen storage materials.