Unveiling the Obscure Potential of o‐carborane Based IFLPs for CO2 Sequestration

Abstract Sequestering carbon dioxide (CO 2 ) from the atmosphere is necessary to achieve a sustainable environment. However, the thermodynamic stability of the CO 2 molecule poses a significant challenge to its capture, necessitating catalysts that can overcome this stability. The emergence of frustrated Lewis pairs (FLPs) has opened a new dimension in the development of organocatalysts for CO 2 capture and utilization. To date, various FLPs have been developed for CO 2 sequestration, yet the quest for robust FLPs continues. Based on the intriguing electronic effects of the carborane polyhedral, o ‐carboranes can be projected as a versatile bridging unit for intramolecular FLPs (IFLPs). In the present work, o ‐carborane based IFLPs i. e., 1‐Al(CH 3 ) 2 –2‐P(CH 3 ) 2 –1,2‐C2B 10 H 10 , 1‐B(CH 3 ) 2 –2‐P(CH 3 ) 2 –1,2‐C 2 B 10 H 10 , 1‐Al(CH 3 ) 2 –2‐N(CH 3 ) 2 –1,2‐C 2 B 10 H 10 , 1‐P(CH 3 ) 2 –2‐B(CH 3 ) 2 –1,2‐C 2 B 10 H 10 abbreviated as AlP, BP, AlN and BN have been proposed for the activation of CO 2 molecule. The density functional theory (DFT) based calculations and thorough orbital analysis have been carried out to extensively study the electronic structure of the o ‐carborane unit. The proposed IFLPs were systematically compared with their corresponding phenyl bridged analogues to assess the effect of o ‐carborane bridging unit on the reactivity of the acidic and basic sites. The results show that the o ‐carborane supported IFLPs are more reactive towards CO 2 than the phenyl bridged IFLPs. Also, placing the basic site on the B atom at the 4 th position of the o ‐carborane bridge rather than the C atom at the 2 nd position results in more reactive IFLPs.