Adenine Tagged Mn-Based Coordination Polymer for Conversion of Carbon Dioxide to Cyclic Carbonates under Atmospheric Pressure

Natural processes collectively balance the global carbon
cycle,
effectively controlling atmospheric carbon dioxide (CO2) levels. However, excessive CO2 emissions due to industrialization
and population growth have disrupted natural processes by increasing
the atmospheric CO2 concentration. To address this issue,
CO2 capture and conversion have been implemented. Metal–organic
frameworks (MOFs)/coordination polymers (CPs) with bioligands, such
as amino acids and nucleobases, are receiving much interest. However,
bio-MOFs are not much reported due to the lack of control over their
coordination with metal ions. In this work, we have developed an adenine-tagged
Mn-CP with dominant basic sites, [Mn(IPT2–)(Ade)(DMF)]n (IPT2– = isophthalate; Ade = adenine; DMF
= N,N′-dimethylformamide).
The analysis of isosteric heat (Qst) of
CO2 adsorption supported the presence of strong interactions
between CO2 and Mn-CP. Mn-CP demonstrated moderate to
outstanding performance in coupling CO2 with smaller and
larger epoxides at ambient pressure under neat conditions. The thermodynamic
activation parameters indicate that Mn-CP operates through an associative
mechanism (ΔS⧧ = −283.4
J mol−1 K−1), with a reduced kinetic
barrier characterized by ΔH⧧ of 17.28 kJ mol–1 and Ea of 20.5 kJ mol–1. The catalytic efficiency of
Mn-CP was particularly notable in the coupling reaction of epichlorohydrin
and CO2, yielding 92% of the corresponding cyclic carbonate
under atmospheric pressure.