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Reactivity of Azole Anions with CO 2 from the DFT Perspective
Author(s) -
Tang Huarong,
Wu Chao
Publication year - 2013
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201200986
Subject(s) - chemistry , azole , density functional theory , absorption (acoustics) , computational chemistry , adsorption , natural bond orbital , inorganic chemistry , materials science , antifungal , medicine , dermatology , composite material
Azole anions are key components in CO 2 capture materials that include ionic liquids and porous solids. Herein, we use density functional theory (DFT) and a Langmuir‐type adsorption model to study azole anion–CO 2 interactions. Linear CO 2 has to be bent by approximately 45° to form an NC bond within the azole ring. The energy cost of bending renders CO 2 absorption much more difficult compared to SO 2 absorption. For different azole anions, the number of nitrogen atoms in the ring and the natural bond orbital energy of the reacting nitrogen lone pair, both linearly correlate with the calculated reaction enthalpy and are useful handles for new sorbent designs. Unlike for SO 2 , the azole parent architecture (unsubstituted) does not allow successive CO 2 absorption under mild conditions (<0.12 MPa and at room temperature). Experimental CO 2 and SO 2 absorption isotherms are reproduced by using the Langmuir model parameterized with the calibrated DFT reaction enthalpies. This study provides insight for designing azole‐based CO 2 ‐capture materials.