title: Communication: Physical origins of ionization potential shifts in mixed carboxylic acids and water complexes.
abstract: The ionization potential (IP) of the aromatic alpha hydroxy carboxylic acid, 9-hydroxy-9-fluorene carboxylic acid (9HFCA), is shifted by complexation with hydrogen bonding ligands such as water and formic acid. Generalized Kohn-Sham energy decomposition analysis decomposes the intermolecular binding energies into a frozen energy term, polarization, correlation, and/or dispersion energy terms, as well as terms of geometric relaxation and zero point energy. We observe that in each dimer the attractive polarization always increases upon ionization, enhancing binding in the cation and shifting the IP toward the red. For 9HFCA-H2O, a substantial decrease of the repulsive frozen energy in cation further shifts the IP toward red. For 9HFCA-HCOOH, the increase of the frozen energy actually occurs in the cation and shifts the IP toward blue. Consistent with the experimental measurements, our analysis provides new, non-intuitive perspectives on multiple hydrogen bonds interactions in carboxylic acids and water complexes.
authors: School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan 453003, China.
authors: Quanli
authors: Q
authors: Gu
authors: The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
authors: Zhen
authors: Z
authors: Tang
authors: The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
authors: Peifeng
authors: P
authors: Su
authors: The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
authors: Wei
authors: W
authors: Wu
authors: School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan 453003, China.
authors: Zhijun
authors: Z
authors: Yang
authors: Chemistry Department, University of Virginia, Charlottesville, Virginia 22904, USA.
authors: Carl O
authors: CO
authors: Trindle
authors: Chemistry Department, Wesleyan University, Middletown, Connecticut 06459, USA.
authors: Joseph L
authors: JL
authors: Knee