The Structure of p-Aminobenzoic Acid in Water: Studies Combining UV-Vis, NEXAFS and RIXS Spectroscopies

16th International Conference on X-ray Absorption Fine Structure

Gainar, A.^1 ; Stevens, J.S.^1 ; Suljoti, E.^2 ; Xiao, J.^2 ; Golnak, R.^2 ; Aziz, E.F.^2,3 ; Schroeder, S.L.M.^1,4,5

School of Chemical Engineering and Analytical Science, University of Manchester, Oxford Road, Manchester

M13 9PL, United Kingdom^1

Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq), Helmholtz- Zentrum Berlin für Materialien und Energie Institution, Albert Einstein Strasse 15, Berlin

12489, Germany^2

Freie Universität Berlin, Arnimallee 14, Berlin

14195, Germany^3

School of Chemical and Process Engineering, University of Leeds, Leeds

LS2 9JT, United Kingdom^4

DIAMOND Light Source Ltd, Chilton, Didcot

OX11 0QX, United Kingdom^5

关键词: Aminobenzoic acid;    Cationic forms;    Electronic structure calculations;    Electronic transition;    Nonionic;    P-aminobenzoic acid;    UV-Vis absorption spectroscopy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012034/pdf
DOI  :  10.1088/1742-6596/712/1/012034

来源: IOP

【 摘 要 】

NEXAFS-RIXS and home laboratory-based UV-Vis absorption spectroscopy are combined to examine the speciation and electronic structure of para-aminobenzoic acid (PABA) in aqueous solution as a function of pH. DFT and TD-DFT electronic structure calculations reproduce the experimental trends and provide a correlation between the experimental HOMO↔LUMO gap as well as the electronic transitions between molecular orbitals in the non-ionic, anionic and cationic forms of PABA.