NEXAFS Chemical State and Bond Lengths of p-Aminobenzoic Acid in Solution and Solid State

16th International Conference on X-ray Absorption Fine Structure

Stevens, J.S.^1 ; Gainar, A.^1 ; Suljoti, E.^2 ; Xiao, J.^2 ; Golnak, R.^2 ; Aziz, E.F.^2,3 ; Schroeder, S.L.M.^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, 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;    Chemical environment;    Chemical species;    Direct observations;    Length determination;    Local environments;    P-aminobenzoic acid;    Shape resonance;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012136/pdf
DOI  :  10.1088/1742-6596/712/1/012136

来源: IOP

【 摘 要 】

Solid-state and solution pH-dependent NEXAFS studies allow direct observation of the electronic state of para-aminobenzoic acid (PABA) as a function of its chemical environment, revealing the chemical state and bonding of the chemical species. Variations in the ionization potential (IP) and 1s→π∗ resonances unequivocally identify the chemical species (neutral, cationic, or anionic) present and the varying local environment. Shifts in σ∗ shape resonances relative to the IP in the NEXAFS spectra vary with C-N bond length, and the important effect of minor alterations in bond length is confirmed with nitrogen FEFF calculations, leading to the possibility of bond length determination in solution.