NEXAFS Chemical State and Bond Lengths of p-Aminobenzoic Acid in Solution and Solid State
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Published version
Author(s)
Type
Conference Paper
Abstract
Nitrogen K-edge XPS and NEXAFS of the two polymorphic forms of para-
aminobenzoic acid (PABA) are significantly different reflecting variation in hydrogen bonding.
Alteration in hydrogen bonding at the amino group leads to a shift to high energy for both the
XPS N 1s core level and the 3
p
* NEXAFS resonance with
b
-PABA. Participation of the amine
group in the aromatic system causes the 1
p
* resonance to be sensitive to the nature of the
intermolecular bonding at the
para
-carboxylic acid group, and a shift to low energy for
a
-
PABA is observed due to hydrogen-bonded carboxylic acid dimer formation. FEFF
calculations also successfully reproduce both the energy and intensity variations observed for
the
s
* shape resonance associated with the C
-
N bond, with the majority of the decrease in
energy observed for
b
-PABA arising from the longer C
-
N bond.
aminobenzoic acid (PABA) are significantly different reflecting variation in hydrogen bonding.
Alteration in hydrogen bonding at the amino group leads to a shift to high energy for both the
XPS N 1s core level and the 3
p
* NEXAFS resonance with
b
-PABA. Participation of the amine
group in the aromatic system causes the 1
p
* resonance to be sensitive to the nature of the
intermolecular bonding at the
para
-carboxylic acid group, and a shift to low energy for
a
-
PABA is observed due to hydrogen-bonded carboxylic acid dimer formation. FEFF
calculations also successfully reproduce both the energy and intensity variations observed for
the
s
* shape resonance associated with the C
-
N bond, with the majority of the decrease in
energy observed for
b
-PABA arising from the longer C
-
N bond.
Date Issued
2016-06-06
Date Acceptance
2015-12-15
Citation
Journal of Physics: Conference Series, 2016, 712
ISSN
1742-6588
Publisher
IOP Publishing: Conference Series
Journal / Book Title
Journal of Physics: Conference Series
Volume
712
Copyright Statement
© 2016 The Authors. Content from this work may be used under the terms of the
Creative Commons Attribution 3.0 licence. Any further distribution
of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Published under licence by IOP Publishing Ltd
Creative Commons Attribution 3.0 licence. Any further distribution
of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Published under licence by IOP Publishing Ltd
Source
16th International Conference on X-ray Absorption Fine Structure (XAFS16)
Subjects
02 Physical Sciences
09 Engineering
Publication Status
Published
Start Date
2015-08-23
Finish Date
2015-08-28
Coverage Spatial
Karlsruhe, Germany