Zagazig University Digital Repository
Home
Thesis & Publications
All Contents
Publications
Thesis
Graduation Projects
Research Area
Research Area Reports
Search by Research Area
Universities Thesis
ACADEMIC Links
ACADEMIC RESEARCH
Zagazig University Authors
Africa Research Statistics
Google Scholar
Research Gate
Researcher ID
CrossRef
The structure of cinnamic acid and cinnamoyl azides, a unique localized p system: The electronic spectra and DFT-treatment
Faculty
Science
Year:
2012
Type of Publication:
Article
Pages:
1256-1272
Authors:
Abu-Eittah, Rafie H, Khedr, M. K, Goma, M, Zordok, W
DOI:
10.1002/qua.23120
Journal:
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY WILEY-BLACKWELL
Volume:
112
Research Area:
Chemistry; Mathematics; Physics
ISSN
ISI:000299335900003
Keywords :
cinnamic acid and cinnamoyl azides, localized p system, opposing dipoles in cinnamic acid and cinnamoyl azides, unique-disturbed structure of cinnamic acid and cinnamoyl azides
Abstract:
The electronic absorption spectra of cinnamic acid and some cinnamoyl azides have been recorded in absolute methanol and investigated to explore the structure of the titled compounds. Cinnamic acid and its derivatives have a double bond, -C=C-, between the aromatic ring and the carboxyl group which disturbs the p electron system of the molecule and inhibits electron delocalization as compared with styrene or benzoic acid. The azide group is neither a strong electron donor nor a strong electron acceptor but it increases conjugation in the molecule. The observed spectra confirm that each of the cinnamic acid and cinnamoyl azide molecules is one of a kind of unique disturbed p-system and not of different independent p systems, each on a fragment of the molecule as predicted by the quantum theory of atom in molecule calculations. The spectra of cinnamic acid and its derivatives are not the additive spectra of the different fragments of the molecule. The spectra are characterized by few number, low intensity, and high-energy electronic transitions (absorption bands) in the UV-vis region. Molecular orbital calculations confirmed the spectral observations. The optimized geometry of the ground state of the studied compounds is calculated using the DFT/B3LYP/6-31G{*}{*} level of theory and an explicit molecular orbital analysis is carried out. Excited states are calculated using the TD/DFT procedure as implemented by the Gamess 2009 package of programs. The correspondence between calculated and the observed transition energies is adequate. (C) 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Online
PDF
جامعة المنصورة
جامعة الاسكندرية
جامعة القاهرة
جامعة سوهاج
جامعة الفيوم
جامعة بنها
جامعة دمياط
جامعة بورسعيد
جامعة حلوان
جامعة السويس
شراقوة
جامعة المنيا
جامعة دمنهور
جامعة المنوفية
جامعة أسوان
جامعة جنوب الوادى
جامعة قناة السويس
جامعة عين شمس
جامعة أسيوط
جامعة كفر الشيخ
جامعة السادات
جامعة طنطا
جامعة بنى سويف