Donor-pi-akseptör tipi moleküllerin spektroskopik özelliklerinin teorik olarak tespiti ve deneysel sonuçlarla incelenmesi /
Yazar: DİLARA ALTUNKUM
Danışman: PROF. DR. MUSTAFA CAN
İzmir Katip Çelebi Üniversitesi / Fen Bilimleri Enstitüsü / Nanobilim ve Nanoteknoloji Ana Bilim Dalı
Derece: Yüksek Lisans, 2022
Konu: Kimya = Chemistry
Dizin: Donörler = Donors ; Organik moleküller = Organic molekules ; Yoğunluk fonksiyonu teorisi = Density function theory

Özet:
Kuramsal hesaplar; kimyasal bir yapının geometrik, elektronik ve kimyasal özellikleri hakkında bilgi edinmek için sıklıkla kullanılan araçlardan biridir. Farklı yöntemler ve yaklaşımlar içeren bu hesaplar; yapının sentezi, analizi veya aygıtın üretiminden önce fikir edinmek için kullanılabilmektedir. Bu hesaplar için yapıya uygun yöntem, yaklaşım ve baz seti gibi parametrelerin tespiti ise yüksek önem taşımaktadır.
Çalışmada 3-(4-(bis(4-(hegziloksi)fenil)amino)fenil)-2-siyanoakrilik asit (MC-32) molekülünün kuramsal hesapları yürütülecek, elde edilen sonuçlar ise molekülün aydınlatılması ve deneysel çalışmalara yol göstermesi için kullanılacaktır.

Anahtar Sözcükler: Yoğunluk fonksiyonel teori, Hesaplamalı Kimya, Organik Molekü

Abstract:
Theoretical calculation is one of the frequently used methods to obtain information about the geometric, electronic and chemical properties of a chemical structure. These calculations which are include different methods and approaches can be used to get an idea before the synthesis, analysis of the structure or the production of devices. For this kind of calculation, it is crucial to determine the parameters such as method, approach and a suitable basis set for the structure. In this thesis, experimental and theoretical calculation of 3-(4-(bis(4-(hexyloxy)amino)phenyl)-2-
cyanoacrylic acid (MC32) and 3-[7-(4-{bis[4-(hexyloxy)phenyl]amino}phenyl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl]-2cyanoacetic (MC48) molecules, whose synthesis was done before, were carried out. The obtained results will be used to shed light on the molecules and to guide experiment studies. Experimental and theoretical studies of UV-vis, cyclic voltammetry and NMR (1H-NMR) of donoracceptor type molecules were carried out. Theoretically, the 6-311G(d,p) basis set
from the DFT/B3LYP method was used. While the experimental UV graphics of the molecules were examined, the maximum
absorption peak values of the MC32 were observed at 415 nm. Similarly, the maximum absorption peaks for molecule of MC48 were found at the 500 nm. According to the theoretical results, the absorption peaks of MC32 and MC48 were calculated as 375 nm and 445 nm, respectively. The oxidation/reduction potentials of MC32/ MC48 have been found at 0.86/-1,38 V
and 0,76/-1,33 V (vs. NHE), while HOMO and LUMO levels have been calculated as 5.26/5.16 eV and 3.02/3.07 eV, respectively. Oxidation potential of MC48 is decreased by the addition of EDOT group (pi group) resulted an increased HOMO level value of the MC48 dye. According to the results of cyclic voltammetry, HOMO/LUMO level of the molecules were calculated as -5.26/-3.02 eV for MC32 and -5.16/-3,07 eV for MC48. As a results of theoretical calculation, the HOMO/LUMO level of molecules were found as -5.36/-2.27 eV and -5,12/-2.58 eV for MC32 and MC48, respectively. The geometric parameters of the MC32 and MC48 molecules, namely bond length and bond angles, were calculated using the 6-311G(d,p) base set in the DFT/B3LYP method. In addition, the Mulliken atomic charges of our synthesized molecules were
calculated by the same method. In this thesis, experimental and theoretical comparisons of MC32 and MC48 molecules were examined and the similar results were obtained.

Keywords: Density functional theory, computational chemistry, organic molecul