4-Florobenzil Alkolün Konformasyon ve Orbital Etkileşimlerinin DFT Metodu ile Teorik Çalışması

Year 2019, Volume: 23 Issue: 3, 797 - 804, 25.12.2019

Nihal Kuş Saliha Ilıcan

https://doi.org/10.19113/sdufenbed.544859

Abstract

Bu
çalışmada, 4-florobenzil alkol (4FBA) molekülünün konformasyonları
DFT/B3LYP/6-311++G(d,p) metodu kullanılarak çalışılmıştır. Bileşiğin optimize
edilmiş geometrisi ve enerjileri belirlenmiştir. 4FBA, minimum enerjili ve
kararlı yapıda iki konformasyona (4FBA-I ve 4FAB-II) sahiptir. İki konformasyon
arasındaki bağıl elektronik enerji değeri 3,6 kJ mol^-1 olarak
hesaplanmıştır. Bariyer enerjisi 2,49 kJ mol^-1 gibi çok küçük bir
değer olarak hesaplanmıştır. Bu durum, konformasyonel bir gevşemeye neden
olarak, en kararlı duruma geçişi sağlayabilir. 4FBA-I ve 4FBA-II formlarının
stabilizasyon enerjileri ve donör-akseptör etkileşimleri doğal bağ orbital
(NBO) analizi ile yapılmıştır. NBO etkileşimlerinin yanında benzen halkasının
karbon atomları üzerinden elektronik delokalizasyonun olduğu gözlenmiştir. Bu
durum, p→p* orbital
etkileşimi ile açıklanabilir. Ayrıca, molekülün en yüksek dolu moleküler
orbitali (HOMO) ve en düşük boş moleküler orbitali (LUMO) arasındaki enerji
farkı hesaplanmış, 4FBA-I ve 4FBA-II için sırasıyla 6,038 ve 6,142 eV olarak
bulunmuştur.

Keywords

4-Florobenzil Alkol, DFT, NBO, Orbital etkileşimleri

Theoretical Study of Conformational and Orbital Interactions of 4-Fluorobenzyl Alcohol by DFT Method

Abstract

In this study, the conformations of 4-fluorobenzyl
alcohol (4FBA) molecule were studied by using DFT/B3LYP/6-311++G(d,p) method.
Optimized geometry and energies of compound were determined. 4FBA has two
conformers (4FBA-I and 4FAB-II) with minimal energies and stable structures.
The difference relative electronic energy of the two conformers were calculated
about 3.6 kJ mol^-1. Barrier energy was calculated as a very small
value (2,49 kJ mol^-1). This may cause conformational relaxation to
the most stable conformer. The stabilization energies and donor-acceptor
interactions of the 4FBA-I and 4FBA-II formations were performed by natural bond
orbital (NBO) analysis. Besides to NBO
interactions, electronic delocalization was observed over carbon atoms of the
benzene ring, and this can be explained by p→p* orbital
interaction. In addition, the energy difference between the highest occupied
molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) was
calculated and found to be 6.038 and 6.142 eV for 4FBA-I and 4FBA-II,
respectively.

Keywords

4-Fluorobenzyl alcohol, DFT, NBO, Orbital interactions

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