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

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.

Anahtar Kelimeler:

4-Florobenzil Alkol, DFT, NBO, Orbital etkileşimleri

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

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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