The Spectroscopic Analysis of 2,4'-Dibromoacetophenone Moleculeby Using Quantum Chemical Calculations

Abstract

A spectroscopic investigation, used quantum chemical calculations, of 2,4'-dibromoacetophenone (2,4'-DBrA) molecule have been obtained in this paper. The calculations were supported the experimental results by IR, 1 H and 13 C NMR techniques. Geometrical parameters and optimized energies of 2,4'-DBrA molecule were performed by density functional theory (DFT) B3LYP method 6-311++G(d,p) basis sets. After the geometry optimization of 2,4'-DBrA the vibrational spectra were obtained for this structure. The fundamental vibrations were assigned to base on potential energy distribution (PED) of the vibrational modes by using VEDA 4 (Vibrational Energy Distribution Analysis) program. Density of states for total (TDOS), partial (PDOS) and also overlap population (OPDOS) analysis were obtained. 1 H and 13 C NMR chemical shifts were recorded by using the gauge-invariant atomic orbital (GIAO) method. Besides, electronic properties, such as HOMO and LUMO energies, were performed by time-dependent density functional theory (TD-DFT). Also, molecular electrostatic potential surface (MEPs) and thermodynamic properties were calculated for title molecule. The results are showed consistent with the obtained experimental results.

Determination of the Structures of m- and p-nitro Bromoacetophenone Compounds by Experimental (FT‒IR, NMR) and theoretical approaches

“…2Br3NA için hesaplanan dipol moment (μ), ortalama kutuplanabilirlik (α), yönelime bağlı kutuplanabilirlik (Δα) ve toplam yüksek mertebe kutuplanabilirlik (βtop) değerleri sırasıyla 6.23 Debye, Bu sonuçları hem üre molekülünün değerleriyle (1.52 Debye, 5.04x10 -24 esu, 9.86x10 -24 esu ve 0.78x10 -30 cm 5 /esu) hem de aynı baz setiyle hesaplanan benzer molekülle (Köse, 2016) karşılaştırdığımızda, bileşiklerin doğrusal olmayan optik özellik gösterebileceği değerlendirilmektedir.…”

Comparative Experimental and Theoretical Study on the Structure of Potassium 2,4-Hexadienoate: Structure-Activity Relationship

“…Since, the vibrational frequencies were calculated in the gas phase and the experimental values were obtained in solid phase, a difference was noticed between the theoretical and experimental frequencies, more precisely at high frequencies (above 1500 cm -1 ). The high theoretical frequencies were therefore multiplied by a scaling factor to better fit the experimental results, this method has been frequently used by several researchers namelyJamrózet al (Jamróz & Dobrowolski, 2001),Kose (Kose, 2016)andSert et al (Sert et al, 2015), (Sert, Singer, et al, 2014). The experimental FT-IR spectrum of the potassium sorbate was compared to the theoretical spectra and represented in Figure 2, Figure 3 and Figure 4 as well as the correlation graph that describes the agreement between the computed and experimental wavenumbers.…”