fedasa dereje - Academia.edu (original) (raw)

my name is dereje fedasa. I am lecturer at injibara university. I graduate my b.sc from dire dawa university and I graduated m.sc from wollega university.

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Research paper thumbnail of Effect of Substituents on Electronic Structure and Photophysical Properties of Re(I)(CO)<sub>3</sub>Cl(R-2, 2’-Bipyridine) Complex: DFT/TDDFT Study

International journal of computational and theoretical chemistry, 2020

The electronic structure, absorption and emission spectra, as well as phosphorescence efficiency ... more The electronic structure, absorption and emission spectra, as well as phosphorescence efficiency of Re(I) tricarbonyl complexes of a general formula fac-[Re(I)(CO) 3 (L)(R-N^N)](L = Cl; N^N = 2, 2'-bipyridine; R =-H, 1;-NO 2 , 2;-PhNO 2 , 3;-NH 2 , 4;-TPA (triphenylamine), 5) were investigated by using density functional theory(DFT) and time dependents density functional theory (TDDFT) methods. The calculated results reveal that introductions of the Electron with drawing group (EWG) and Electron donating group (EDG) on the R position of 2, 2'-bipyridine ligand. When EWG (-NO 2 and-PhNO 2) are introduced into complex 2 and 3, the lowest energy absorption and emission bands are red shifted compared with that of complex 1. On the contrary, the introduction of the EDG (-NH 2 and-TPA) in complex 4 and 5 cause corresponding blue shifted. The solvent effect on absorption and emission spectrum indicates that the lowest energy absorption and emission bands have red shifts with the decrease of solvent polarity. The electronic affinity (EA), ionization potential (IP) and reorganization energy (λ) results show that complex 5 is suitable to be used as an emitter in phosphorescence organic light emitting diodes (PHOLEDs). Meanwhile the emission quantum yield of complex 5 is possibly higher than that of other complexes.

Research paper thumbnail of Effect of Substituents on the Electronic Structure and Degradation Process in Carbazole Derivatives for Blue OLED Host Materials

Chemistry of Materials, 2016

Research paper thumbnail of Effect of Substituents on Electronic Structure and Photophysical Properties of Re(I)(CO) 3 Cl(R-2, 2'-Bipyridine) Complex: DFT/TDDFT Study

0riginal article, 2020

To cite this article: Dereje Fedasa, Dunkana Negussa, Alemu Talema. Effect of Substituents on Ele... more To cite this article: Dereje Fedasa, Dunkana Negussa, Alemu Talema. Effect of Substituents on Electronic Structure and Photophysical Properties of Re(I)(CO) 3 Cl(R-2, 2'-Bipyridine) Complex: DFT/TDDFT Study. Abstract: The electronic structure, absorption and emission spectra, as well as phosphorescence efficiency of Re(I) tricarbonyl complexes of a general formula fac-[Re(I)(CO) 3 (L)(R-N^N)](L = Cl; N^N = 2, 2'-bipyridine; R =-H, 1;-NO 2 , 2;-PhNO 2 , 3;-NH 2 , 4;-TPA (triphenylamine), 5) were investigated by using density functional theory(DFT) and time dependents density functional theory (TDDFT) methods. The calculated results reveal that introductions of the Electron with drawing group (EWG) and Electron donating group (EDG) on the R position of 2, 2'-bipyridine ligand. When EWG (-NO 2 and-PhNO 2) are introduced into complex 2 and 3, the lowest energy absorption and emission bands are red shifted compared with that of complex 1. On the contrary, the introduction of the EDG (-NH 2 and-TPA) in complex 4 and 5 cause corresponding blue shifted. The solvent effect on absorption and emission spectrum indicates that the lowest energy absorption and emission bands have red shifts with the decrease of solvent polarity. The electronic affinity (EA), ionization potential (IP) and reorganization energy (λ) results show that complex 5 is suitable to be used as an emitter in phosphorescence organic light emitting diodes (PHOLEDs). Meanwhile the emission quantum yield of complex 5 is possibly higher than that of other complexes.

Research paper thumbnail of Effect of Substituents on Electronic Structure and Photophysical Properties of Re(I)(CO)<sub>3</sub>Cl(R-2, 2’-Bipyridine) Complex: DFT/TDDFT Study

International journal of computational and theoretical chemistry, 2020

The electronic structure, absorption and emission spectra, as well as phosphorescence efficiency ... more The electronic structure, absorption and emission spectra, as well as phosphorescence efficiency of Re(I) tricarbonyl complexes of a general formula fac-[Re(I)(CO) 3 (L)(R-N^N)](L = Cl; N^N = 2, 2'-bipyridine; R =-H, 1;-NO 2 , 2;-PhNO 2 , 3;-NH 2 , 4;-TPA (triphenylamine), 5) were investigated by using density functional theory(DFT) and time dependents density functional theory (TDDFT) methods. The calculated results reveal that introductions of the Electron with drawing group (EWG) and Electron donating group (EDG) on the R position of 2, 2'-bipyridine ligand. When EWG (-NO 2 and-PhNO 2) are introduced into complex 2 and 3, the lowest energy absorption and emission bands are red shifted compared with that of complex 1. On the contrary, the introduction of the EDG (-NH 2 and-TPA) in complex 4 and 5 cause corresponding blue shifted. The solvent effect on absorption and emission spectrum indicates that the lowest energy absorption and emission bands have red shifts with the decrease of solvent polarity. The electronic affinity (EA), ionization potential (IP) and reorganization energy (λ) results show that complex 5 is suitable to be used as an emitter in phosphorescence organic light emitting diodes (PHOLEDs). Meanwhile the emission quantum yield of complex 5 is possibly higher than that of other complexes.

Research paper thumbnail of Effect of Substituents on the Electronic Structure and Degradation Process in Carbazole Derivatives for Blue OLED Host Materials

Chemistry of Materials, 2016

Research paper thumbnail of Effect of Substituents on Electronic Structure and Photophysical Properties of Re(I)(CO) 3 Cl(R-2, 2'-Bipyridine) Complex: DFT/TDDFT Study

0riginal article, 2020

To cite this article: Dereje Fedasa, Dunkana Negussa, Alemu Talema. Effect of Substituents on Ele... more To cite this article: Dereje Fedasa, Dunkana Negussa, Alemu Talema. Effect of Substituents on Electronic Structure and Photophysical Properties of Re(I)(CO) 3 Cl(R-2, 2'-Bipyridine) Complex: DFT/TDDFT Study. Abstract: The electronic structure, absorption and emission spectra, as well as phosphorescence efficiency of Re(I) tricarbonyl complexes of a general formula fac-[Re(I)(CO) 3 (L)(R-N^N)](L = Cl; N^N = 2, 2'-bipyridine; R =-H, 1;-NO 2 , 2;-PhNO 2 , 3;-NH 2 , 4;-TPA (triphenylamine), 5) were investigated by using density functional theory(DFT) and time dependents density functional theory (TDDFT) methods. The calculated results reveal that introductions of the Electron with drawing group (EWG) and Electron donating group (EDG) on the R position of 2, 2'-bipyridine ligand. When EWG (-NO 2 and-PhNO 2) are introduced into complex 2 and 3, the lowest energy absorption and emission bands are red shifted compared with that of complex 1. On the contrary, the introduction of the EDG (-NH 2 and-TPA) in complex 4 and 5 cause corresponding blue shifted. The solvent effect on absorption and emission spectrum indicates that the lowest energy absorption and emission bands have red shifts with the decrease of solvent polarity. The electronic affinity (EA), ionization potential (IP) and reorganization energy (λ) results show that complex 5 is suitable to be used as an emitter in phosphorescence organic light emitting diodes (PHOLEDs). Meanwhile the emission quantum yield of complex 5 is possibly higher than that of other complexes.

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