Photophysical and Electrochmical Studies of N,N-Bis (2,5-di-tert-butylphenyl) - 3,4,9,10 perylenebis (dicarboximide) (DBPI)

El-Hallag, Ibrahim S.,El-Daly, Samy A. Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.4

The titled dye of DBPI gives amplified spontaneous emission (ASE) with maximum at 580 nm upon pumping by nitrogen laser (${\lambda}_{ex}\;=\;337.1\;nm$). The ground state absorption cross section (${\sigma}_A$) and emission cross section (${\sigma}_E$) as well as effective emission cross section(${\sigma}^*_E$) have been determined. The electronic absorption spectra of DBPI were measured in ethanol and tetrahydrofuran at room and low temperature. DBPI displays molecular aggregation in water. The photochemical reactivity of DBPI was also studied in carbon tetrachloride upon irradiation with 525 nm light. The electrochemical investigation of DBPI dye has been carried out using cyclic voltammetry and convolution deconvolution voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP) in two different solvents acetonitrile ($CH_3CN$) and dimethylformamide (DMF). The species were reduced via consumption of two sequential electrons to form radical anion and dianion (EE mechanism). In switching the potential to positive direction, the compound was oxidized by loss of two sequential electrons, which were followed by a fast dimerization and/or aggregation process i.e $EC_{dim1}EC_{dim2}$ mechanism. The electrode reaction pathway and the chemical and electrochemical parameters of the investigated compound were determined using cyclic and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.

Factors Affecting Nucleation and Growth of Chromium Electrodeposited from Cr³⁺ Electrolytes Based on Deep Eutectic Solvents

El-Hallag, Ibrahim S.,Moharram, Youssef I.,Darweesh, Mona A.,Tartour, Ahmed R. The Korean Electrochemical Society 2020 Journal of electrochemical science and technology Vol.11 No.3

Chromium was electrodeposited from deep eutectic solvents-based Cr³⁺ electrolytes on HB-pencil graphite electrode. Factors influencing the electrochemical behavior and the processes of Cr nucleation and growth were explored using cyclic voltammetry and chronoamperometry techniques, respectively. Cr³⁺ reduction was found to occur through an irreversible diffusion-controlled step followed by another irreversible one of impure diffusional behaviour. The reduction behavior was found to be greatly affected by Cr³⁺ concentration, temperature, and type of hydrogen bond donor used in deep eutectic solvents (DESs) preparation. A more comprehensive model was suggested and successfully applied to extract a consistent data relevant to Cr nucleation kinetics from the experimental current density transients. The potential, the temperature, and the hydrogen bond donor type were estimated to be critical factors controlling Cr nucleation. The nucleation and growth processes of Cr from either choline chloride/ethylene glycol (EG-DES) or choline chloride/urea (U-DES) deep eutectic solvents were evaluated at 70℃ to be three-dimensional (3D) instantaneous and diffusion-controlled, respectively. However, the kinetics of Cr nucleation from EG-DES was found to be faster than that from U-DES. Cr nucleation was tending to be instantaneous at higher temperature, potential, and Cr³⁺ concentration. Cr nuclei electrodeposited from EG-DES were characterized at different conditions using scanning electron microscope (SEM). SEM images show that high number density of fine spherical nuclei of almost same sizes was nearly obtained at higher temperature and more negative potential. Energy dispersive spectroscopy (EDS) analysis confirms that Cr deposits were obtained.

Photophysical Parameters, Photodecomposition, Fluorescence Quenching and Convolutive Voltammetry of 7-Diethylaminocoumarin (DEAC) Laser Dye

El-Daly, S.A.,El-Hallag, I.S. Korean Chemical Society 2010 대한화학회지 Vol.54 No.1

7 diethylaminocoumarin (DEAC) 레이저 염료의 광물리적 특성들을 다양한 용매에서 측정하였다. DEAC의 방출 스펙트럼은 양이온성(CTAC) 미셀과 음이온성(SDS) 미셀에서 측정하였고, 레이저 파라미터는 아세톤, 다이옥산, 에탄올 및 dimethylforamide (DMF)과 같은 여러 가지 용매에 대하여 계산하였다. DEAC의 광반응성은 366 nm 빛을 사용하여 $CCl_4$ 용매에서 연구하였고, 광화학 수득률 (${\Phi}_c$)과 속도 상수(k)도 결정하였다. picric acid (PA), tetracyanoethylene (TCNE), 7,7,8,8-tetracynoquinonedimethane (TCNQ)등의 유기 수용체와 DEAC의 상호 작용에 대한 연구는 acetonitrile ($CH_3CN$) 용액에서 형광을 측정하므로 써 수행하였다. DEAC의 전기화학적 연구는 백금 전극을 사용하여 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP)/$CH_3CN$ 용액에서 순환 전류-전압법, convolutive voltammetry 및 디지털 시뮬레이션을 조합하여 수행하였고, 전기화학 파라미터도 결정하였다. The photophysical properties of 7-diethylaminocoumarin (DEAC) laser dye have been measured in different solvents. The emission spectrum of DEAC has also been measured in cationic (CTAC) and anionic (SDS) micelles. The laser parameters have been calculated in different solvents namely acetone, dioxane, ethanol and dimethylforamide(DMF). The photoreactivity of DEAC has been studied in $CCl_4$ solvent using 366 nm light. The values of photochemical yield (${\Phi}_c$) and rate constant (k) are determined. The interaction of organic acceptors such as picric acid (PA), tetracyanoethylene (TCNE) and 7,7,8,8-tetracynoquinonedimethane (TCNQ) with DEAC are also studied using fluorescence measurements in acetonitrile ($CH_3CN$). The electrochemical investigation of (DEAC) has been carried out using cyclic voltammetry and convolutive voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol $L^{-1}$ tetrabutyl ammonium perchlorate (TBAP) in $CH_3CN$ solvent. The electrochemical parameters of the investigated compound were determined using cyclic and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.

Photophysical and Electrochmical Studies of N,N-Bis (2,5-di-tert-butylphenyl) - 3,4,9,10 perylenebis (dicarboximide) (DBPI)

Ibrahim S. El-Hallag,Samy A. El-Daly 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.4

The titled dye of DBPI gives amplified spontaneous emission (ASE) with maximum at 580 nm upon pumping by nitrogen laser (λex = 337.1 nm). The ground state absorption cross section (σA) and emission cross section (σE) as well as effective emission cross section(σ*E) have been determined. The electronic absorption spectra of DBPI were measured in ethanol and tetrahydrofuran at room and low temperature. DBPI displays molecular aggregation in water. The photochemical reactivity of DBPI was also studied in carbon tetrachloride upon irradiation with 525 nm light. The electrochemical investigation of DBPI dye has been carried out using cyclic voltammetry and convolution deconvolution voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP) in two different solvents acetonitrile (CH3CN) and dimethylformamide (DMF). The species were reduced via consumption of two sequential electrons to form radical anion and dianion (EE mechanism). In switching the potential to positive direction, the compound was oxidized by loss of two sequential electrons, which were followed by a fast dimerization and/or aggregation process i.e ECdim1ECdim2 mechanism. The electrode reaction pathway and the chemical and electrochemical parameters of the investigated compound were determined using cyclic and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.

Convolutive Cyclic Voltammetry Investigation of Dicarboximide Laser Dye at a Platinum Electrode in 1,2-Dichloroethane

Al-Bishri, Hassan M.,El-Mossalamy, E.H.,El-Hallag, Ibrahim,El-Daly, Samy Korean Chemical Society 2011 대한화학회지 Vol.55 No.2

N,N-bis(2,5-di-tert-butylphenyl) - 3,4,9,10 perylenebis(dicarboximide) 레이저 염료에 대한 전기화학적 연구가 0.1 M tetrabutyl ammonium perchlorate(TBAP)/1,2 dichloroethane($CH_2Cl-CH_2Cl$) 용액내에서 백금 전극을 이용하여 순환 전압-전류법 및 디지털 시뮬레이션 기술과 결합된 convolution-deconvolution 전압-전류법으로 수행되었다. 연구에 사용된 염료는 두개의 전자를 순차적으로 소모하며 radiacal anion과 dianion으로(EE 메커니즘) 환원되었다. 전위를 positive scan으로 전환하면, 이 화합물은 두 개의 전자를 잃고 산화된 뒤 빠른 응집 과정($EC_1EC_2$ 메커니즘)을 거치게 된다. 이 화합물의 전극 반응 경로, 화학 및 전기화학적 파라미터는 순환 전압-전류법과 convolutive 전압-전류법을 이용하여 측정되었다. 이렇게 구한 전기화학적 파라미터는 디지털 시뮬레이션 방법을 통하여 검증되었다. The electrochemical investigation of N,N-bis (2,5-di-tert-butylphenyl)-3,4,9,10 perylenebis (dicarboximide) laser dye have been carried out using cyclic voltammetry and convolution - deconvolution voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlorate (TBAP) in solvent 1,2 dichloroethane ($CH_2Cl-CH_2Cl$). The investigated dye was reduced via consumption of two sequential electrons to form radical anion and dianion (EE mechanism). In switching the potential to positive scan, the compound was oxidized by loss of two electrons, which were followed by a fast aggregation process ($EC_1EC_2$ mechanism). The electrode reaction pathway and the chemical and electrochemical parameters of the investigated compound were determined using cyclic voltammetry and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.

Preparation and Characterization of Ordered Nanostructured Cobalt Films via Lyotropic Liquid Crystal Templated Electrodeposition Method

Al-Bishri, Hassan M.,El-Hallag, Ibrahim S.,El-Mossalamy, Elsayed H. Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.12

A simple, inexpensive and less time consuming electrochemical methods were carried out to prepare ordered mesoporous cobalt films. Ordered mesoporous cobalt films were successfully synthesized by templated electrodepostion of hexagonal $H_1$-e Co ion. The electrodeposited mesopores films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), low angle X-ray diffraction (XRD) and voltammetric methods. The applicability of thin films as high - performance super capacitors electrode materials is demonstrated electrochemically using cyclic voltammetry (CV) technique.

Preparation and Characterization of Ordered Nanostructured Cobalt Films via Lyotropic Liquid Crystal Templated Electrodeposition Method

Hassan M. Al-Bishri,Ibrahim S. El-Hallag,ElSayed H. El-Mossalamy 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.12

A simple, inexpensive and less time consuming electrochemical methods were carried out to prepare ordered mesoporous cobalt films. Ordered mesoporous cobalt films were successfully synthesized by templated electrodepostion of hexagonal H1-e Co ion. The electrodeposited mesopores films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), low angle X-ray diffraction (XRD) and voltammetric methods. The applicability of thin films as high - performance super capacitors electrode materials is demonstrated electrochemically using cyclic voltammetry (CV) technique.