Volume 7

Importance of pyrazole carboxylic acid in MOFs preparation, Mohamed El Boutaybi, Abdelhafed Taleb, Rachid Touzani, Zahra Bahari, Arab. J. Chem. Environ. Res. 07 (2020) 01-11
1. University Mohammed Premier, Multidisciplinary Faculty of Nador, Laboratory of Molecular Chemistry, Materials and Environment (LMCME), Nador-Morocco
2. PSL Research University, Chimie ParisTech-CNRS. Paris Chemistry Research Institute, Paris 75005, France
3. University Mohammed Premier, Faculty of Sciences, Laboratory of Environment and Applied Chemistry (LCAE), Oujda-Morocco

Metal–organic frameworks (MOFs), constructed by organic linkers and metal nodes, are a new class of crystalline porous materials with signifi cant application potentials. Featured with extremely high surface area, large porosity, tunable pore size, and flexible functionality, MOFs have gained extensive explorations as a highly versatile platform for functional applications in many research fields. This short review presents the applications of metal-organic frameworks (MOFs) synthesized from pyrazolate derivatives. In fact, many pyrazolate ligands were examined: These ligands were used to synthesize a variety of MOFs that were subsequently investigated for batteries, luminescent sensing, gas storage, catalytic performance etc.

Kinetics and thermodynamic modelling of natural and synthetic goethite for dyes scavenging from aqueous systems, F.A. Ugbe and N. Abdus-Salam,  Arab. J. Chem. Environ. Res. 7 (2020) 12-28
1. Department of Chemistry, Faculty of Physical Sciences, Ahmadu Bello University, P.M.B. 1044, Zaria, Nigeria.
e-mail: ugbefabianaudu@gmail.com
2. Department of Chemistry, Faculty of Physical Sciences, University of Ilorin, P.M.B. 1515, Ilorin, Nigeria.
e-mail: nasalami2002@yahoo.co.uk

In order to significantly understand the mechanism of fixation of  dyes onto goethite surfaces, the kinetics and thermodynamic properties of natural goethite (NGT) and synthetic goethite (SGT) for methylene blue (MB) and eosin yellow (EY) adsorption was investigated. Batch equilibrium assay was used to study the influence of agitation time and temperature on the adsorption efficiency, results of which showed that the adsorption processes were dependent on both equilibrium parameters, with SGT exhibiting relatively higher adsorption capacity. The experimental data were fitted into some kinetics models (pseudo-first order, pseudo-second order, second order, Elovich, intra-particle diffusion (Weber-Morris), and film diffusion) while some thermodynamic parameters such as ∆G, ∆H, ∆S and isosteric heat of adsorption (∆Hr) were evaluated. The orders of fittings are pseudo-second order (R2 = 1) > Elovich (0.9717) > second order (0.9579) > pseudo-first order (0.8737), and Weber-Morris (0.9117) > film diffusion (0.8737). Thermodynamics study showed that the adsorption was feasible, spontaneous (all ∆G values are negative) and exothermic (except MB-NGT with ∆H = +0.538kJ/mol) in nature. Combined results of kinetics and thermodynamics studies suggested a combined chemisorptions and physisorptions processes as revealed by best fitting model (pseudo-second order) and magnitudes of ∆H (range of 20.9 – 80kJ/mol for EY and < 20.9kJ/mol for MB adsorption) and ∆Hr (> 40kJ/mol for EY and < 40kJ/mol for MB removal). Furthermore, the diffusion models suggested that intra-particle and film diffusion occurred simultaneously or in combination with other processes in the mechanism of adsorption.

Novel metal complexes as antimicrobial and anticorrosion in acid media, T. I. Kashar, K. M. Emran, A. Mo’ala, Arab. J. Chem. Environ. Res. 07 (2020) 29-49
1. Department of Chemistry, Faculty of Science, Menoufia University, Shebin El-Kom, Egypt.
2. Department of Chemistry, College of Science, Taibah University, Madina Monawara, Saudia Arabia.
E-mail: kabdalsamad@taibahu.edu.sa
3. Department of Chemistry, College of Science, Taibah University, Madina Monawara, Saudia Arabia.
E-mail: wsm_50@hotmail.com

New Cu(II),Co(II),Ni(II),Mn(II),Pt(IV),Fe(III) and Ag(I) complexes of Schiff base N-(2-hydroxyphenyl)-3-(2-hydroxyphenylimino ( were prepared and characterized by elemental analyses, IR, UV–Vis spectra, molar conductance, 1H NMR and mass spectra. Electronic spectral and magnetic moment studies indicate an octahedral geometry for the Cu(II),Ni(II), Co(II) and Fe(III) complexes while square planar geometry for the Pt(IV) and Ag(I) complexes. The Schiff base and their metal complexes were tested for their antimicrobial activities. The activity show that the complexes [LCu(H2O)2]2H2O, [L Mn2.(H2O)2]Cl2.4H2O and [LCo2(NO3)2] are more active than the Schiff base and Ampicillin towards Esherichia col and Staphylococcus aureus. The anticorrosion potency of H2L Schiff base and [LCu(H2O)2]2H2O, [(HL)Co(H2O)Cl]5H2O and [LNi(H2O)2]2H2O complexes was investigated for carbon steel in 1.0 mol L-1 H2SO4 solution using electrochemical methods. Detailed electrochemical polarization and impedance studies prove that H2L Schiff base is mixed-type inhibitors and improved adsorption of H2L Schiff base species on carbon steel surface at increased concentrations reaching a maximum efficiency of 83.08%. Inhibition activity of newly synthesized [(HL)Co(H2O)Cl]5H2O complex on carbon steel gets enhanced significantly due to the presence of chloride ion inside the  coordination sphere , which possesses many lone pair of  electrons which enhances the bond with the steel.

Reproduction of the Whiskered Tern Chlidonias hybrida near Tnine Al Gharbiya (Province of Sidi Bennour), A. Rihane, R. El Hamoumi, Arab. J. Chem. Environ. Res. 07 (2020) 50-65
1. Département des Sciences de la Vie et de la Terre, Centre Régional des Métiers de l’Education et la Formation (CRMEF) Casablanca-Settat – Casablanca (Morocco) abdeslam.rihane@gmail.com
2. Laboratoire d’Ecologie et d’Environnement, Faculté des Sciences Ben M’sik, Université Hassan II – Casablanca (Morocco)
3. GREPOM-BirdLife, Résidence Oum Hani 3, Avenue Ouali Al Had Sidi Mohamed – Salé (Morocco)

The nesting of the Whiskered Tern Chlidonias hybrida has been known in Morocco since the 1940s, but the number of nesting sites remains very limited, and the sites very remote and isolated. More recently, the nesting of this species was noted in the Marrakech-Safi region. In the Doukkala plain of Moroccan Atlantic flatlands, characterized by a very large number of dayas, the daya of Lgandaziya at Tnine Al Gharbiya is the only site where we recorded for the first time in 2016 a nesting case of a small population of this species with 12 nests.

Recent advances in chitosan-based electrochemical sensors and biosensors, Abdelhafid Karrat, Aziz Amine, Arab. J. Chem. Environ. Res. 7 (2020) 66-93
Laboratory of Process Engineering and Environment, Faculty ofSciences and Techniques, Hassan II University of Casablanca, P.A. 146., Mohammedia, Morocco

Chitosan is a biopolymer derived from chitin. It is a non-toxic, biocompatible, bioactive, and biodegradable polymer. Due to its properties, chitosan attracted considerable attention in several fields such as agriculture, food industry, medicine, paper fabrication, textile industry, and water treatment. In addition to these properties, chitosan has a good film-forming ability which allows it to be widely used for the development of sensors and biosensors. This review will be focused on the use of chitosan-based composites for the preparation of the electrochemical sensors. It also aims to provide an overview of the advantages of using chitosan as an immobilization platform for biomolecules by highlighting its applications in electrochemical biosensors. Furthermore, the application of molecularly imprinted chitosan for the preparation of the electrochemical sensors will be discussed.

Review: Synthesis of Crystalline Nanocellulose by Various Methods, A. Haerunnisa, D. Ramadhan, H. A. Y. Putra, N. Afiifah, R. Devita, S. Rahayu, A. B. D. Nandiyanto, Arab. J. Chem. Environ. Res. 07 (2020) 95-125
1. Departemen Pendidikan Kimia, Fakultas Pendidikan Matematika dan Ilmu Pengetahuan Alam, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi no. 229, Bandung 40514, Jawa Barat, Indonesia dangboyrama17@upi.edu

Crystalline nanocellulose is an important material in supporting the needs of the industrial sector today. Because of its many uses, encouraging researchers to develop crystalline nanocellulose synthesis methods with various treatments and sources. Of the many methods, not all of them can be applied on an industrial scale. Therefore, the author aims to review the literature on the synthesis of crystalline nanocellulose so that we know which methods can be applied on an industrial scale. In this paper, we review 60 papers from 1995 to 2020 then highlight 12 representative recent papers. This review is expected to be a reference in selecting crystalline nanocellulose synthesis methods for industrial use, given the lack of specific reviews on crystalline nanocellulose synthesis for industrial-scale applications. From the results of the review of several papers, the team of authors believes that the synthesis of nanocellulose which is suitable for application on an industrial scale is the acid hydrolysis method. This is based on the findings that with this synthesis, more samples are obtained, the process is more efficient, following current industrial developments and the materials used can be agricultural waste which is rarely seen in the industrial world.

Effect of substitution on corrosion inhibition properties of three Imidazole derivatives on mild steel in 1M HCl, M. Bouklah, H. Elmsellem, O. Krim, G. Serdaroğlu, B. Hammouti, A. Elidrissi, S. Kaya, I. Warad, Arab. J. Chem. Environ. Res. 07 (2020) 126-143
1. LCAE-URAC18, Faculty of Science, University Mohammed Premier, B.P. 717, 60000 Oujda, Morocco, e-mail: boukmmm@yahoo.fr
2.Sivas Cumhuriyet University, Faculty of Education, Math. and Sci Edu., 58140, Sivas/Turkey E-mail: goncagul.serdaroglu@gmail.com
3. Sivas Cumhuriyet University, Health Services Vocational School, Department of Pharmacy, 58140, Sivas/Turkey. E-mail: savaskaya1989@gmail.com
4. Department of Chemistry and Earth Sciences, PO Box 2713, Qatar University, Doha, Qatar E-mail: ismail.warad@qu.edu.qa

In this paper, we study the effect of substitution of three imidazoles: 1-vinyl-1H-imidazole (VyIm); 1-(2-Dodecylsulfanyl-ethyl)-1H-imidazole (DEEIm) and 2-Imidazol-1-yl-ethylsulfanyl)-acetic acid (ImESAA) on adsorption properties on the steel surface in molar HCl solution. The investigation was performed using weight loss data combined to theoretical parameters deduced from dynamic simulation. Various kind of Langmuir, Temkin, Frumkin, Freundlich, Flory-Huggins and El-Awady were investigated and discussed. The higher inhibition efficiency of DEEIm was explained by the length aliphatic chain leading to reinforce charge on sulfur atom and imidazole ring. Free enthalpy and other data deduced from isotherm kinds help to understand adsorption process. The DFT calculations were performed to estimate the chemical reactivity of the VyIm, ImESAA and DEEIm compounds at B3LYP/6-311++G(df,pd) level.

Spectrophotometric and Conductometric Study of Formation Constant and Stoichiometry of Co(II)-Salen Type Ligand Complex, K. M. Elsherif, A. Zubi, H. B. Shawish, S. A. Abajja, and E.B. Almelah, Arab. J. Chem. Environ. Res. 07 (2020) 144-157
1. Chemistry Department, Faculty of Science, University of Benghazi, Benghazi, Libya., e-mail: elsherif27@yahoo.com
2. Chemistry Department, Faculty of Science, Misurata University, Misurata, Libya

Chelation of Co(II) with N,N-Bis(Salicylidene) ethylenediamine (salen type ligand) have been investigated spectrophotometrically and conductometrically in various solvents (methanol, 2-propanol, acetonitrile, and chloroform). By spectrophotometric measurements, the chelation was performed at 25°C at the wavelengths of the corresponding complex. The stoichiometry of the complexes in each solvent were evaluated using continuous variation method and mole ratio method and the values were found to be 1:1 (M:L). Formation constants (Kf) values were found to be in the order of 109 – 1010 in the examined solvents. The results show there is no significant difference in formation constant values between the complexes formed in the tested solvents. However, the complex formed in chloroform has a slightly larger values of Kf compared to the other solvents. The stability and stoichiometry of the tested complex in MeOH, PrOH, MeCN and CHCl3 at 25°C by conductometric method were also evaluated. Conductometric measurements indicate the formation of (1:1) complexes with stability order: CHCl3 > MeCN > PrOH > MeOH and that was in agreement with the spectrophotometric results. The thermodynamics of the complexation reaction in MeOH was also investigated by conductometric measurements. The stability constant values increase with increasing temperature which means that the complexation reaction is an endothermic process. The negative value of ΔG shows the ability of the Salen ligand to form stable complex with Co(II) and the process trend to proceed spontaneously.

Level of Contamination in Lakes and Rivers of Ethiopia: an Overview, M. Mulugeta, R. Sahilu, Z. Kibret & M. Mersha, Arab. J. Chem. Environ. Res. 07 (2020) 158-174
1. Department of Chemistry, Kotebe Metropolitan University, P.O. Box 31248, Addis Ababa, Ethiopia, e-mail: millionppp@gmail.com
2. Department of Environmetnal Mangement, Kotebe Metropolitan University, P.O. Box 31248, Addis Ababa, EthiopiaE-mail: robisha@gmail.com
3. Department of Chemistry, Kotebe Metropolitan University, P.O. Box 31248, Addis Ababa, Ethiopia,. E-mail: zkibre@gmail.com
4. Department of Water Quality Control, Addis Ababa Water and Sewerage Authority, Addis Ababa, Ethiopia E-mail: mihret01@gmail.com

Water is a resource that is required by all living things. Ethiopia is being known as the roof tower of Africa is rich with surface and groundwater resources. The status of pollution in Ethiopia water bodies is yet to be reviewed. So, in this review, the status of pollution in lakes and rivers of Ethiopia is overviewed. Ethiopia water bodies are getting pollution due to the rapid growth of small-scale and medium industries, geological routes, nutrient enrichment, and other anthropogenic activities. The high concentrations of heavy metals (As, Zn, Cr, Cu, Hg, Pb, Cd, and Ni), pesticides, and pathogens beyond permissible limits by WHO in the water bodies from different anthropogenic and natural pathways are a great problem. Their entry into the ecological food chain and the resulting health effects are of great concern for the future. Most of the studies carried out on physical, chemical, bacteriological, and invasive weeds like water hyacinth pollution issues in Ethiopia are dedicated to the characterization and the quantification of the pollution. Moreover, proper mitigation majors and interventions are required to avoid the problems that result from the contaminants for the incoming generation.

Evaluation of physiochemical, antioxidant, proximate and nutritional values of virgin coconut oil (Cocus nucifera), M. U. Adaji, E. M. Ameh, S. O. Usman, A. D. Jacob and F. O. Onoja, Arab. J. Chem. Environ. Res. 07 (2020) 175-190
1. Department of Chemistry, Kogi State University, Anyigba, Nigeria, e-mail: adajimed@gmail.com; Markameh2004@yahoo.com ; Usman2great@gmail.com ; Jacob.a@ksu.edu.ng; daleonoja@gmail.com

Virgin coconut oil can be a good food supplement due to its high medium – chain fatty acids unlike other cooking oils which contain long – chain fatty acids. This research is to investigate the physiochemical, antioxidant properties, proximate and nutritional values of Virgin coconut oil (VCO). The extract of virgin coconut oil was investigated for its proximate and nutritional composition showed that coconut oil can be good food supplement. The physiochemical parameters showed low iodine, saponification, peroxide, and acid value of 0.5918, 134.50, 1.5 and 0.673 meq/kg respectively. The antioxidant activity was investigated using DPPH free radical scavenging, the result showed that the VCO inhibits in the range of (37.0 – 61.0) % while Vitamin C (control) inhibits within (93-97) %. The proximate and nutritional values analyses showed that the moisture content, ash content, crude fibre, crude protein, crude lipid, and carbohydrate were 14.28, 1.075, 7.22, 9.255, 39.72 and 28.45 respectively. Minerals found were K, C, Na, Fe, Ca, Zn and P 138.15, 0.015, 58.6, 1.82, 38.55, 5.35 and 0.79 mg/kg respectively..