Open Access Short communication

Some Concepts about Substance, Chemical Compound and an Element

B. T. Utelbayev, E. N. Suleimenov, A. Utelbayeva, N. Zhanabai

Chemical Science International Journal, Page 166-173
DOI: 10.9734/ACSJ/2014/6732

Chemistry is the science that deals with the composition and properties of matter.   Properties of matter are generally grouped into two broad categories; these are physical and chemical properties. Physical property is the one that a sample of matter displays without changing its composition. The physical and chemical properties of a substance depend on its size and the arrangement of elements in the chemical compound. Considering physical and chemical properties of matter, it is demanded that the difference between atom and chemical element, chemical compound and substance concepts demand that we distinguish them. In this paper, these concepts are considered on microscopic and macroscopic levels.

 

Open Access Original Research Article

Chemical Fractionation of Copper, Manganese and Zinc in Dumpsite Soil Samples in Kaduna Metropolis, Nigeria

Ekwumemgbo Patricia Adamma, Omoniyi Kehinde Israel, Sanni Habib Adinoyi

Chemical Science International Journal, Page 138-150
DOI: 10.9734/ACSJ/2014/6001

Aims: In this research, sequential chemical extractions were performed to fractionate copper, manganese and zinc in dumpsite soil samples into six geochemical fractions with varying mobility and bioavailability.

Study Design: Determination of chemical forms of metals in soils and evaluation of their mobility and bioavailability.

Place and Duration of Study: This study was conducted between March, 2011 and June, 2013 in the Department of Chemistry, Ahmadu Bello University, Zaria, Nigeria.

Methodology: Collection of soil samples from Kawo (KW), Rafin Guza (RG), Angwan Dosa (AD), Badarawa (BD), Malali (ML), Angwan Shanu (AS), Kurmi Mashi (KM), Tudun Wada (TW), Kakuri (KK) and Trikania (TK) dumpsites; sequentially extraction of samples into six fractions and determination of metal concentrations in extracts.

Results: Copper had high mobility factor values in the rainy season at TK (43.76%), TW (13.51%), AS (13.48%) and ML (0.14%); and in the dry season at TK (44.79%), KW (14.65%), AS (14.18%), ML (13.43%) and TW (13.31%). Manganese in the rainy season recorded relatively high mobility values at KK (2.18%), AD (2.07%), and TW (1.67%) and in the dry season at ML (2.57%), BD (2.23%), KK (2.06%) and TW (1.51%) while Zinc had high mobility values in the rainy season at BD (54.14%), AS (26.62%), KM (18.08%), TK (16.11%), ML (5.88%) and KK (3.54%) and in the dry season at RG (145.79%), BD (44.59%), AS (31.08%), KM (21.65%) and TK (18.19%). Copper and zinc were distributed evenly across the non-residual and residual fractions, while manganese was predominantly retained by residual fractions. The mobility and potential bioavailability of the metals in decreasing order is: zinc > Copper > Manganese.

Conclusions: The amount of metals bound to each fraction differed significantly according to metal type, dumpsites and seasons. The study indicates the tendency for bioavailability of the metals studied for plant uptake from soil.

 

Open Access Original Research Article

Solution Based Cation-Exchange Process to Control Optoelectronic Properties of Cadmium Sulphide Thin Films

Uma Nerle, M. K. Rabinal

Chemical Science International Journal, Page 151-165
DOI: 10.9734/ACSJ/2014/6797

The control of optoelectronic properties of cadmium sulphide films, by a simple solution based ion exchange process, is an important aspect for various applications. The effect of post doping of certain metal ions on chemical bath deposited cadmium sulphide thin films has been studied in this work. An alkaline bath has been developed to obtain highly homogeneous CdS films on various substrates. X-ray diffraction of these films reveals that as deposited material is amorphous. The energy dispersive x-ray analysis confirms that a reasonable amount of cations can be incorporated into these films without affecting its atomic structure. Optical absorption and electrical conductivity measurements suggest that there is a clear effect of cation-exchange with respect to lead, silver and copper ions. Electrical conductivity is significantly improved by copper ions, this change is close to five orders of magnitude with respect to intrinsic films. These results clearly show that both substitutional and interstitial mechanisms are involved in the cation-exchange process of these films.

 

Open Access Original Research Article

Effect of Anions, Complexing and Salting - out Agents on the Extraction of Mo (VI) from Acid Media into Chloroform Solution of Bis (4-Acylpyrazolones)

I. A. Kalagbor, B. A. Uzoukwu

Chemical Science International Journal, Page 174-186
DOI: 10.9734/ACSJ/2014/5588

The extraction of Mo (VI) was carried out in the presence of a synergist in the organic phase and also in the presence of the corresponding acids (HCl and H2SO4).

The effect of the anions, Cl-, SO42- , Br- , I- , SCN-, PO43-, EDTA, Oxalate, acetate and tartarate on the extraction of Mo (VI) into chloroform solutions of 4-adipoylbis (1-phenyl-3methylpyrazolone-5), H2Adp and 4-sebacoylbis (1- phenyl-3-methylpyrazolone-5), H2SP were studied.  The results showed that the masking effect of the halides on the extraction of Mo (VI) followed the increasingly order Cl-<Br-<I-. The trend follows the direction of decrease in electro negativity. Similarly, the extraction of Mo(IV) is increasingly masked with increase in concentration of the complexing agents, decreasing the % extraction from as high as 60% extraction at 10-3M ligand concentration to as low as10% at 1M ligand concentration.  The extraction of the metal is greatly enhanced in the presence of their corresponding acid solution by increasing the extraction by as high as 10- 40% and also in the presence of butanol. Under all conditions, H2SP showed to be a better extract ant than H2Adp:

 

       H2SP >> H2Adp

 Decrease in BuOH Synergism

 

Open Access Original Research Article

Effect of Cu2+ Concentration on Adsorption - Sorption Mechanisms, Modes, Critical Concentration Edge, and Spontaneity of Octahedral [Cu (H2O) 6]2+ on γ Alumina

Adel R. Ismaeel, Khaled M. Edpye

Chemical Science International Journal, Page 187-198
DOI: 10.9734/ACSJ/2014/5852

Aims: To apply a fast, & save method for water treatments by using physical removal of toxic metal ions such as Cu2+ by adsorption at solid insoluble, non toxic, reusable adsorbent as γ Alumina. to indicate the effects of Cu2+ concentrations ranges on the adsorption modes, mechanisms,  maximum efficiency, and the thermodynamic parameters indicating spontaneity of the processes. As we have to get strong adsorption to avoid desorption of ions to solution but the low apparent adsorption spontaneity was contradicted (not inconsistent) with the produced high strength of adsorption) encourage us to determined the true free energy change for each adsorption mode by studying the adsorption mechanism and energy relations of each adsorption mode.

Place and Duration of Study: Benghazi University, Chemistry Department, Benghazi, Libya between Sep 2009 and Dec 2011.

Methodology:  Solutions of concentrations from, 1.5 to 15.5 x10-3M of Cu2+ which resembling that of industrial, agriculture, and waste water. Cu2+ form cupric water octahedral complex ion, (CWOCI) [Cu(H2O)6]2+ was prepared by dissolving in buffer solution to be maintained at pH = 4.5. The  batch technique of adsorption test was followed in testing 50 ml of each test solution which was simultaneously shacked with 0.5 gram adsorbent ( γ Al2O3 ) for 60 minutes with shacking rate of 300 cycle per minute using water thermostat shaker at 30ºC. The amount of Cu2+ adsorbed was determined by measuring the difference of its concentration before, and after adsorption by measuring the optical density of the blue [Cu (NH3)4)]2+ at pH=11 formed by adding NH4OH to Cu2+ solution, using spectroscopic method  with a beam of wave length  580nm.

Results: The results were applicable to Langmuir, and Ismaeel adsorption isotherms all over this concentration range but it show a deflection of Langmuir line, and deflection with splitting of Ismaeel line at the same equilibrium concentration edge (CE)= 3.3 x 10-3mole  which divided  the isotherms into two low, and higher concentrations ranges. The same divisions were occurred also to the lines of the relations of the solution concentration versus adsorption rate, the surface coverage fraction θ, the adsorption efficiency % and spontaneity indicating two modes and mechanisms of adsorption before and after CE.

Conclusion: We have to avoid applying adsorption processes on concentrations higher than the CE, by using dilution with pure water to just lower the concentration than CE or by increasing the mass of adsorbent. To gain maximum (adsorption- sorption), Spontaneity, Efficiency, Rate and Surface coverage %.

Applying Ismaeel adsorption isotherm, enable to know the adsorption modes and activation energy used to release and replace the water molecules already adsorbed on adsorbent surface, and determining the true value of adsorption free energy change which identify the adsorption type as, chemisorptions confirmed by the high adsorption spontaneity as ∆G true reached more negative than -296 KJM-1. The length of the long axes of (CWOCI) was exactly calculated from experimental results, which was difficult to be determined by (XAFS) technique.

 

Open Access Original Research Article

Assessment of Some Biochemical Parameters in Iraqi Pregnant Women with and Without Complications

Israa G. Zainal, Zaizafoon Nabil

Chemical Science International Journal, Page 199-206
DOI: 10.9734/ACSJ/2014/5452

Aims: The purpose of this study was to evaluate and compare some biochemical parameters including [ceruloplasmin oxidase(CP), α – fetoprotein (AFP), interleukine-1 (IL-1), α2- macroglobulin (α2 – MG), α1 antitrypsin(α1 – AT)] and β-human gonadotropin(β -HCG)] in Iraqi women with pregnant complications ( mole ,ectopic and missed abortion )  compared with normal pregnant women .

Study Design: This is a case-control study which included 63 women with pregnant complications (25 with missed abortion having - mean age 26.68 ± 7.54 yrs, 21 with mole having - mean age 26.14± 8.19 yrs and 17 having ectopic - mean age 26.14 ± 6.99 yrs) pregnancy and 25 normal pregnancy women with mean age 25.16 ± 5.97 yrs as control.

Place and Duration of Study: Samples collected from the Baghdad Medical City, AL-Yarmook and Fatema AL-Zahraa hospitals during the period from September 2011 to April 2012.

Methodology: Alpha feto protein, IL- 1, α2 – MG, α1 – AT and β -hCG were measured by immunoassay method. CP activity was measured using the modified Rice method.

Results: AFP and IL-1 were significantly decreased (p≤ 0.05) in all patients groups but Cp, activity was decreased significantly only in EP and MP groups (p≤ 0.05). There was a significantly increased (p≤ 0.05) in β-hCG level in mole or missed abortion and significantly decreased (p≤ 0.05) in ectopic pregnancy compared with controls. α2-MG levels were significantly increased in EP , MP compared to control.α1-AT were elevated significantly (p≤ 0.05) in all women with pregnancy complications compared with controls.In mole pregnancy there were positive correlation between α2 – MG with β-hCG (r= 0.51, p= 0.01) or with α1 – AT (r= 0.49, p= 0.02) and negative correlation between AFP with α1 – AT (r= - 0.41, p= 0.05), IL- 1 with α2 – MG(r= - 0.44, p= 0.04). CP positively correlated with IL- 1 (r= 0.734, p= 0.00) while in missed abortion there were positive correlations between β-hCG and AFP (r= 0.42, p= 0.034), IL-1α (r = 0.83, p= 0.00) with α2-MG (r = 0.060, p= 0.00) and between AFP with α2-MG (r = 0.45, p= 0.02) and between IL- 1 with α2-MG (r = 0.75, p= 0.00).        

Conclusion: This study shows that the above biological parameters could be used for the monitoring the health status of pregnant women with complications.

 

Open Access Original Research Article

The Reactions of Hydrochlorides of 2, 3-Tri (Tetra) Methylene-3, 4-Dihydropyrimidine-4-Ones with N-Bromosuccinimide and Bromine

N. I. Mukarramov, Kh. Z. Khakimova, A. O. Nasrullaev, Kh. U. Khodjaniyazov, Kh. M. Shakhidoyatov

Chemical Science International Journal, Page 207-215
DOI: 10.9734/ACSJ/2014/7060

Aims: To carry out reactions between hydrochlorides of 2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones and N-bromosuccinimide (and/or bromine), to determine way of reactions.

Study Design: Official design.

Place and Duration of Study: Department of Organic Chemistry, Institute of the Chemistry of Plant Substances (ICPS) between January 2012 and September 2013.

Methodology: We have synthesized 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones from ethyl b-aminocrotonate and g-butyro- or d-valerolactames in the presence of different agents, such as РСl5, POCl3 and SOCl2. For convenient operations the oily bases of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones have been transmuted into the appropriate hydrochlorides. Bromination by equimolar amount of hydrochlorides with N-bromosuccinimide at room temperature in water gives 5-bromo-6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones. Treatment of them by bromine resulted in the formation of perbromides. The reactions were monitored  and controlled by TLC. Bromine-products were characterized by IR, 1H NMR, mass-spectra determinations and chemical transformation.

Results: Electrophilic substitution at C5 atom was successfully carried out when we have used N-bromosuccinimide. Perbromides of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones were produced when we have used bromine. Perbromides performed to hydrobromides and bromine complexes when we have treatment of them by acetone and NaHCO3 solution respectively.

Conclusion: Bromination of hydrochlorides of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones by N-bromosuccinimide gives 5-bromine-derivatives. Bromination of them by bromine followed to the formation of perbromides of 6-methyl-2, 3-tri(tetra)methylene-3, 4-dihydropyrimidine-4-ones which are performed to hydrobromides and bromine complexes when we have used corresponding treatments.

 

Open Access Original Research Article

Conformational Study of Hard-core Liquid Crystalline Schiff Bases Containing 1,3,4-Oxadiazole Ring

Juman A. Naser, Yousif I. Mohammed, Taki A. Himdan, Ammar H. Al-Dujaili

Chemical Science International Journal, Page 216-228
DOI: 10.9734/ACSJ/2014/6346

The relaxed torsion potential of a hard-core Schiff bases of 1,3,4-oxadiazole liquid crystalline series has been studied by molecular modeling techniques. First, conformational search of the molecules was made at molecular mechanics MM+ in order to simplify calculations, so to find the lowest and highest energy conformation structure. In a second stage, geometry optimization calculations of these conformers were performed at the quantum mechanics semi-empirical PM3and RM1 levels in order to obtain more information about the structure and the stability of this core through identification the global minimum energy. Potential energy surfaces (PES) curve has been obtained from plotted the energies against the dihedral angles (θ1, θ3, and θ5). The results show that the core of the molecule did not lie in the same plane. But the π-conjugation is between the segments (A, B) which lay in the same plane and other π-conjugation between segments (C, D) which lay in other plane.

 

Open Access Original Research Article

Kinetics of Methylene Green and Ascorbic Acid Reaction in Aqueous 2-propanol at Different Temperatures

Zahida Khalid, Rehana Saeed, Fahim Uddin, Maria Ashfaq

Chemical Science International Journal, Page 229-241
DOI: 10.9734/ACSJ/2014/7136

The kinetics of reaction of methylene green with ascorbic acid was carried out spectrophotometrically in mixed solvent system by using aqueous 2- propanol ratios as a solvent in the presence of hydrochloric acid. The pseudo-first order rate constants were proposed on the basis of the experimental kinetic data.

The reaction was carried out in 10%, 20%, 30%, 40%, 50% aqueous 2-propanol ratios at different ionic strength. The effects of these solvent compositions and ionic strength on rate of reaction were studied. The effect of concentration of ascorbic acid on the rate of reduction was also determined. The values of rate constants at all initial concentrations of methylene green revealed that reaction follows 1st order kinetics with respect to ascorbic acid and relatively higher value of the rate of the reaction was observed in the solvent of high dielectric constant. The reaction was found to be zero order dependence on the concentration of methylene green, and the variation of hydrochloric acid concentration did not bring about significant changes in the values of rate constants in various aqueous propanol mixtures.

The influence of temperature on the rate constant as a function of ascorbic acid concentration was also studied. The Arrhenius relationship was used to determine the various activation parameters such as activation energy (Ea), change in enthalpy (DH#), change of entropy (DS#), and the change of free energy of activation (DG#). The activation parameters determined were found to be dependent on concentration of ascorbic acid and solvent composition. The radii of the activated complex was calculated. It was found that activated complex exists as a single sphere model. The iso-kinetic temperature was also calculated.

 

Open Access Original Research Article

Electron Transfer Reaction of Pyridoxine (Vitamin B6) with Keggin Type 12 Tungstocobaltate (III) in Aqueous Perchlorate Medium

Sadhana Senapati, A. K. Patnaik, S. P. Das, P. Mohanty

Chemical Science International Journal, Page 242-254
DOI: 10.9734/ACSJ/2014/6880

Transition metal substituted heteropolymetalates exhibit different chemical and electrochemical properties.  The complexes of transition metal ions with polyoxanions such as polytungstates are well known as outer-sphere electron transfer reagents. 12-tungstocobaltate (III) has the well-known twelve tungsten atoms Keggin structure. Such  clusters  are  known  for  photochemical, hydrogen  generation  and are involved in multi-step  electron  transfer  processes. Keeping this view in mind the interaction of vitamin B6 with 12-tungstocobaltate (III) has been carried out.

The kinetics of the electron transfer reaction of vitamin B6 with 12-tungstocobaltate (III) complex has been studied spectrophotometrically over the range 0.01 ≤ (pyridoxine)          ≤ 0.07mol dm-3, 3.3 ≤ pH ≤ 5 and at 298 K ≤ T ≤ 318K in aqueous perchloric acid medium. Kinetics measurements were run under pseudo-first order conditions. The rate of electron transfer reaction was found to be first order with respect to pyridoxine. The results showed that the rate depends on size and strength of the ligand. The activation parameters favored the electron transfer reaction.

Interaction of pyridoxine (Vitamin B6) with 12-tungstocobaltate (III) in aqueous perchloric medium involves formation of a precursor complex between reactants. The precursor complex undergoes a reorganisation towards a transition state in which electron transfer takes place to form pyridoxal as an intermediate. The pyridoxal is further oxidized to a final product 4-pyridoxic acid by another oxidant molecule in the fast step. The product is confirmed by FTIR and 1H NMR spectra.