ORIGINAL_ARTICLE
Inner-sphere Oxidation of Acetato- diaqua-(2-hydroxobenzy- lidene)- 5- phenylthiazol- 2- amino Cobalt (II) Complex by N-bromosuccinimide
KINETICS oxidation of acetato- diaqua-(2-hydroxobenzylidene)-5-phenylthiazol-2-amino cobalt (II) complex by N-bromosuccinimide (NBS) in aqueous media was studied spectrophotometrically over the 25
–40 o+C range, 0.2 -0.5 mol dm-3 ionic strength, and pH range (6.1-7.3) for a range of NBS and [complex]. The reaction rate was first order dependence on [NBS] and [complex] and increased with decreasing [H+] over the pH's values. The experimental rate law was consistent with a mechanism in which the deprotonated form of the complex was considered as more reactive than its conjugate acid. Polymerization of acrylonitrile was taken as an evidence for the presence of free radical in the reaction mixture. It was assumed that electron transfer took place via an inner-sphere mechanism through the formation of the initial cobalt (III) products which were slowly converted to the final cobalt (III) products.
https://ejchem.journals.ekb.eg/article_1137_7984f5cc767833d1388648e254f75f73.pdf
2012-04-30
111
124
10.21608/ejchem.2012.1137
Kinetics
Oxidation of cobalt (II) complex and Oxidation with N-bromosuccinimide
ORIGINAL_ARTICLE
Studies on Cyclic Ketones: Synthetic Routes to Indenopyridine, Indenopyran, Fluoreneoxime, Pyrazoloindenotriazine and Indenopyridazine Derivatives
SEVERAL new indenopyridine, indenopyran, fluorenoneoxime, indenopyridazine and pyroloindenotriazine derivatives were prepared using cyclic ketones (1), arylmethylenenitriles (2) and active methylene nitriles 3 as starting materials.
https://ejchem.journals.ekb.eg/article_1138_f23fd00641c0df25c7233093aa620b1b.pdf
2012-04-30
125
141
10.21608/ejchem.2012.1138
ORIGINAL_ARTICLE
MMT Modified with Cationic Carbohydrates as Deliver Carrier for Praziquentel Drug
UTILIZATION of modified MMT in drug delivery is now taking a …….great attention due to the considerable efficiency and miscellaneous drug type. In this study, different types of cationic carbohydrate are used for MMT to optimize the best for loading and release. Tert- aminated starch (AmS) and chitosan (CS), bearing primary amino groups, are used for modification of MMT to evaluate the feasibility of loading and release of Praziquantel drug with applicable efficiency. The modified clay was characterized by XRD, TGA and SEM. The characterization via XRD and SEM demonstrates that the chitosan has greater exfoliated intercalation properties than the Tert- aminated starch. The loading efficiency of Praziquantel by modified MMT with AmS, and chitosan was 19.5 % and 22.1 % , respectively. Drug release was studied for CS/MMT –Praziquantel hybrid and it was found that the release was directly proportional with the pH of the medium and reached to 82% at pH 7.4 after 6 hr.
https://ejchem.journals.ekb.eg/article_1139_15a43f696b63dd051982280cef7d26d4.pdf
2012-04-30
143
159
10.21608/ejchem.2012.1139
MMT
Aminated starch
Chitosan
Drug delivery
Praziquantel and Characterization
ORIGINAL_ARTICLE
Pure Chromium Sulfate Heptahydrate from Waste Tanning Solutions
THIS work defines a method for the preparation of pure chromium sulfate heptahydrate from waste tanning solution. The waste resource contains free and soluble fats, calcium hydroxide, iron, magnesium as soluble elements together with chromium ions. The waste solution was filtered to get rid of insoluble materials. This was followed by removal of calcium, iron and magnesium by precipitation as insoluble oxalate salts using 1.3 stoichiometric ratio of oxalic acid in faint acidic medium. Soluble fats were removed by solvent extraction using 1:1 mixture of petroleum ether and isopropanol at 60°C. The remaining solution contains chromium sulfate together with minor fat impurities. Chromium was selectively precipitated as insoluble hydroxide cake at pH 8.5. Polyacrylamide (0.05%) solution helps fast agglomeration and sedimentation of Cr (OH)
3. The hydroxide was washed repeatedly with hot distilled water. The hydroxide cake was partially dehydrated prior to reaction with pure sulfuric acid to prepare pure chromium sulfate solution. Dry chromium sulfate heptahydrate salt was prepared by addition of absolute ethyl alcohol at room temperature whereby the salt is insoluble in alcohol. The influence of some parameters that affect the productivity of the method was studied.
https://ejchem.journals.ekb.eg/article_1140_725c3c92b61905c8c203761aa044e7fc.pdf
2012-04-30
161
178
10.21608/ejchem.2012.1140
Chromium sulfate
Tanning waste solutions
Precipitation and Chemical techniques
ORIGINAL_ARTICLE
Monitoring of Some Pollutants in Sediments of Damietta Estuary and Its Impacts on Coastal Share in front of Damietta Governorate
THE ANALYSIS of distribution pattern of heavy metals Fe, Mn, Zn ,Cu, Pb , Cd , Ni ,Cr, Co, Mo As, Al and Hg in sediment, of Damietta estuary and in front of Mediterranean coastal shoreline was carried out through four successive cruises (February to November 2008). The results revealed that, heavy metals in the Damietta Estuary were higher in concentrations than those of Mediterranean shoreline. This is due to the industrial and domestic waste discharges and return flow of agricultural drainage water. Furthermore, the heavy metals content decreased progressively while moving away from Damietta Estuary to Mediterranean shoreline which declared that heavy metals content of Mediterranean shoreline depends on its distribution pattern in Damietta Estuary. The order of the detected concentration of heavy metals in sediment samples in Damietta Estuary and Mediterranean shoreline concentration is Fe > Mn > Al > Zn > Cr > Pb > Ni > Co > Cu > As > Cd > Hg > Mo and Fe > Mn > Al > Zn > Cr > Ni > Co > Pb > Cu > As > Cd > Hg > Mo, respectively.
https://ejchem.journals.ekb.eg/article_1141_77158cc2adf05f0b848d3a57e24e57e2.pdf
2012-04-30
179
189
10.21608/ejchem.2012.1141
ORIGINAL_ARTICLE
Synthesis and Biological Activity of Novel Thieno [2,3-d] [1,2,4] triazolo [4,3-a] pyrimidine and Pyrazolo [3,4-c] pyrazole Derivatives
REACTION of hydrazonoyl halides (2a-e) with either 1,2,3,5,6,7- ..........hexahydro-4H-cyclopenta[4,5]thieno[2,3-d] pyrimidin-2, 4-dithione (1) or 2 (4- Dihydro – 5 – oxo – 3 – methyl - 1H – pyrazolo – 1 – yl ) -5,6,7,8-tetrahydrothieno[2,3-d]pyrimidin-4(3H,4H) -one (11) in the presence of sodium ethoxide in refluxing ethanol / DMF mixture afforded the cyclopenta [4,5]thieno[2,3-d]triazolo [4,3-a]pyrimidines-4-thiones (7a-d) and the phenylpyrazolo[3,4-c]pyrazolcyclopenta [4,5] thieno [2,3-d] pyrimidin-4-ones (14a-e), respectively. The mechanism of the studied reactions has been discussed and the biological activity of the products 7a-d has been evaluated.
https://ejchem.journals.ekb.eg/article_1142_4fa753101bba767c9322c38abc0bb6f2.pdf
2012-04-30
191
200
10.21608/ejchem.2012.1142
Hydrazonoyl halides
[1
2
4] Triazolopyrimidine
Rearrangement
Pyrazole and Biological activities
ORIGINAL_ARTICLE
Novel Cationic Schiff Base Surfactants: Surface Studies and Biocidal Activities against Bacteria Fungi and Sulfate Reducing Bacteria
NOVEL series of cationic Schiff base surfactants were synthesized …….and characterized using microelemental analysis, FTIR and 1H-NMR spectra. The properties of the synthesized surfactant solutions such as critical micelle concentration (CMC), effectiveness (ΠCMC), surface excess concentration (Гmax), surface area (Amin) and free energy of micellization (ΔGmic) were determined using surface tension measurements. These Schiff base surfactants were evaluated for their antibacterial activity against Gram positive and Gram negative bacteria and fungi. The results of the biocidal activities revealed high potent action of the Schiff bases towards bacteria and fungi. The biocidal activity of the tested compounds against sulfur (sulfate) reducing bacteria (SRB) showed promising results in the area of oil field applications.
https://ejchem.journals.ekb.eg/article_1143_931f84378ec312dfa3923096f573687b.pdf
2012-04-30
201
211
10.21608/ejchem.2012.1143
cationic surfactants
Schiff-base
Micellization
Adsorption
Surface properties
Biocidal activity and Sulfate reducing bacteria