Iraqi National Journal Of Chemistry

A computational investigation has been used to chose the best acid which gave the real
concentration of chromium in Certified Reference Material (C.R.M) type (MA-A1) (known
concentration of chromium ) .
A concentration of chromium which obtained from the Atomic Absorption Spectroscopy
(AAS) of (C.R.M) were input using Mathlab Ver.6.1 program and simplex optimization
method .
The program was written and the condition of experiment such as (weight of substance,
type of acid, dilution factor and the response of AAS) were input as a matrix .
In order to reduce the contamination of chromium which come from dust , tow conditions
were input in the program , the first one is the comparison between the real concentration
and the concentration which was obtained from AAS and the second one is to obtain the
smaller concentration of chromium in the substance (C.R.M) .
In this paper the results has been represented by one point on the curve (which is related
to the absolute error as a function of the concentration for each acid ) depend on a such
condition . this curve gave a low absolute error using second order ordinary equation ,
the point showed that the (HClO4:H2O2)(1:1) is the best mixture for chromium analysis. The
computational results showed that its possible to measure concentration of other elements
for different source and hens deferent input conditions depend on such experiment using this
new program.

This work involves the preparation of p-methoxyanisol from methylation of hydroquinone with dimethylsulphate in basic media. Condensation of p-methoxy anisol with benzoic acid or substituted acids in the presence of polyphosphoric acid lead to formation of 2,5-dimethoxybenzophenone and its analogues. Treatment of later compounds that dissolved in methylene chloride with tribromoboron give the corresponded quinols. Moreover, oxidation of quinols with active silver oxide, quinones are obtained.
The synthesized compounds were verified using some spectral data (IR, UV) and C.H.N. analysis

A new method for the determination of Cholesterol in human blood serum based on
Square Wave Voltammetry (SWV) has been described. This method is relay on the decrease
in the reduction peak of 4-aminoantipyrine appeared at (+0.004 V) vs. (Ag/AgC1,3M KCl) as
a reference electrode using Phosphate buffer (pH 7.0) as supporting electrolyte, the method is
sensitive and rapid. The procedure was successfully applied to the determination of
cholesterol in various blood samples represent different cases such as: Hypothyroidism,
Nephrotic syndrome, Obstructive Jaundice & Diabetes Mellitus. The results have been
compared with those obtained from the spectrophotometric method, a good agreement
between the two methods has been obtained with correlation coefficient (r = 0.9986).

2-( 6-Bromo-2-benzothiazolylazo )-4-chloro phenol (6-Br-BTACl) has been synthesized , and
used for the spectrophotometric determination of microgram amounts of copper. This method
sensitive, selective and rapid for reaction between Cu+2 and (6-Br-BTACl), to form a green complex
having a molar ratio of 1:2 (Cu-6-Br-BTACl) at pH 3.7. The molar absorptivity of the complex is
(0.38x104 L.mol-1.cm-1) at λmax 636 nm. Beer’s law is obeyed in the range of 0.05 –1.2 μg.ml-1 and
the stability constant was found to be 3.8x106 L2. mol-2.
The relative standard deviation, recovery and relative error values of method were found to be
R.S.D% = 2.4 , Re % = 96.5 and Erel % = -3.5 . The most important interference were due to Zn2+ ،
Cd2+ ، Hg2+ ، Mg2+ ، Co2+ ، Ag+ ، Pb2+ ، Ca2+ ، CrO4
2- ، Bi3+ ،Ba2+ , WO4
2- ,and Ni2+, and suitable
masking agents were used. The method was applied successfully for determination of copper in the
serum of human blood.

The γ- radiolysis of purines and pyrimidines N2O- saturated aqueous solutions in the presence of either tetranitromethane (TNM) or N,N,N",N"- tetramethyl -P- phenylenediamine (TMPD) has provided information on the yield of both reducing and oxidizing radicals and followed by measurements of G(-chromophore) under various experimental conditions.
The observed yields are attributed to the hydrolysis of intermediate products which can be both base- and acid- catalysed. G(-chromophore) has also been measured. The addition of Cu+ or Cu+ / H2O2 enhances the yields, in the later case by a chain mechanism.

A new Spectrophotometric flow injection method has been established for the determination of Catechol amine drugs (Methyl dopa (I), Adrenaline (II) and Dopamine.HCl (III)). The method is based on the oxidative coupling reaction of Catechol amine drugs with 4-amino antipyrine and sodium hydroxide to form a red-water-soluble stable product, that has a maximum absorbance at 500, 509 and 498 nm for Methyl dopa (I), Adrenaline (II), and Dopamine (III) respectively. Beer's law is obeyed in the range of 5-200, 10-100 and 5-50 μg.ml-1 a limit of detection (signal/noise=3) of 0.75, 0.86 and 0.57 μg.ml-1 for (I), (II) and (III) respectively. The method was applied successfully for the determination of (I), (II) and (III) in pharmaceutical preparation with a good precision and accuracy.

The study was based on extraction of volatile oil which obtained from Iraqi
Thyme ( Thymbra spicata), qualitative identification and quantitative evaluation of
some organic active compounds in the extract oil. The active organic chemical
compounds in the oil extract by Clavenger method, were identified by using Gas
chromatography (GC) The oil were found to contains carvacrol, thymol, p- cymene
and camphor in 29.5%, 0.38%, 5.75% and 0.46% respectively. The compounds were
isolated and identified by Thin Layer Chromatography (TLC), Infrared spectroscopy
(IR) respectively.

Vibration frequencies and IR absorption intensities for the chrysene molecule
in its calculated equilibrium structure were calculated quantum mechanically applying
both the semiempirical MINDO/3-FORCES, the ab initio and density functional
(B3LYP 6-311G) methods. The MINDO/3-FORCES frequency values were scaled
applying scaling factors that had been evaluated formerly for naphthalene, anthracene
and pyrene. Similarly the ab initio frequencies were scaled, and both treatments gave
vibration motions of correct symmetries and sequence in frequency values. The
calculated frequencies of MINDO/3-FORCES and scaled and ab initio methods, were
close to the literature experimental frequencies. The (B3LYP 6-311G) treatment
yielded frequency values that were very close to the experimental and MINDO/3-
FORCES forces frequencies. Comparison of the results for different vibration modes
showed a dependence of the vibration frequencies on the atomic site of the vibration.
Thus the following relations were detected:

Titanium dioxide (TiO2)Was used as photocatalyst for the detoxification of water
containing arsenazo dye(AD) which was degraded under UV radiation source. No,
degradation It was found that for the arsenazo dye in the dark place in the presence of
TiO2.Saveral experiments were performed to optimize the experimental parameters by
employing medium pressure mercury lamp (MPML 125W).Firstly ,it has been found that
best TiO2 mass was 60 mg which gave the highest rate of degradation. The temperature
in the range (283-303) K was studied to evaluate the activation energy of degradation
which was 21.0612 KJ/mole .The effect of PH has been studied over the range
(4,6,8,and 9) . It has been found that the highest degradation rate was at PH=4.

The synthesis of multinuclear heterocyclic system containing substituted 1,3,4-
oxadiazole and 1,3,4-thiadiazole ring was achieved from suitable esters which were
converted to the corresponding acid hydrazides by their reaction with hydrazine
hydrate in ethanol. The treatment of acid hydrazide with phosgene or with carbon
disulfide gave substituted oxadiazole-2-one or 2-thiol respectively. 5-Phenyl-1,3,4-
oxadiazole-2-thiol was treated with 2-chloro-5-phenyl-1,3,4-thiadiazole in ethanolic
potassium hydroxide solution to give (5-phenyl-1,3,4-oxadiazol-2-yl) (5-phenyl-1,3,4-
thiadiazol-2-yl) sulfide, whereas the reaction of 1-[5-(4-aminophenyl)-1,3,4-
oxadiazol-2-yl] hydrazine and
5-(4-aminophenyl)-2-amino-1,3,4-thiadiazole with 5-phenyl-2-chloro-1,3,4-thiadiazole
gave 1-[5-{4-N-(5-phenyl-1,3,4-thiadiazol-2-yl) aminophenyl}-1,3,4-oxadiazole-2-yl] 2-[5-
phenyl-1,3,4-thiadiazol-2-yl] hydrazine and [5-{4-N-(5-phenyl-1,3,4-thiadiazole-2-
yl)aminophenyl}-1,3,4-thiadiazol-2-yl] [5-phenyl-1,3,4-thiadiazol-2-yl] amine
respectively.
The structure of synthesized compounds was established by physical and
spectral means.

In the present investigation, nine novel 2-(aryl)-5-[4-(aroyloxy)phenyl]-1,3,4-oxadiazoles [2-10] were synthesized by a facile one step method through the reaction of 4-hydroxybenzoyl hydrazine with two equivalent of appropriate acid in the presence of phosphorus oxychloride.
Three novel phosphate esters containing three 1,3,4-oxadiazole units [14-16], namely {tri-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]phosphate [14], tri-[4-(5-(p-methoxy phenyl)-1,3,4-oxadiazol-2-yl)phenyl]phosphate [15] and tri-[4-(5-(p-nitro phenyl)-1,3,4-oxadiazol-2-yl)phenyl]phosphate [16]} were also synthesized by one step method through condensation of three equivalent of phenolic compounds [11-13] with phosphorus oxychloride.
All the synthesized compounds were characterized by their melting points and spectral (FT-IR, mass, CHN and UV) data. The newly synthesized compounds were subjected to in vitro against two strains of pathogenic microorganism viz., Staphylococcus arueus and Escherichia coli. The results obtained revealed that compounds [15 and 16] showed considerable activity against Escherichia coli.

Condensation of three equivalents of p-cresol with phosphorus oxychloride afforded tri (p-cresyl) phosphate [1]. Oxidation of the three methyl groups in compound [1] was carried out using potassium permanganate in pyridine yielded tri (4-carboxyphenyl) phosphate [2]. This compound underwent addition– cyclodehydration reactions with 4-methoxybenzoyl hydrazine to produce tri-[4-(5-p-methoxyphenyl-1,3,4-oxadiazol-2-yl) phenyl] phosphate [3].
The 5-(4-hydroxyphenyl)-1,3,4-oxadiazole-2-thiol [5] was obtained by the reaction of 4-hydroxybenzoyl hydrazine [4] with carbon disulfide under basic condition. Reaction of compound [5] with appropriate alkyl halide afforded 5-(4-hydroxyphenyl)-1,3,4-oxadiazol-2-thio alkyl [6 – 8]. Condensation of three equivalents of appropriate phenolic compounds [6 – 8] with phosphorus oxychloride in the presence of pyridine as proton accepter yielded tri-[4-(5-alkyl thio-1,3,4-oxadiazol-2-yl) phenyl] phosphate [9 – 11].
All the synthesized compounds were characterized by their melting points, and spectral (FT-IR, mass, 1H-NMR and UV) data.
The newly phosphate esters synthesized compounds were subjected to in vitro testing against two strains of pathogenic microorganism viz., Staphylococcus aureus and Escherichia coli. The results obtained revealed that compounds [2,9,10 and 11 ] showed considerable activity against the two types of bacteria, while compounds [1 and 3] showed considerable activity against Escherichia coli.

The compound 1 is available, as 1,3,5-triaceytlbenzene, and an efficient trifunctional core reagent for synthesis of dendrimers.
In this study the triseleiolate 3 is treated with benzylic bromide 5 to give the first-generation dendrimer 6. Similarly, the triseleiolate 3 treated with Frèchet,s dendron 7 to give the second- generation dendrimer 8.

Thermoactinomyces sp. was isolated from fermented composed sample. The bacterial isolate was identified according to the cultural, microbiological and biochemical characteristics. The bacterial cells secreted the extracellular protease in alkaline agar medium that contained 1% Hammerstein casein and liquid culture. The enzyme was partially purified 40-fold from culture filtrate by sequential steps including salting out with Ammonium sulfate precipitation (80% saturation) subsequently ion exchange chromatography with DEAE-cellulose column and then CM- Cellulose column which increased the specific activity of the enzyme up to 1880 U/mg proteins with 72% recovery.
Characterization study of the partially purified enzyme was revealed that the enzyme had an optimum activity at pH of 10 and the activity was stable in the alkaline pH range from 8 to 12 for 30 min. Enzyme activity toward casein increased with increasing temperature and the maximal activity at 60 C. The enzyme was stable at temperature under 55˚C and approximately 75% of the activity abolished by incubation of the enzyme at 75  C for 30 min. Alkaline protease activity was completely inhibited by PMSF and DFP; while EDTA showed no inhibition on protease activity that is suggested that the enzyme is a serine protease.