JOURNAL OF SCIENCES (ISLAMIC AZAD UNIVERSITY)
Year:2007 | Volume:17 | Issue:64 (CHEMISTRY ISUE)|Papers Count:9

Rotational spectra of the symmetric top molecule CF3CCD have been measured in its vibrational ground states. Analysis of the vibrational ground - state spectra gave the following rotational parameters such as B0=2696.06753 MHz, DJ=0. 22759 kHz, DJk=6.1748 kHz. The HJk =16.1 mHz and HkJ=- 0.24.3 mHz were determined for the first time. Contribution of individual constants to frequency has been discussed.

Imide acid derivatives are an important class of substrates for biological and chemical applications. In the chemical applications they are used for synthesis of new amino acid derivatives and peptides. In this paper rapid and highly efficient synthesis of six optically active imide-acid derivatives 4(a-f) was achieved under microwave irradiation by using a domestic microwave oven from the reactions of six different chiral a-amino acid 2(a-f) with phthalic anhydide 1 in the presence of small amount of N,N-dimethyl formamide (DMF) as a base. The reaction proceeded rapidly (100-150 sec), and as a result a series of chiral imideacid derivatives 4(a-f) were obtained in high yields (96-100%). All of the synthesized compounds were fully characterized by their melting point, specific rotations, elemental analyses, 1H-NMR and FT-IR spectroscopy.

Direct Blue 86 (DB86), commonly used as a textile dye, can be degraded photocatalyticaly in aqueous solutions using TiO2 suspensions. A 400 W UV-A lamp was used in a batch circulating photo-reactor, without any dead zone. An initial concentration of 50 mg/L of dye, as a typical concentration in textile wastewaters, was used and the influence of catalyst concentration, pH and temperature were investigated. The experiments showed that degradation of dye can be effectively occurring in the both branches of photolysis (only UV) and photocatalysis (UV/TiO2). Accordingly, the optimum operating conditions of: catalyst concentration: 40 mg/L, pH of 4 and temperature of 40oC were obtained. Under these conditions, a degradation of about 96% and a mineralization of about 87% (based on COD measurements) of dye were achievable during about only 120 min.

It’s been years that zeolites are known as effective materials in the world. A zeolite is a crystalline, hydrated aluminosilicate of alkali and alkaline earth According to the special impact of these materials, by the general formula: Mx/n [(Al2O3)x (SiO2)y].WH2O We are focusing on their usage in agricultural soils .In this paper beside of reviewing some of the other writings based on usage of zeolite in agricultures, we focus on "Cation Exchange Capacity" of different modes and comparing them to zeolites and the amount of trans passing Ammonium cation from modes which near of the roots of plant in terms of irrigation time. Based on accomplished experiments advantages of using natural zeolite to amend the agricultural soils in order to improve the ability of up keeping nitrogen in the form of ammonium and prevention of its loss because of irrigation and rain, economize amount of consuming water and prevention of wasting the beneficial substances of soil because of the high cation exchange capacity is to be studied. Zeolite that used is natural zeolite which called "Clinoptilolite". This zeolite is selected because of two special factors: 1 - existence in Iran 2 - high Cation Exchange Capacity specially for Ammonium and Potassium And finally we try to introduce some ways for using this zeolite to amend the agricultural modes.

In this work, we have focused on study of swelling kinetics and salt-sensitivity behavior of a superabsorbing hydrogel based on carboxymethylcellulose (CMC) and polyacrylonitrile (PAN). The physical mixture of CMC and PAN was hydrolyzed by NaOH solution to yield hydrogel, CMC-poly (sodium acrylate-co-acrylamide). The swelling kinetics of the hydrogels with various particle sizes was preliminary investigated as well. The swelling of the hydrogel showed a second order kinetics of swelling in water. In addition, swelling measurements of the synthesized hydrogels in various chloride salt solutions was measured. Results indicated that a swelling-loss with an increase in the ionic strength of the salt solutions.

In this investigation for preparing triscyclopentadienillanthanids such as Samarium (Sm), Neodymium (Nd), Gadolinium (Gd) and Ytterbium (Yb) have been done experiment with different reaction of the lanthanide chlorides with sodium cyclopentienide in tetrahydrofuran solution. The complex was prepared in three steps. Purification was done by sublimation compounds at 200-250°C in vacuum. Magnetic moment for prepared complexes with theoretical method have been calculated and campared with datas by Gouy apparatus. calculated magnetic moment for tris (cyclopentsdieny 1) lanthanides Ne, Sm, Gd, Yb were continuously 1.65 ,7.94, and 4.5 (B.M) and measured moment magnetic were continuously 1.62, 8.86 and 4.81(B.M). Great difference between calculated and measured magnetic moment for Samarium can be related in increasing paramagnetic characteristic of complex.For recognizing of this complexes, the elemental analysis and (FT-IR) spectrua have been used.

A new adsorptive anodic differential pulse stripping voltammetry method for the direct determination of riboflavin at trace levels in human plasma is proposed. The procedure involves an adsorptive accumulation of riboflavin on a hanging mercury drop electrode (HMDE), followed by oxidation of adsorbed riboflavin by voltammetry scan using differential pulse modulation. The optimum conditions for the analysis of riboflavin are pH=6.5 using borate buffer, accumulation potential of -700 mV (vs. Ag/AgCl), and accumulation time of 70 s. The peak current is proportional to the concentration of riboflavin, and a linear calibration graph is obtained at 0.01-0.90 mgml-1. A relative standard deviation of 0.52% (n= 3) was obtained, and the limit of detection was 6 ngml-1. The capability of the method for the analysis of real samples was evaluated by determination of riboflavin in spiked human plasma with satisfactory results.

A method describe for cleaning up morphine from plasma using a liquid-liquid extraction with THF followed up solid-phase extraction with NaY zeolite. Samples were extracted using zeolite NaY column followed by reversed phase HPLC with fluorescence detection. Morphine has shown to have a retention time of 9.45 min using a mobile phase of water, methanol and acetonitrile at Ex=235nm, Em=349nm wavelengths. The total recovery of extraction was 107±12.7%. This method was based on an ex-calibration procedure and was linear between 20- 200 ng/ml of morphine. The lowest amount of morphine in plasma, which can be determined by this method, was 10ng/ml.