Iranian Journal of Chemistry and Chemical Engineering
Volume:18 Issue: 1, May-Jun 1999

The essential oils of Zataria multiflora (Labiatae) from four regionsof Iran were investigated by GLC and GC-MS methods. The main constituents werecarvacrol, thymol, linalool and p-cymene. The percentage of the constituents (indry and wet plant) of different regions have been compared. Antibacterial andantifungal effects of these essential oils have been studied. The essential oil withhighest percentage of thymol and carvacrol had a significant antimicrobial activity.

A highly selective, rapid and economical differential pulsepolarographic method has been developed for the determination of trace amountsof cadmium and lead present together in various standard alloys and biologicalsamples after adsorption of their 1-(2-pyridylazo)-2-naphthol complexes onmicrocrystalline naphthalene. Cadmium and lead complexes are equantitativelyadsorbed on microcrystalline naphthalene in the pH range of 8.2-11.0 forcadmium and 8.4-11.5 for lead. After filtration, the solid mass is shaken in 10mL of 1 M hydrochloric acid and these metals are determined simultaneously bydifferential pulse polarography (DPP). Detection limits are: 0.07 mg/mL for Cdand 0.1 mg/mL for Pb (signal to noise ratio=2). While linearity is maintained inthe concentration range 0.1-150 mg/mL for Cd and 0.1-300 mg/mL for Pb with acorrelation coefficient of 0.9996 and relative standard deviations of 0.98 and1.1%, respectively. Various parameters such as the effect of pH, volume ofaqueous phase and interference of a number of metal ions on the determinationof cadmium and lead have been studied in detail to optimize the conditions fortheir simultaneous (based upon the difference in their Ep values) determination incomplex materials.

4-(4-Nitrophenyl-azo)-2-(2-Methoxy phenimino)-phenol and its coor-dination compounds with Ni(II), Cu(II), Co(II) and Fe(III) have been synthe-sized and characterized by elemental analyses, FT-IR, Far-IR, Near IR, UV-Vis,Mass Spectrometry and Molar Conductivity and their electrochemical behavioursare reported.

5-((4-alkoxyphenyl)azo) salicylaldehyde, 5-((4-alkoxyphenyl)azo)-N-(npentyl, ndodecyl)-salicylaldimine and bis[5-((4-alkoxyphenyl)azo)-N-(npentyl,ndodecyl)- salicylaldiminato]copper(II) [alkoxy=O nCnH2n+1; n=3-7] homologueswere synthesized and characterized by elemental analyses, mass and IR spectra.All complex homologues are thermally stable. Cyclic voltammetric studies indica-ted that all copper complex homologues have a quasi-reversible redox wave andpeak current ratio (ipa/ipc) decreasing with increase of alkyl chain length.

The cyclization of b-anilino propionic acids in the presence of polyphosphoric acid (PPA) afforded the 2,3-Dihydroquinoline-4-(1H)-ones in good yields. N,N''-bis(2-carboxyethyl)-4-methyl-1,2-diaminobenzene (7) is cyclized under this condition to produce the 1,5-diaza-2,3,6,7-tetrahydro-4-methyl-pheranthrene-4,8-dione(bis-quinolone) (8).

Effects of imidazoles and substituted pyridines and pure s-donorson the oxidation of cyclooctene with NaIO4 by 5,10,15,20-tetraphenylporphyrinato-manganese(III) acetate, Mn(TPP)OAc, and 5,10,15,20-tetramesitylporphyrinato-manganese(III) acetate, Mn(TMP)OAc, catalysts in CH2Cl2-H2O solvent arestudied. Coordination of the nitrogen donors to the Mn-catalysts generally caused areduction in the epoxidation rates, and an increase in their stabilities towardoxidative degradation. Steric properties of the donors rather than their basicityseems to be more dominating in these oxygenation reaction. The bulky Mn(TMP)OAcshowed a greater steric sensitivity than Mn(TPP)OAc.

An efficient synthesis of 3-substituted or 2,3-disubstituted 4(3H)-quinazolinones from benzoxazin-4-ones and primary amines under microwaveirradiation in unsealed vessels is described.

Addition of potassium cyanide to a mixture of Schiff base and lithiumperchlorate afforded a-aminonitriles in high yields. Addition of potassium cyanideto a methanolic solution of Schiff base and phosphoric acid afforded a-amino-nitriles. When the reaction mixture was refluxed it gave a-amino acids in high yields.

The reaction of tertiary, secondary and benzylic alcohols withdifferent nitriles in the presence of alumina-methanesulfonic acid (AMA) as anew reagent affords the corresponding amides in good yields (Table 1, 2).Convertion of 2,6-bis(hydroxymethyl)-4-halo anisoles into corresponding diamidesin the range of 68-76% yields (Table 3) are also included in this paper.

A classical theory is developed which calculates the momentumtransfer rate constant between an ion and a non-polar molecule. The model takesinto consideration the effect of diffraction outside the capture limit on the rateconstants. The theory is used to calculate momentum transfer rate constant forCl- with trans-dichloroethylene and para-difluorobenzene. Theoretical results arecompared to those predicted by the Langevin model and also with the experi-mental data. It is shown that the inclusion of diffraction outside the capture limitincreases the theoretical momentum transfer rate constants. It is suggested thatother potential terms may be important in determining momentum transfer rateconstants for these systems.