VOLUME 7, NO3, SEPT 1985

Factors Governing the Herbicidal Properties of Paraquat, I,ll-Dimethyl Bipyridylium Dichloride

The factors .earlier proposed as being probably responsible for the herbicidal activi~~f paraquat (l,l'dimethyl bipyridylium dichloride) family were re-examined in the light of the existence of the higher reduction product MB: and the relative rates of the reaction of the two reduction.products of MB~+ with oxygen. Since in the case of paraquat it has earlier been proposed that adsorptivity may be a factor which influences its herbicidal activity, the reaction of the two reduction products MB. and MB: with oxygen were studied in adsorbed state. The role of MB: is thus highlighted in the present study.read more

---

M MOHAMMAD ,R JAHAN ,R IQBAL ,A Y KHAN ,K ZAHIR ,

Complexes of VOSO 4 with Multidentate Schiff Base Ligands

The present communication deals with the preparation and character­isation of complexes of multidenti\te schiff base ligands with VOS04. The complexes possess 1:1 stoichiometric ratio (Metal: ligand). In all the com­plexes the sulphate ion is coordinated in a bidentate manner with C2v symmetry. The complexes possess C4v or D4h symmetry with coordination number five and are highly distorted. There is sufficient degree of overlap between metal and ligand orbitals.read more

---

M U RAHMAN ,N AHMAD ,M ATTAR ,

Kinetics of Oxidation of L-Arginine and L-Histidine By Sodium N-Chloro-4-Methylbenzenesulphonamide, (Chloramine-T) in Alkaline Medium

The kinetics of oxidation of L-arginine and L-histidine by chlora­mine-T in alkaline media showed a first-order dependence of the rate on both chloramine-T and amino-acid concentrations, with no effect of change in ionic strength. The rate of reaction decreases as the pH is increased over the range 10 to 12. The energies of activation were found to be 65.3 and 51.8 kJ mol , and the entropies of activation -84.7 and -124.6 J K mol ,for arginine and histidine respectively. The effect of solvent has also been studied, and evidence is presented that the main mechanism of reaction is by interaction of the anion of the amino acid with the RNHCl species of chlora­mi ne- 1. The fract i ona 1 order of react i on wi th respect to [OH -] is probably due to involvement of OC1-, which is present in low concentration.read more

---

K C GUPTA ,K K GUPTA ,

Physicochemical Studies On The System Uranyl-Gallic Acid in Aqueous Solutions

Spectrophotometric, potentiometric and polarographic studies were carried out in the system uranyl-gallic acid in aqueous solution of different pH values. Composition and stability of the complex formed are determined by spectrophotometric and potentiometric method. The polarographic behaviour of the di fferent complexes was studi ed and the effect of gall i c aci d on the reduction of U(VI) was discussed.read more

---

Y M ISSA ,G A EL INANY ,F ZAIDAN ,B EL SHETARY ,

Spectral and Magnetic Properties of Some Cobalt(II) Cyanide Complexes

ln contrast to aqueous preparative procedures, the liquid ammonia preparations of cobalt(II) cyanide conform to an exact CN/Co stoichiometry of 2:1. The ammonium analogue of Adamson's salt, (NH4)6[C02(CN)1O]' which is readily prepared in this medium also yields Co(CN)2 upon thermal decom­position. The preparation and properties of the complexes K [(Co(CN)3] and K2 [(Co(CN)4] are described and their structures discussed.read more

---

D M S MOSHA ,

Isolation, Purification and Partial Characterization of a Glycoprotein from Plasma Secretion

The antigenic polymers present in seminal plasma playa key role in the processes of reproduction, survival of cells and provide genetic markers. A high molecular-weight glycoprotein component has been isolated from seminal plasma, purified and its partial structure has been investigated by lectin affinity and haemagglutination inhibition. A possible function of this glyco­protein has been discussed.read more

---

M S AJAZ ,K MALGHANI ,M AYAZ ,N U DIN ,E W NASIR ,

Kinetics of Silver Catalyzed Aquation of Chloropenta-Amminecobalt (III) Perchlorate at 50°C

The silver ion induced aquation of [Co(NH3)SC1] (C104)2 has been carried out at SO°C and constant ionic strength (0.80 M). The rate of re­C[Ag]a + [Ag] o and b take the values of SO and 6.3 respectively. Suitable mechanism has been proposed to explain the kinetic data and the significance of the empirical constants a and b are discussed.read more

---

N H ESMAIL ,M F AMIRA ,N H EL HAMMAMY ,M M ELSEMONGY ,

A Convenient Synthesis of 6,12-Disubstituted Chrysenes

6,12-Dimethylchrysene has been synthesised, by photo-oxidative cyclization of 2-methyl-l-[a-(4-methylnaphthyl)] -2-phenylethene. Similarly, irradiations of 2-methyl-l-[a-(4-methoxynaphthyl)]-2-phenylethene,2-cyanO-l-[a -(4-methylnaphthyl)]-2-phenylethane and 2-cyano-l-[a-(4-methoxynaphthyl)]­2-phenylethene yielded 6-methoxy-12-methyl.6-cyano-12-methyl and 6-cyano-12­methoxychrysenes respectively. No migration of substituents was observed.read more

---

I S AL SHIEBANI ,F S KAMOUNAH ,

Synthesis and Reactions of Some 4-(3-oxo-I,3-diaryl¬propyl) -l-phenyl- 3, 5-pyrazolidinediones

Pyrazolidinedione derivatives (II) are prepared through the hitherto unknown nucleophilic addition of l-phenyl-3,5-pyrazolidinedione to chalcones (I). Reactions of II with phenylhydrazine, hydrazine hydrate, hydroxylamine hydrochloride and aromatic amines afford the corresponding phenylhydrazones, diazepene derivatives, oximes and arylidene derivatives. Behaviour of II towards polyphosphoric acid, Grignard reagents, phosphorus pentasulphide and acetylating agent has also been investigated.read more

---

M EL MOBAYED ,N AHMED ,G H SAYED ,A A HAMED ,

Indirect Atomic Absorption Spectrophotometric Method For the Determination of Nitrate

An indirect atomic absorption spectrophotometric method for the determination of 0.5 - 5 ~moles nitrate is described. The method is based on the formation of insoluble ternany complex, [Ag(Phen)2]N03 ' by adding an excess of [Ag(Phen)2] solution in nitrate sample. Absorbance of un reacted silver ions has been measured in an air-acetyl ene fl ame. The effect of various ions has been investigated. The method is successfully employed for the determination of nitrate in fertilizer samples.read more

---

T U HAQUE ,J ANWAR ,