NOPR Collection:

UV-visible spectroscopic study of preferential solvation of N-alkylpyridinium iodides in mixed binary solvents containing benzene

1995-05-01T00:00:00Z

Title: UV-visible spectroscopic study of preferential solvation of N-alkylpyridinium iodides in mixed binary solvents containing benzene Authors: Laha, Ashis Kumar; Banerjee, Debashis; Bagchi, Sanjib Abstract: The UV-visible absorbance wavelength maximum of N-ethyl-4-cyanopyridinium iodide and N-ethylpyrazinium iodide has been utilised to investigate the solvation characteristics of the solute in fourteen binary mixed solvents containing benzene. The observed preferential solvation (PS) of the indicator solute by the polar cosolvents has been explained in terms of various interactions present in the system using the existing models for PS. The PS parameters characterising various interactions have been calculated. Page(s): 335-341

Removal of some anionic and cationic detergents using an inorganic gel adsorbent

1995-05-01T00:00:00Z

Title: Removal of some anionic and cationic detergents using an inorganic gel adsorbent Authors: Srivastava, S K; Gupta, V K; Anupam; Mohan, Dinesh Abstract: The uptake of two cationic detergents, cetyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB) and two anionic detergents, sodium dodecylsulphate (SDS) and sodium dodecylbenzenesulphonate (ABS) has been observed on copper ferrocyanider which is prepared and characterised by well known methods. Sorption data have been correlated with both Langmuir and BET adsorption models. The presence of mono and divalent cations increase the uptake of ABS and SDS and the enhancement is much more in the presence of trivalent salt like AlCl₃• Thermodynamic parameters indicate the feasibility of the process while kinetic measurements provide the necessary mechanistic information. Desorption of anionic detergents from loaded copper ferrocyanide has also been achieved. Page(s): 342-350

Os(VIII) catalysed oxidation of phenyl styryl ketone and substituted phenyl styryl ketones by periodate: Interactive free energy relationship

1995-05-01T00:00:00Z

Title: Os(VIII) catalysed oxidation of phenyl styryl ketone and substituted phenyl styryl ketones by periodate: Interactive free energy relationship Authors: Padmaja, S; Rao, K Nageswar; Rao, M Prasad; Sethuram, B Abstract: Kinetics of Os(VIII) catalysed oxidation of phenyl styryl ketone and its substituted analogues by periodate has been investigated in acetic acid + dichloromethane + water medium in the temperature range 298-313 K. The rates are found to be enhanced by electron releasing substituents and retarded by electron withdrawing substituents both in benzaldehyde and acetophenone rings. However, the effect of substituents is more pronounced when they are present in benzaldehyde ring. The magnitude of P_X(Y) value obtained from the slope of Hammett's plot for various substituents in benzaldehyde moiety decreases with the introduction of electron withdrawing groups in acetophenone moiety and vice versa. A linear plot is obtained between P_X(v) and s_y, (substituent constant for substituent in acetophenone moiety) with a slope of 0.36 ± 0.01. The plot of P_y(x) (obtained from Hammett's plot for various substituents in acetophenone moiety) versus s_x (substituent constant for substituent in benzaldehyde moiety) is also linear with a slope of 0.41 ± 0.01. The results have been analysed in terms of interactive free energy relationship. Page(s): 351-354

Synthesis of novel 16- and 18-membered tetraazamacrocycles and their coppertll), cobalt(II) and nickel(II) complexes

1995-05-01T00:00:00Z

Title: Synthesis of novel 16- and 18-membered tetraazamacrocycles and their coppertll), cobalt(II) and nickel(II) complexes Authors: Shakir, Mohammad; Varkey, Saji P Abstract: The tetraamide macrocycles of the type L₁-L₂ have been synthesized by the condensation reaction of phthalic acid with primary diamines which on reduction with LiAlH₄ yields their corresponding tetraazamacrocycles L₃, and L₄, The Co(II), Ni(ll) and Cu(II) complexes of these ligands have been synthesized and characterized by elemental analysis, mass, IR, ¹H NMR, EPR and electronic spectroscopic techniques as well as molar conductance and magnetic moment data. An octahedral geometry around the metal ion is suggested for [ML₃X₂]- [ML₄X₂l [where M = Co(II) and Ni(II); X = Cl or NO₃] while a square planar geometry is proposed for [ML₃]X₂ - [ML₄]X₂ [M = Cu(II); X=Cl or NO₃]. Page(s): 355-359