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Toplam kayıt 676, listelenen: 1-20
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Synthesis of new lariat cyclicdiamides and their metal complexes
(Editura Stiintifica F. M. R., 1996)Three new lariat dilactam host molecules were prepared by the reaction of triethyleneglycol dicarboxylic acid dichloride with N,N′-disubstituted-4,7-dioxa-1,10-diazadecane precursors. The amide nitrogen pivot of such ... -
Flame AAS determination of platinum, palladium, and rhodium in catalysts
(Perkin-Elmer Corp, 1997)A flame atomic absorption spectrometric method is described for the determination of platinum, palladium, and rhodium in used and fresh alumina-supported and sieve catalysts. A lanthanum solution was used to eliminate ... -
Investigation of suitable digestion methods for the determination of total phosphorus in soils
(Elsevier Science Bv, 1997)Total phosphorus in five soils with different compositions which were obtained from different places were extracted by using Na2CO3 fusion, HClO4 digestion, HClO4 + HNO3 digestion, HF + HClO4 digestion or NaOBr oxidation ... -
Electrokinetic properties of perlite
(Academic Press Inc Jnl-Comp Subscriptions, 1997)Electrokinetic properties of expanded and unexpanded perlite samples have been investigated using the microelectrophoresis technique. Perlite samples yield practically no isoelectric point in the pH range of 3 to II. Both ... -
Thermal behaviour of some metal complexes of N,N-diethyl-N'-benzoyl thiourea
(John Wiley & Sons Ltd, 1997)The thermal behaviour of the complexes of N,N-diethyl-N'-benzoylthiourea (DEBT) with NI(II), Cu(II), Pt(II), Pd(II) and Ru(III) was studied using differential thermal analysis (DTA) and thermogravimetry (TG). These complexes ... -
The determination of crown-cation complexation behavior in dioxane/water mixtures by conductometric studies
(John Wiley & Sons LTD, 1998)Using conductance measurements, an attempt has been made to gain detailed information about the specific molecular interactions of crown compounds with metal ions in a 1,4-dioxane/water binary system. Analyses of the ... -
Surface titrations of perlite suspensions
(Academic Press Inc, 1998)The surface charge behaviour of unexpanded and expanded perlite samples in KNO3 and NaCl solutions were investigated as a function of pH and ionic strength. The solutions of KNO3 and NaCl ranging from 10(-3) to 1.0 M were ... -
Dyeing of modified cotton fibres with disperse dyes from supercritical carbon dioxide
(Soc Dyers Colourists, 1998)Cotton, previously modified by reaction with benzoyl chloride and sodium benzoylthioglycollate, was dyed with disperse dyes APAN and DY82 in supercritical carbon dioxide at 100 degrees C and 300 bar. This process is compared ... -
The synthesis of novel crown ethers. Part IV. Coumarin derivatives of [18]crown-6 and cation binding from fluorescence spectra
(Editura Stiintifica F. M. R., 1998)4-H, 4-methyl and 4-phenyl-1-benzopyran-2-one derivatives of [18]crown-6 derivatives were synthesised from 6,7- and 7,8-dihydroxy-1-benzopyran-2-one reacting with pentaethylene glycol ditosylate in K2CO3/DMF/water. The ... -
The association constant of macrocyclic ether-cation interactions in 1,4-dioxane/water mixtures. III - Effect of temperature on the binding
(Wiley-V C H Verlag Gmbh, 1999)The association constant, K-a, of Na+ with [12] crown-4, [15]crown-5 and [18]crown-6 crown ethers were determined in a binary mixture, 1,4-dioxane/water (50/50) using a Na+ ion selective electrode at different temperatures. ... -
Estimation of Li+, K+ and Ca2+ complexation with [12]crown-4, [15] crown-5 and [18]crown-6 using a Na+ISE in dioxane-water, part IV - Cation equilibrium constants of macrocyclic ethers with ion selective electrodes
(Springer-Verlag Wien, 1999)The (1:1) Na+ equilibrium constants, K-e1, of macrocyclic ethers of [12]crown-4, [12]crown-5 and [18]crown-6 were determined with a Na+ ISE in the presence of a second cation e.g. Li+, K+ and Ca2+ in dioxane/water (50/50). ... -
Phosphonate-based resins for the selective enrichment of uranium(VI)
(Elsevier Science Bv, 1999)Phosphonate-derivatized polystyrene-divinylbenzene-based (PS-DVB) resins have been prepared from chloromethylpolystyrene-divinylbenzene (Cl-CH(2)-PS-DVB) by the Arbuzov-reaction using lithium or sodium alkyl chlorophosphites. ... -
Solvent effect upon ion-pair extraction of different sodium dyes using some crown ethers
(Springer, 1999)Liquid-liquid extractive-spectrophotometric studies of sodium ion complexes of 18-crown-6(18C6), dibenzo-18-crown-6(DB18C6), 15-crown-5(15C5), and 12-crown-4(12C4) and anionic dyes [4 (2 pyridylazo)-resorcinol monosodium ... -
Study of the thermal decompositions on N,N-dialkyl-N '-benzoylthiourea complexes of Cu(II), Ni(II), Pd(II), Pt(II), Cd(II), Ru(III) and Fe(III)
(Kluwer Academic Publ, 1999)The thermal decompositions of the complexes of N,N-dialkyl-N'-benzoylthioureas with Cu(II), Ni(II), Pd(II), Pt(II), Cd(II), Ru(III) and Fe(III) were studied by TG and DTA techniques. These metal complexes decompose in two ... -
The synthesis of novel macrocycles, Part V. The coumarin crown ethers and cation binding with fluorescence spectra
(Gordon Breach Scı Publ Ltd, 1999)The 4-H, 4-methyl and g-phenyl derivatives of benzo-alpha-pyrone of 12-crown-4 and 15-crown-5 were synthesised starting from 4-substituted-6,7-dihydroxy- and 7,8-dihydroxybenzo-alpha-pyrones which reacted with dichloropolyethylene ... -
The synthesis of novel crown ethers, part VII [1]. Coumarin derivatives of benzocrowns and cation binding from fluorescence spectra
(Springer, 2000)4-[3-(1-benzopyran-2-one)] derivatives of benzo[12]crown-4, benzo[15]crown-5 and benzo-[18]crown-6 were synthesized from 4-[3-(1-benzopyran-2-one)]-1,2-dihydroxy-benzene reacting with bis-ethyleneglycol dihalides or ... -
Thermal decomposition kinetics of some metal complexes of N,N-diethyl-n '-benzoylthiourea
(Kluwer Academic Publ, 2000)Thermogravimetry (TG) and differential thermal analysis (DTA) were performed on the complexes with general formula (M(DEBT)(n) (where M=Fe, Co, Ni, Cu or Ru; n=2, or 3 and DEBT=N,N-diethyl-N'-benzoylthiourea). Derivative ... -
Extraction of some transition metals with N,N-dibutyl-N '-benzoylthiourea into molten paraffin at 65 degrees C
(Elsevier Science Bv, 2000)The solid-liquid extraction behaviour of some transition metals (Cu(II), Co(II), Ni(II), Cd(II) and Pb(II)) by the use of N,N-dibutyl-N'-benzoylthiourea as an extractant in paraffin (58-60 degrees C) has been investigated ... -
Determination of acidity constants of acid-base indicators by second-derivative spectrophotometry
(Pergamon-Elsevier Science Ltd, 2000)A method for calculation of acid-base dissociation constants of monoprotic weak organic acids whose acid and base species have overlapping spectra from absorptiometric and pH measurements is described. It has been shown ... -
Adsorption of methylene blue from aqueous solution onto perlite
(Kluwer Academic Publ, 2000)Adsorption of methylene blue from aqueous solutions onto unexpanded and expanded perlite samples activated by H2SO4 and NaCl solutions has been investigated, to assess the possibility of using perlite for removing cationic ...
