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The proton donor-acceptor complexes formed by 1,3-disubstituted halopropane 2-ols with tetrahydrofuran (THF) and triethylamine (TEA) in carbon tetrachloride solution have been studied. The area of the OH-stretching band corresponding to the intermolecularly H-bonded complexes was plotted against concentration of THF to determine the relative strength of H-bonding. The equlibrium constant and the frequency shifts were calculated. The equilibrium constants for the 1:1 complexes between alcohols and the base are in the order Br < Cl < F.read more
SHAHIDA SHAMIM ,MANSOOR AHMAD ,QADAR SHARIF ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 1
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Densities were determined for the binary and ternary mixture of the alcohols and triethylamine in CCl4 and cyclo-C6H12 at 298 K. From the experimental results, the excess molar volume (VM(E)) were calculated. VM(E) are positive for binary mixtures of the alcohols in both, CCl4 and cyclo-C6H12. But for ternary mixture (in CCl4), the excess molar volumes are negative in the low concentration range of the alcohols. The difference has been explained in terms of interstitial accomodation of the solvent and possible H-bond interaction of the type OH...Cl between the components of the system. Besides, positive excess molar volumes are higher for 2-haloethanols than those for ethanol. These high values have been attributed to the substitution of hydrogen atom by halogen atoms.read more
SHAHIDA SHAMIM ,MANSOOR AHMAD ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 4
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The presence of six organochlorine pesticides has been studied in rain-water, tap-water and underground-water of Karachi. The probable sources of these insecticides in the atmosphere and water arc discussed.read more
MOHD SAEED ALAM ,ZAHID BEGUM ,SAEEDAN BEGUM ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 8
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The preparation of the complexes Zn(Mn) (L-His)2 and Cd(Mn) (L-HiS)2 are reported . The E.S.R. spectra, at both X- and Q-band of Mn(II) ions doped in these complexes and also those of M(L-His)2.2H2O (M = Zn and Cd) are reported, and the zero-field splitting parameters D and (lambda = E/D) are deduced. Considerably higher values of D and lambda observed for M(Mn) (L-His)2.2H2O (M = Zn and Cd) suggest quite appreciable deviation from regular symmetry as would be expected from their crystal structure studies [1-2]. The distinctly lower values of D and lambda observed for anhydrous complexes, M(Mn)(L-His)2 (M - Zn and Cd), suggest geometries tending, most probably, towards regular octahedral structures. The negative sip of D observed from the Q-band spectra of these complexes, suggests that the principal D-tensor axis lies along the line of two Cd-N bonds, and the coordinated oxygens from the carbonyl groups are in cis-positions.read more
MARGARET GOODGAME ,IZHAR HUSSAIN ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 11
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The copper(II) and nickel(II) complexes of new tetradentate ligands bis (acetylacetone)ethylmethylethylenediimine (H2AA2EMen), bis(trifluoroacetylacetone)ethylmethylethylenediimine (H2F3AA2EMen) and bis(trifluoroacetylmesityloxide)ethylmethylethylenediimine (H2F3AM2EMen) have been prepared and characterized using IR H-1-NMR and mass spectroscopic techniques. ne reagents and metal complexes have been examined spectrophotometrically and the effects of complexation, solvent and fluorosubstitution on the absorptiometric properties have been reported.read more
M Y KHUHAWAR ,A G BHATTI ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 14
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Different species of Fe(III)-galic (FeHL, FeL2, FeL3) acid complexes are formed at different pH values These species have different rates of reduction with ascorbate. By measuring the overall rates of reduction of Fe(III) to Fe(II) at different pH and using the calculated species distribution at the corresponding pH a graphical procedure was applied to obtain the bimolecular rate constants for reduction of indivudal complex species. These were k(FeHL) = 87.9, k(FeL) = 113 and k(FeL2) = 4 all in units of M-1S-1.read more
S ARIF KAZMI ,ZAHIDA T MAQSOOD ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 20
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6-Chloro-2-methyl-4-H-1-benzopyran-4-one (1) gave the isoxazole derivative (2a) on reaction with hydroxylamine hydrochloride. The action of hydrazine and phenylhydrazine on (1) resulted in pyrazole derivatives (3a) and (3b) respectively. The reactivity of (1) with ethyloxalate and aromatic nitroso compounds have been investigated. Phthalide (8a) derived from the chromone (1) was synthesised and rearranged easily into 1,3-indandione (9) upon refluxing with alcoholic sodium methoxide. Cleavage of (8) with amines and hydrazine hydrate was studied. Thiation of phthalide (8a) with either Lawesson's re-agent or phosphorous pentasulphide yielded the corresponding thione (8c)read more
ASHRAF A AHMED ,MOUNIR A I SALEM ,ALI G EL SHEKEIL ,HASSAN M F MADKOUR ,A S BABAQUI ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 24
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The dienes CH2=C(CH2Cl),CMe=CH2 (3), CHCl=CMe.CMe=CH2 (4), CHCl = CMe. CMe = CHCl (14), and CHCl = C(CH2Cl). CMe = CH2 (21) have been synthesised via chlorination of 2,3-dimethylbuta- 1,3-diene. Copper-catalysed addition of benzenesulphonyl chloride to 2,3-dimethylbuta-1,3-diene and diene (3) gives the 1,4-adducts PhSO2. CH2. CMe = CMe. CH2Cl and a mixture of PhSO2.CH2.C(CH2Cl)-CMe.CH2Cl and PhSO2. CH2. CMe = C (CH2Cl)2, respectively. Dehydrochlorination of the former adduct gives the diene PhSO2CH = CMe.CMe = CH2 which polymerises in air. Dienes (4) and (21) form Diels-Alder adducts with tetracyanoethylene. Chlorination of diene (14), is surprisingly accompanied by addition of hydrogen chloride and gives the compounds CHCl2.CClMe.CClMe.CH2Cl and CHCl2.CCl(CH2Cl). CClMe.CH2Cl. The dichloride CH2Cl. CMe = CMe. CH2Cl reacts with an equimolar amount of bromine by addition, but with an excess of bromine the products are CH2Br.C(CH2Cl) = C(CH2Cl).CH2Br(89%) and (CH2Br)2C = C(CH2Cl).CH2Br (6%). Unexpected substitutive bromination is observed on treatment of the trichloride (CH2Cl)2C=CMe.CH2Cl with bromine to give (CH2Cl)2 C = C(CH2Cl).CHzBr (95%).read more
ANTHONY E TIPPING ,ALBERT C PRATT ,MOHAMMAD A BIGDELI ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 35
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Beta-Aroylacrylic acids (1a-d) react with primary amines and secondary amines to give the corresponding alpha-alkylamino-beta-propionic acids (2a-r) and (3 a-h). Treatment of (2c) and/or (2e) with acetic anhydride gave the butenolide (4) and the ketone (5). Reaction of (4) with phenylhydrazine gave the phenylhydrazone (6). Reaction of (2e) with hydrazine and/or phenylhydrazine gave the pyridazinone derivatives (7a and b).read more
M A SAYED ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 45
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2,4-Dichlorobenzoic acid reacts with chlorosulphonic acid to yield the corresponding sulphonyl chloride (1). Subsequent condensation with nucleophiles afforded sulphonyl derivatives (2-11), which are used for the synthesis of methyl esters (12-18), the corresponding hydrazide (19-22) and the dipeptide derivatives (23-36). The spectral data of the synthesized compounds (2-36) and the results of preliminary biological screeing are briefly discussedread more
RAGAB A EL SAYED ,M F BADIE ,F A KORA ,N S KHALAF ,
- 24 May 2011
- Volume Detail: VOLUME 14, NO1, MAR 1992
- Pages: 49
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