Complexation of some antibiotics with lanthanum [III]

The interaction of La [III] with some selected antibiotics e.g. ampicillin, cephalexin, cephradine, oxytetracycline and tetracycline were studied by potentiometric or pH titrations. The stability constants of different binary complexes formed in such system have been determined at 25 +/- 0.1 and an ionic strength [M] of 0.1 mol. 1-1 by using the computer program Miniquad. The results showed the formation of 1: 1 complexes together with the corresponding hydrolyzed species. The solid complexes were separated and their composition and structure were confirmed by elemental analysis, IR spectrometry and conductometric measurements. The results showed that the beta-lactam antibiotics act as bidentate ligands, coordinated to the La [III] through the amino and the carbonyl-groups of side chain

Metal complexes of triazole-2-yl thiourea: synthesis, characterization and equilibrium studies

Triazoles have been reported to be biologically versatile compounds, having bactericidal[1], fungicidal [2] insecticidal[3] and pesticidal[4]properties, also thiourea. Frequently display a wide biocidal activities [5,6]. It is well known that certain metal complexes have greater activity than the coordinating agents themselves [7] This has led us to study in the present work a new thiourea derivative having a triazole moiety with some transition metal ions, in continuation to previous studies on thiourea complexes[8]. The present investigation comprises l-triazole-2-yl-3-benzoyl- thiourea, BTu, and some of its metal complexes. The composition and structure of the formed complexes have been characterized by elemental analysis, potentiometric titrations, electrolyte conductance, IR, electronic and proton NMR spectrometry and magnetic susceptibility measurements

Polarographic and spectrophotometric behaviour of some aminoazole derivatives

The structure of differently substituted azole amines is receiving considerable interest [1,3] but the structure of aminoisoxazolnes has seldom been adequately investigated. Literature inspection reveales that only few 3-amino-isoxazolones have been synthesised. Elnagdi et al [4] described the synthesis of 5- amino - 4- arylhydrazono-1,2 oxazole-3- ones [1] and their isomeric 3- amino-4- arylhydrazono-l,2-oxazole-5- ones [2]. However, the structure of these isoxazolone derivaties have not been exclusively defined. In conjunction with any investigation aiming to test the potential of the above compounds as dyes and precursors in dye synthesis, better understanding of the structure of these compounds seemed to be of value. In the present work, the polarographic behaviours of compounds [1] and [2] studies and pK values are calculated, to get insight into the nature of the various tautomeric structures of [1] and [2] their electroreduction in alcoholic buffered media covering a wide range of pH

Electrochemical behavior of the product of coupling of crotononitrile with aryldiazonium salts

It has been reported that compounds la-c couple with aromatic diazonium salts to yield the corresponding hydrazones 2a-c, which readily cyclize into the pyridazines 3a-c, c.f. Plate 1. However, Mittelbach [1] reported that at least the product of coupling component 1 c with aromatic diazonium salts would be 3 c, so that compound 2 c could have never been isolated. This led Mettelbach [1] to suggest that the coupling products assigned by Elnagdi et al. [2] as being of the types of compound 2 would be in fact related to compounds 3

Metal chelates of 3-amino-2-substituted crotononitrile

Synthetic heterocyclic organic chemistry involves specially designed reagents which are readily generated and then used to provide molecules built-in functional moieties usually utilized several applications. Important examples of such reagents are Beta-amino crotononitrile which have been proven to be valuable in the synthesis of a wide variety of unique heterocyclic systems such as pharmaceuticals, fungicides and solvatochromatic dyes [1-4]. It is known that metal complexes have greater activity than the coordinating agents themselves [5]. Synthesis and characterization of solid complexes of several transition metal cations were the primary concern of our earlier work [6-15]. However, it seems that no studies have been made on the complexes of compound [I] in the solution phase or in the solid state, which will be investigated in the present study. Conductometric, spectrophotometric measurements are used for characterization of some of these complexes as well as elemental analysis, magnetic measurements and spectral [electronic, IR] studies. The mechanism of the chelation process will also be investigated for each of the different ions used