a series of new heteroleptic chelated copper(ii) complexes that encompass n,n-dibezyl substituted derivative of ethylenediamine (x-diamine) and acetylacetonate (acac) were prepared.  the ir and electronic absorption spectra and the molar conductivity of the complexes are presented and discussed.  the molar conductivity values of the complexes in different solvents reveals a predominance of elec...

The very sensitive, fairly selective direct spectrophotometric method for the determination of trace amount of vanadium (V) with naphthalene -1, 5 -diamine has been developed. Naphthalene -1, 5 -diamine reacts in slightly acidic (0.0001– 0.001 M H2SO4 or pH 4.0–5.5) alcohol media with vanadium (V) to give a red–violet chelate which has an absorption maximum at 531 nm. The stoichiometric composi...

In the title compound, [CrF(C(8)H(20)N(4))(H(2)O)](ClO(4))(2)·H(2)O, the Cr atom is in a slightly distorted octa-hedral environment, coordinated by four N atoms of the 4,7-diaza-decane-1,10-diamine ligand, one water mol-ecule and an F atom trans to water. The five-membered chelate ring is in a gauche form, while the two six-membered chelate rings are in chair conformations. The crystal structur...

The lipophilicity of a series of Schiff base ligands and their complexes with nickel(II) and copper(II) has been determined by reversed-phase thin-layer chromatography using binary dioxane-water mobile phase. Chelate ligands were prepared by condensation of diamine and the corresponding beta-diketone. Copper(II) and nickel(II) complexes with chelate ligands containing ethane-1,2-diamine or prop...

The synthesis of the new potentially hexadentate ligands N,N'-bis(2,2'-bipyridin-6-ylmethyl)butane-1,4-diamine (bmbu), N,N'-bis(2,2'-bipyridin-6-ylmethyl)pentane-1,5-diamine (bmpt) and N,N'-bis(2,2'-bipyridin-6-ylmethyl)octane-1,8-diamine (bmot) from the condensation of 2,2'-bipyridine-6-carbaldehyde with the appropriate diamine (butane-1,4-diamine, pentane-1,5-diamine and octane-1,8-diamine, r...

the kinetics of the de complexation by hydroxyl ions of some pervanadyl, molybdate and tungstate amionocarboxylate complexes have been studied spectrophotometrically by means of a stopped flow technique. the chelate groups used were the iminodiacetic acid (ida), ethylenediarnine-n,n' -diacetic acid (edda), nitrilotriacetic acid (nta) and ethylene diamine-n,n,n' ,n'-tetraacetic ac...

In the title mononuclear complex, [Pt(CH(3))Cl(C(45)H(41)N(3)P(2))], the pyridine-2,6-diamine ligand can be viewed as a centrosymmetric motif having two pendant N-benzyl-N-[(diphenyl-phosphan-yl)meth-yl] arms, the two P atoms of which chelate to the Pt(II) ion, forming a ten-membered metallocycle. A distorted square-planar coordination geometry around the Pt(II) atom is completed by a methyl li...

Although paraCEST is a method with immense scope for generating image contrast in MRI, it suffers from the serious drawback of high detection limits. For a typical discrete paraCEST agent the detection limit is roughly an order of magnitude higher than that of a clinically used relaxation agent. One solution to this problem may be the incorporation of a large payload of paraCEST agents into a s...