ABSTRACT
In the title compounds, [2,2'-[2,2-dimethyl-1,3-propanediylbis(nitrilomethylidyne)]diphenolato-kappa4N,N',O,O']nickel(II), [Ni(C19H20N2O2)], and [2,2'-[2,2-dimethyl-1,3-propanediylbis(nitrilomethylidyne)]diphenolato-kappa4N,N',O,O']copper(II), [Cu(C19H20N2O2)], the Ni(II) and Cu(II) atoms are coordinated by two iminic N and two phenolic O atoms of the N,N'-bis(salicylidene)-2,2-dimethyl-1,3-propanediaminate (SALPD2-, C17H16N2O2(2-)) ligand. The geometry of the coordination sphere is planar in the case of the Ni(II) complex and distorted towards tetrahedral for the Cu(II) complex. Both complexes have a cis configuration imposed by the chelate ligand. The dihedral angles between the N/Ni/O and N/Cu/O coordination planes are 17.20 (6) and 35.13 (7) degrees, respectively.
ABSTRACT
In the title linear trinuclear compound, [Zn[Zn(CH(3)COO)(C(17)H(16)N(2)O(2))](2)], the central Zn(2+) ion, which is located on an inversion centre, has a distorted octahedral coordination involving four bridging O atoms from two N,N'-bis(salicylidene)-1,3-propanediaminate ligands in the equatorial plane and one O atom from each bridging acetate group in the axial positions. The coordination around the terminal Zn(2+) ion is irregular square pyramidal, with two O and two N atoms of the ligand in the basal plane and one O atom from an acetate group in the apical position. The acetate bridges linking the central and terminal Zn(2+) ions are mutually trans. The Zn.Zn distance is 3.0520 (8) A. The relationship of this structure to that of [Zn[Cu(CH(3)COO)(C(17)H(16)N(2)O(2))](2)] is discussed.
ABSTRACT
A new nitrate-selective liquid-membrane electrode based on the tris(2,2',2"-salicylideneimino)triethylamine-iron(III) complex has been developed. This electrode exhibits a linear Nernstian response over the range 10(-1)-10(-4) M of nitrate, with a slope of 54.3 +/- 0.9 mV per p[NO3]. The effects of the pH and the liquid-membrane composition were also investigated. The lifetime of the electrode is at least one month. The selectivity coefficients for ten monovalent ions were calculated. The preparation procedure of the electrode is very easy and inexpensive. Moreover, the proposed electrode was applied for the determination of nitrate in fertilizers.
ABSTRACT
In the mononuclear title compound, [ZnCl(2)(C(14)H(13)NO)(2)], the Zn(II) ion is located on a twofold axis of the monoclinic space group so that the whole molecule has a twofold symmetry. The Zn(II) ion has a tetrahedral coordination consisting of two chlorine ions and the O atoms of the ligands. The coordination angles around zinc have values between 102.89 (8) (O-Zn-O) and 115.83 (5) degrees (Cl-Zn-O). The Zn-O and Zn-Cl bond lengths are 1.977 (2) and 2.2401 (7) A, respectively. There are intra- and intermolecular hydrogen bonds in the structure.
ABSTRACT
A potentiometric titration method in non-aqueous media is proposed for the determination of some commonly used anti-inflammatory agents. The direct potentiometric titration of three anti-inflammatory agents, namely mefenamic acid, fenbufen and ibuprofen; and the indirect potentiometric titration of diclofenac sodium was carried out in acetonitrile solvent using tetra-n-butylammonium hydroxide as titrant, at 25 degrees C and under a nitrogen atmosphere. The method was found to be highly accurate and precise, having a relative standard deviation of <1.0% for all anti-inflammatory agents studied. Also, it was shown that the method could be successfully applied to the assay of commercial pharmaceuticals containing the above-mentioned anti-inflammatory agents. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the results were found to be satisfactory. The proposed method is simple, rapid and sufficiently precise for quality control purposes.
