Rudong Yang

Crystal structure and antitumor activity of some rare earth metal complexes with Schiff base

Abstract The ligand 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone (PMBP) isonicotinoyl hydrazone (H2L) was prepared by condensation of PMBP with isoniazid. Seven complexes of rare earth metals with H2L were synthesized and characterized on the basis of elemental analyses, IR, UV, 1H NMR spectra and thermal analyses. The general formula of the complexes is Ln(HL)3·3.5H2O (where Ln(III)=La, Eu, Gd, Tb, Dy, Ho and Er). X-ray diffraction analysis showed that the coordination polyhedron of the Eu complex is a tricapped trigonal prism. The La and Eu complexes possess antitumor activity, and the inhibitory rates for leukemia cells (L1210) are 87.1% and 78.5%, respectively.

Synthesis and crystal structure of a barium complex with pyruvic acid isonicotinoyl hydrazone

Abstract A barium complex with pyruvic acid isonicotinoyl hydrazone (H 2 L) has been synthesized and its crystal structure was determined by X-ray diffraction analyses. There is one complex unit, Ba(HL) 2 (H 2 O), with eight lattice water molecules in the asymmetric unit. The nine-coordinated barium has a distorted, monocapped square antiprism configuration.

Synthesis and crystal structure of the dinuclear complex of 6-methylpicolinic acid N-oxide with lanthanum(III)

Abstract A new dinuclear complex of 6-methylpicolinic acid N -oxide (6-mepicno) with lanthanum(III) ion, La 2 (6-mepicno) 6 ·6H 2 O, was synthesized and characterized by elemental analysis, molar conductance, thermogravimetric analysis and IR spectra. The structure of the complex was determined by single-crystal X-ray diffraction. In the complex, the two lanthanum(III) ions were coordinated by six 6-mepicno and two water molecules, and the coordination number of the lanthanum(III) ion is nine. However, the 6-mepicno adopted different coordination modes, acting as both chelating bidentate and bridging bidentate ligands. The coordination polyhedron is a distorted tricapped trigonal prism. The LaO bond lengths are in the range of 0.2441(2)–0.2760(2) nm.

Synthesis of ion association complexes of lanthanide ions with 1,5-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,5-pentanedione and cetyltrimethyl ammonium bromide and their UV, IR, 1H NMR, fluorescence and thermal analysis studies

Abstract The preparation of 13 novel solid ion associated complexes of lanthanides with 1,5-bis(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,5-pentanedione (denoted BPMPPD) and cetyltrimethyl ammonium bromide (noted CTAB) is reported. IR, 1 H NMR, UV, fluorescence spectra and thermogravimetric data have been recorded and discussed. The composition of these complexes is determined as CTA[Ln(BPMPPD) 2 ] (where CTA = cetyltrimethyl ammonium cation; Ln = Y, La, Pr, Nd, Sm—Yb), and a structure is suggested.

Synthesis of novel mixed-ligand complexes of lanthanide ions with 1,4-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,4-butanedione and 1,10-phenanthroline and their UV, IR, 1H NMR, fluorescence and thermal analysis studies

Abstract The synthesis of 14 mixed-ligand solid complexes of lanthanide ions with 1,4-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,4-butanedione (BPMPBD) and 1,10-phenanthroline (PHEN) in an alcohol—water solution is presented. The comosition of the complexes is determined as Ln 2 L 3 P 2 · n H 2 O (Ln = Y, La, Pr, Sm—Lu; L = BPMPBD; P = PHEN; n = 4,5) by chemical and elemental analyses. The complexes are regarded as binuclear and characterized by IR, UV, 1 H NMR, fluorescence spectra, thermoanalysis and conductance methods.

Studies on the stabilization of terbium(IV) in aqueous tetrametaphosphate solution

Abstract Terbium(IV) was obtained by oxidation of trivalent terbium in an alkaline aqueous solution of sodium tetrametaphosphate with ozone. The concentration of terbium(III), the pH and the temperature of the solution all greatly affected the generation and stabilization of terbium(IV). Studies showed that the reduction of terbium(IV) (presumably by water) in alkaline solution was a pseudo first-order reaction. The characteristic absorption spectrum, the molar absorptivity, the rate constants and the activation energy of the reduction reaction of terbium(IV) are reported.

Chelate complexes of 1,3-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,3-propanedione and 1,10-phenanthroline with lanthanide

Abstract A new ligand, 1,3-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,3-propanedione (H2L), and its chelated complexes, Ln2L3(Phen)2·nH2O (where Phen = 1,10-phenanthroline, Ln = lanthanide and Y, n = 3–6), have been prepared by the reaction of H2L and Phen with the relative metal nitrate in an aqueous alcoholic solution. The binuclear structure of the complexes is proposed according to the discussions of the elemental analyses, molar conductance, IR and 1H NMR spectra. Fluorescence spectra prove Pr, Sm, Eu, Tb, Dy and Tm complexes have line emissions of metal ions.

Studies on the synthesis and crystal structure of a magnesium complex with pyruvic acid isonicotinoyl hydrazone

Abstract A magnesium complex with pyruvic acid isonicotinoyl hydrazone (H2L), having the general formula [MgL(H2O)31 · H2O, has been synthesized and its crystal structure determined by X-ray diffraction analyses. The structural parameters and typical IR spectra bands for H2L complexes with Mg and other metals are discussed.

Investigation on lanthanide binuclear complexes of 1,5-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,5-pentanedione and 2,2′-bipyridine

Abstract The coordination of 1,5-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,5-pentanedione (BPMPPD) and 2,2′-bipyridine (bipy) with lanthanide ions in water-alcohol solution has been studied. Binuclear complexes of the types : Ln2(BPMPPD)3(bipy)2·nH2O (n = 2 for Y, n = 4 for Eu, Gd, Dy, Ho, Er, Tm and Yb); Ln2(BPMPPD)3bipy·nH2O (n = 10 for La, n = 3 for Pr, Nd, Sm and Tb) were formed. The compounds were characterized by elemental analysis, molar conductance, IR, UV, 1H NMR spectroscopy, thermogravimetric analysis and fluorescence spectra.

Study of the complexing of lanthanide ions with 1-phenyl-3-methyl-4-heptaflurobutyryl pyrazolone-5 and triphenylphosphine oxide by the two-phase titration method

Abstract The reaction of rare earth ions with l-phenyl-3-methyl-4-heptaflurobutyrylpyrazolone-5 (PMHFP) and triphenylphosphine oxide (TPPO) in water-chloroform was studied by two-phase titrations. The compositions and stabilities of the complexes obtained are discussed. Stability constants of the complexes (β302), dissociation constants (pKa), two-phase dissociation constants (pKae) and two-phase distribution coefficients (pKd) of the chelating agent PMHFP were also determined.