SYNTHESIS AND CHARACTERISATION OF SOME NICKEL(II)β-KETOAMINES AND THEIR ADDUCTS WITH 2,2′-BIPYRIDINE AND 1,10-PHENANTHROLINE

Abstract

A series of nickel(II) b-ketoimine complexes, {Ni[CH 3 -C(O)CHC(CH 3 )NR] 2 , R CH 3 , C 4 H 9 }, and ketoiminates, {Ni[CH 3 C(O)CH(CH 3 )C(-N(CH 2 ) n N-)C(CH 3 )CHC(O)CH 3 ], n 2, 6, 8, 9}, and their adducts with 2,2 H -bipyridine (bipy) and 1,10-phenanthroline (phen) have been synthesized and characterized using elemental analyses, magnetic susceptibility, conductivity, infrared and electronic spectral measurements. The ketoimine ligands coordinate to the nickel atom in a bidentate fashion using the N 2 O 2 chromophore. A range of stereochemistries was observed for the nickel(II) ketoiminates from four-coordinate tetrahedral and square-planar geometry to six-coordinate octahedral geometry. Conductivity

Synthesis, characterization and biological studies on unsymmetrical Schiff-base complexes of nickel(II), copper(II) and zinc(II) and adducts with 2,2′-dipyridine and 1,10-phenanthroline

“…The involvement of the phenoxide O in bonding was confirmed by the disappearance of the (OH) band, observed at 3454 cm -1 in the ligand, in the complexes. A new (OH) band was, however, observed in Schiff-base complexes 1049 [15][16][17]. These bands were shifted to 1607-1458 cm -1 upon coordination, thus confirming the involvement of the azomethine N in coordination to metal(II).…”

“…The mixture was refluxed for 2 h and the product formed was filtered, washed with ethanol and dried over anhydrous calcium chloride. A similar procedure was used to prepare the other 2,2 0 -bipyridine and 1,10-phenanthroline adducts [15][16][17].…”

“…Other Schiff-base complexes of non-cyclopentadienyl semiquinone and aminoacids are of particular interest due to their catalysis and may serve as models for biological studies [8][9][10][11]. There are many symmetrical Schiff-base complexes [12][13][14], and their pyridine, 2,2 0 -bipyridine and 1,10-phenanthroline adducts [15][16][17] reported in the literature. Literature is building on complexes of unsymmetrical Schiff bases [18][19][20][21].…”

<b>Studies on some VO(IV), Ni(II) and Cu(II) complexes of non-symmetrical tetradentate Schiff-bases</b>

“…These ligands are widely studied because of their pronounced coordinating properties and stability [8][9]. A number of symmetrical Schiff bases and chelates have been reported [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15], while comparatively little is known on synthesis and physico-chemical properties of asymmetric Schiff-base ligands and metal complexes [16][17][18][19][20]. Consequently, the aim of this work is to synthesize and characterize unsymmetrical Schiff-base ligands (derived from condensation of 1-phenyl-1,3-butanedione/2,4-pentanedione, ethylenediamine and 5-methoxy-2-hydroxy acetophenone) and their VO(IV), Ni(II) and Cu(II) complexes, in order to see the effect of the mixed π-electron ligand system and phenyl/methyl substituent on geometries and physico-chemical properties.…”

Coordination Polymeric Assemblies of some d‐Block Elements with Schiff Bases and its Characterization

“…The electronic spectra of the coordination polymers have been studied in the solid state between 350 to 1700 nm. The electronic spectra of the Ni(II) coordination polymers (19) exhibit three bands at 10,550, 17,000 and 25,000 cm 21 , which may be due to the transitions 3 A 2g (F) ! 3 T 2g (F) (n 1 ), 3 A 2g (F) !…”