Synthesis and characterization of cobalt(II), nickel(II), copper(II), palladium(II) and dioxouranium(VI) complexes of the antipyrine Schiff base of 3-formylsalicylic acid

Abstract

A new Schiff base has been synthesized from 4-aminoantipyrine and 3-formylsalicylic acid. The ligand has a dianionic tetradentate compartmental OONO donor system. The cobalt(II), nickel(II), copper(II) and dioxouranium(VI) complexes exist in phenolato-bridged dinuclear species, while palladium(II) gives a mononuclear complex with free ACOOH groups. The complexes have been characterized by elemental analyses, i.r., u.v.-vis, thermal and magnetic measurements.

Synthesis, spectroscopic investigation and biological activity of metal complexes with ONO trifunctionalalized hydrazone ligand

“…4 A 2g and 4 T 1g (F) ! 4 T 2g (F), transitions respectively, corresponding to high spin cobalt(II) octahedral complexes [43,52]. Complex (8) shows bands at 215, 320, 410, 480 and 545 nm.…”

Ni(II), Cu(II), and Zn(II) complexes of tetradentate schiff base containing two thiadiazoles units: Structural, spectroscopic, magnetic properties, and molecular modeling studies

“…Schiff base complexes containing different central metals such as Co, Ni, Cu, and Zn play a central role as chelating ligands in main group and transition metal coordination chemistry [1][2][3][4]. Transition metal complexes of tetradentate Schiff base ligands have been used as model analogues of certain metal enzymes [5][6][7], in catalysis and material chemistry [8][9][10][11], in various other fields such as illness treatment, biochemical reaction, and biological regulator [12], and have specific activities in pharmacology and physiology. Furthermore, the 1,3,4-thiadiazole ring system is known to possess several biological activities SCHEME 1 Synthetic route to Schiff base ligand (3).…”

Synthesis, characterization, electrical and catalytic studies of some coordination compounds derived from unsymmetrical Schiff base ligand

“…Also, the absence of a new band at 850-950 cm -1 in Zr(IV) complex due to (Zr=O) stretch. The MoO 2 (VI), UO 2 (VI), WO 2 (VI) complexes show new bands around 956, 960, 943 cm -1 due to  asym (O=Mo=O),  asym (O=U=O) and  asym (O=W=O) vibrations [21]. The WO 2 (VI) complex shows bands around 2063 (CN), 776 (CS) and 468 cm -1 (NCS) suggesting that the thiocyanate group act as ligand in which bonding through nitrogen takes place [22].…”