Complexes of NS and NSO donor ligands. Nickel(II), copper(II) and cobalt(II) complexes of glyoxal bis(morpholineN-thiohydrazone) and diacetyl bis(morpholineN-thiohydrazone)

SYNTHESIS AND CHARACTERIZATION OF Zn(H) COMPLEXES WITH SOME ACYLHYDRAZINE SCHIFF BASES

“…Instead, a band due to v(C-O) at about ~1335 cm" 1 was observed for all the title complexes, which supported the observation of their enolization during coordination. These facts suggested that the Schiff base remains in the keto tautomeric form in the solid state whereas in solution, both the keto and enol foims seem to be in equilibrium 19 (Fig. 2) and during complexation, deprotonation occured at the enolic form.…”

Synthesis and characterization of mononuclear copper(II) and cadmium(II) complexes with di-(2-picolyl)sulfur

“…The divalent and trivalent transition metal complexes with NNS and NNN donor ligands have been of great interest because of their importance as an analytical chelate reagent, biological and bacteriostatic activity [1][2][3][4][5][6][7][8][9][10][11]. Of these, the structures of the copper(II) and cadmium(II) complexes have already been determined by single-crystal X-ray diffraction.…”

Antibacterial Schiff Bases of Oxalyl-hydrazine/diamide Incorporating Pyrrolyl and Salicylyl Moieties and of Their Zinc(II) Complexes

“…The absence of the OH band at , 3315 due to the salicylyl moiety in Schiff bases L 3 and L 4 and appearance of a new band instead at 1245 cm 21 indicated deprotonation and coordination through oxygen. Furthermore, the appearance of a weak, low frequency new band at 445 and 515 cm 21 was assigned 21,22 to metal-nitrogen n(M -O) and n(M -N) vibrations. These bands were only observable in the spectra of the metal complexes and not in the spectra of their Schiff bases, which in turn, confirmed the participation of the heteroatom (NH) and deprotonated (OH) in the coordination.…”