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

Copper (II) Acylhydrazinates. Their Synthesis and Characterization

“…In the spectra of the Cu(II) complexes (Table III), these proton signals appeared much more downfield, as expected, due to increased 28 29 conjugation during coordination [14][15][16][17][18] (64-82 %); +++% [18][19][20][21][22] (82-100 %). Percent inhibition values are relative to inhibition zone (22 mm) of the most active compound with 100 % inhibition.…”

Organometallic compounds with biologically active molecules: in vitro antibacterial and antifungal activity of some 1,1′‐(dicarbohydrazono) ferrocenes and their cobalt(II), copper(II), nickel(II) and zinc(II) complexes

“…It has been suggested that ligands with nitrogen and oxygen donor systems inhibit enzyme activity, since the enzymes that require these groups for their activity appear to be more susceptible to deactivation by the metal ions on coordination. Moreover, coordination reduces the polarity 34,35 of the metal ion mainly because of the partial sharing of its positive charge with the donor groups 36 -39 within the chelate ring system formed during coordination. This process, in turn, increases the lipophilic nature of the central metal atom, which favours its permeation more efficiently through the lipoid layer of the micro-organism, 40 -43 thereby destroying them more aggressively.…”

New antimicrobial agents: The synthesis of Schiff base polymers containing transition metals and their characterization and applications

“…The 1 H‐NMR spectra of the polymeric Schiff base in DMSO‐ d 6 exhibited a resonance signal at 11.9 ppm, which was assigned to the phenolic OH protons 39. The aromatic proton showed multiple resonance signals between 6.67 and 7.93 ppm for the polymeric Schiff base and polymer–metal complex of Zn(II) 40. The methyl proton attached to the 2‐ hydroxyl acetophenone was observed at 1.39 ppm.…”