Synthesis and spectroscopic studies of new binuclear transition metal complexes of Schiff bases derived from 4,6-diacetylresorcinol

Abstract

Two new series of copper(II), nickel(II), cobalt(II), zinc(II), iron(III), chromium(III), vanadyl(IV) and uranyl(VI) complexes with two bifunctional tridentate Schiff base, H 4 L 1 and H 2 L 2 ; ligands have been prepared. The Schiff base, H 4 L 1 and H 2 L 2 , ligands were synthesized by the condensation of 4,6-diacetylresorcinol with o-aminophenol or o-phenylenediamine. The ligands are either di-or tetra-basic with two symmetrical sets of either OON or NNO tridentate chelating sites. The ligands and their metal complexes have been characterized by elemental analysis, 1 H-n.m.r., FT-IR, mass, electronic, esr spectra and thermal gravimetric analysis and magnetic susceptibility. With the exception of Co II ion with H 2 L 2 which afforded a trinuclear complex, a variety of binuclear complexes for the rest of the metal complexes were obtained with the ligands in its di-or tetra-deprotonated forms. The bonding sites are the azomethine and amino nitrogen atoms, and phenolic oxygen atoms. The metal complexes exhibit different geometrical arrangements such as square planar, tetrahedral, square pyramid and octahedral arrangement.

Transition metal complexes of Schiff base ligand based on 4,6‐diacetyl resorcinol

“…The spectrum of free ligand (H 2 L) exhibited a signal at 8.41 ppm region, which may be assigned to thiazole protons (s, 1H). In the aromatic region, two singlet signals observed at 6.38 and 6.06 ppm (s, 2H, Ar‐H) …”

Functional Hybrid Materials Based on Layered Simple Hydroxide Hosts and Dicarboxylate Schiff Base Metal Complex Guests

“…Typical spectra of the hybrid compounds, the complex, and the hydroxide precursors are presented in Figure 4. [70][71][72][73][74][75][76] After the exchange reaction, the spectra of all the hybrids indicate the almost complete disappearance of the very strong CH and CH 2 absorption bands at ν = 2925 and 2854 cm -1 and the vanishing of the -SO 3 or -SO 4 bands at ν = 1300-1000 cm -1 arising from the dodecyl sulfate or dodecyl sulfonate in the copper or cobalt hydroxide precursors, respectively. Assignments were made by comparison with the literature.…”

Preparation, spectral characterization and antimicrobial activity of binary and ternary Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Ce(III) and UO2(VI) complexes of a thiocarbohydrazone ligand

“…However, it was not possible to identify the type of the d-d transition. This is due to a strong charge transfer (CT) band tailing from UV-region to the visible region [40,41]. The effective magnetic moment values of the complexes (2)(3)(4) are in the range 4.8-5.5 B.M., Table 3, which are lower than the expected value of the high-spin octahedral arrangements, suggesting an antiferromagnetic interaction [42,43].…”