Chromium(III) and iron(III) perchlorate with the mono-N-oxides of 2,2′-bipyridine and 1,10-phenanthroline

Spectroscopic characterization of some metal complexes derived from 4-acetylpyridine nicotinoylhydrazone

“…spectra of Zn II and Cu II complexes show that (4-APNH) behaves as mononegative bidentate ligand coordinating through carbonyl oxygen in the enol form and azomethine nitrogen ( Figure 5). This behavior is supported by the following evidences: ( [16,17].…”

Synthesis, characterization, molecular modelling and biological activity of 2‐(pyridin‐1‐ium‐1‐yl) acetate and its Cu2+, Pt4+, Pd2+, Au3+ and Nd3+ complexes

“…). The mode of coordination is confirmed by the following evidence: (i) the shift of the band due to ν(CO) vibration indicating the involvement of this group in bonding while the bands in the range 1103–1156 cm −1 assignable to ν(C―O) vibrations remain unshifted after coordination; (ii) the IR spectra of the complexes show a broad medium band in the range 3414–3451 cm −1 attributable to water of coordination as well as the water and/or ethanol of solvation; and (iii) the suggested mode of coordination for the aforementioned complexes is also confirmed by the appearance of new bands at 527–573 cm −1 attributable to ν(M―O) vibration . The most important assignments of IR bands are listed in Table .…”

Synthesis and characterization studies of new five member ring metal chelates derived from benzion phenoxyacetyl hydrazone(H2BPAH)

“…In Compound alcoholic also shifts to a lower wavenumber and (iv) the appearance of new bands at 512-513 and 449-471 cm À1 regions assigned to t(M-O) (Speca et al, 1974) and t(M-N) (Beecroft et al, 1974), respectively.…”

“…This mode of complexation is supported by the following evidences. (i) t(C‚N) shifts to a lower wavenumber, (ii) the disappearance of d(OH), (iii) t(C-O) (Lal et al, 2001) alcoholic shifts to a lower wavenumber indicating the probable participation of the oxygen in coordination, (iv) t(C‚O) appears in the same position at 1692 cm À1 as observed in the free ligand, suggesting that the carbonyl oxygen (C‚O) does not take part in coordination and (v) the appearance of new bands at 508 and 473 cm À1 assigned to t(Pd-O) (Speca et al, 1974) and t(Pd-N) (Beecroft et al, 1974), respectively.…”

“…The IR spectrum of [Cd(H 2 BPAH)Cl 2 ] shows that H 2 BPAH behaves as a neutral bidentate ligand, coordinating through the carbonyl oxygen (C‚O) and azomethine (C‚N) nitrogen forming a five membered ring including the cadmium atom. This mode of chelation (structure II) is supported by the following evidences: (i) both t(C‚O) and t(C‚N) shift to a lower wavenumber, (ii) The stretching vibration of the (OH) group appears as a strong band in the high frequency regions at 3632 cm À1 indicating the non-involvement of the OH group in bonding (Abu El-Reash et al, 1988); and (iii) the appearance of new bands in the low frequency region at 544 and 514 cm À1 assigned to t(Cd-O) (Speca et al, 1974) and t(Cd-N) (Beecroft et al, 1974), respectively. The IR spectrum data of [Pd(HBPAH) 2 ] show that H 2 BPAH behaves as a mononegative bidentate ligand which coordinates via the azomethine nitrogen (C‚N) and the oxygen atom of the deprotanted alcoholic forming a five membered ring including the palladium atom as shown in structure III.…”