Co(II), Ce(III) and UO2(VI) bis-salicylatothiosemicarbazide complexes

Synthesis, characterization, mass spectral fragmentation, thermal study and biological evaluation of new Schiff base ligand and its metal(II) complexes derived from 4-(diethylamino)salicylaldehyde and thiazole moiety

“…The enhancement in the antimicrobial activity may be rationalized on the basis that ligands mainly possess azomethine (C=N) bond. Moreover, in metal complex, the positive charge of the metal ion is partially shared with the hetero donor atoms (N and O) present in the ligand and there may be π-electron delocalization over the whole chelating system [38]. Hence the increase in the lipophilic character of the metal chelates favour their permeation through the lipoid layer of the bacterial cell membranes and blocking of the metal binding sites in the enzymes of microorganisms.…”

Synthesis, Characterization, Electrochemical Behaviour, DNA Binding and Cleavage Studies of Substituted β-DiketimineCopper(II) and Zinc(II) Complexes

“…The spectra of free ligands show a band in the region 1630-1610 cm -1 characteristics of the (C=N) stretching mode [7] indicating the formation of the Schiff base products. This band is shifted towards lower frequency by ca.20 cm −1 on complexation compared to free ligands indicating the involvement of the azomethine nitrogen in chelation with the metal ion, the coordination of the nitrogen to the metal ion would be expected to reduce the electron density of the azomethine link and thus causes a shift in the (C=N) group [8]. Coupled with this, the absence of a band around 1641-1730 cm -1 [21], characteristic of ν(-C=O) in 3-(3-phenyl-allylidene)-pentane-2,4-dione, suggests that the condensation of the keto groups is complete.…”

Synthesis, Characterization and Antimicrobial Activities of Hydrazone Ligands Derived from 2-(phenylamino)acetohydrazide and Their Metal Complexes

“…35 The infrared spectra of the uranyl complexes 4, 7, 16 and 19 reveal bands in the 940-954 cm -1 range which may be attributed to ν(O=U=O). 36,37 The spectra of vanadate complexes 11 and 23 show bands at 3325, 1418 and 3300, 1432 cm -1 attributed to the NH stretching and deformation of NH 4 + group respectively. In addition bands in the 977-946 cm -1 assigned to ν(V=O).…”

“…17 The appearance of a new bands appeared in the ranges 504-692 and 420-534 cm -1 for different complexes may be assigned to the ν(MO) and ν(MN) respectively. 27,28 The ν as (CO respectively. In unidentate acetate complexes ν(C=O) is higher than ν s (CO…”