New copper(II) complexes of 2-hydroxyacetophenone N(4)-substituted thiosemicarbazones and polypyridyl co-ligands: structural, electrochemical and antimicrobial studies

Copper(II) complexes derived from di-2-pyridyl ketone-N4-phenyl-3-semicarbazone: Synthesis and spectral studies

“…In the chloro complex 1, a shoulder observed at 23,300 cm −1 is assigned as Cl → Cu charge-transfer transition [32]. All the complexes gave d-d bands in the 14,950-16,000 cm −1 range [33,34]. For the Cu(II) complexes there are three spin allowed transitions, A 1g ← B 1g , B 2g ← B 1g and E g ← B 1g , but it is difficult to resolve them into separate bands due to the very low energy difference between these bands.…”

Synthesis, characterization and physiochemical information, along with antimicrobial studies of some metal complexes derived from an ON donor semicarbazone ligand

“…The charge transfer bands are observed ∼25,000 cm −1 [23] and their broadness can be explained as being due to the combination of O → M and N → M LMCT transitions. The spectra of the complexes 1, 2, 3, 4 and 6 exhibit weak d-d bands in the range 13, 700-16, 670 cm −1 [24,25]. Representative spectrum of the semicarbazone ligand HL is presented in Fig.…”

Copper (II) complexes of sterically hindered o-diphenol derivatives: synthesis, characterization and microbiological studies

“…At the same time the free ligand III shows no appreciable activity against Candida utilis or Candida boidinii (MIC>125 µg·mL −1 ), while its Cu (II) complex exerts a pronounced antimicrobial effect (MIC=62.5 µg·mL −1 ). According to [62], a better membrane penetrating ability explains the frequently observed cases when complexes are more effective against the yeasts than the free ligands. It has also been supposed [62] that the reduced activity of the compounds against yeasts can be attributed to their inability to form hydrogen bonds with cell constituents.…”

“…According to [62], a better membrane penetrating ability explains the frequently observed cases when complexes are more effective against the yeasts than the free ligands. It has also been supposed [62] that the reduced activity of the compounds against yeasts can be attributed to their inability to form hydrogen bonds with cell constituents.…”