Synthesis and characterization of ferrocenylcarbaldehyde benzoylhydrazone and its rhenium(I) complex

Synthesis and characterization of several rhenium(I) complexes of 2-acetylpyridine and ferrocenyl carbaldehyde derivatives of 2-hydroxybenzoic acid hydrazide

“…2A). We observed a similar association in other rhenium(I) halide complexes with hydrazone and thiosemicarbazone ligands [15,18,21]. These dimers are packed through weak C-HÁ Á ÁO carbonyl hydrogen bonds.…”

“…The mass spectra contain the signal corresponding to the molecular ion although the peaks due to the species [MÀX] + are more intense, as observed in the rhenium(I) complexes of benzoylhydrazones [9,15] and thiosemicarbazone derivatives [18]. A facial geometry around the rhenium atom is suggested by the three strong m(C"O) IR bands in the range 2027-1892 cm À1 in the complexes.…”

“…The ferrocenyl analog, H(Fc)L 1 in Scheme 1, was also prepared because of the potentially improved antitumor and antivirus activities of the ferrocenyl group [13,14] and the possibility of modulating the binding affinity of the ligand for the rhenium fragment by altering the redox state [15]. These studies show that the differences in the coordination of the ligand, j-N,N 0 in H(py)L 1 and j-N,O in H(Fc)L 1 , cause different spectroscopic behavior (mainly in 1 H NMR spectroscopy).…”

Tricarbonyl Rhenium(I) and Technetium(I) Complexes with Hydrazones Derived from 4,5‐Diazafluoren‐9‐one and 1,10‐Phenanthroline‐5,6‐dione

“…[25,32,34,43] The 1 H NMR spectra can readily be used to ensure the coordination mode of the hydrazone ligands in the rhenium complexes under study. In complexes in which the N-H group is part of the chelate ring by N,O ligand coordination, we have observed strong low-field shifts of these proton signals (about 2 ppm) [35,44] with respect to those for the free ligand. However, when the acyl group is not involved in the coordination, the signal is almost unmodified, even when it may be slightly shielded.…”

Copper(i) and nickel(ii) complexes with 1 : 1 vs. 1 : 2 coordination of ferrocenyl hydrazone ligands: Do the geometry and composition of complexes affect DNA binding/cleavage, protein binding, antioxidant and cytotoxic activities?

“…A broad shoulder found at 361 and 372 nm corresponds to ligand-to-metal (iron) charge transfer (LMCT) transitions and the band at 466 and 470 nm was assigned to charge transfer transition from iron to either a non-bonding or an antibonding orbital of the cyclopentadienyl ring. 51 Corresponding electronic spectrum of complexes 3-6 exhibited two or three bands in the range of 267 to 476 nm. Complex 3 exhibited three different absorptions positioned at 303, 343 and 384 nm whereas complex 4 showed only a couple of bands at 292 and 365 nm.…”