Synthesis and characterization of two new niobium(V) diperoxo complexes containing 8-quinolinolate as the ligand

Synthesis, spectroscopic study and anticancer activity of a water-soluble Nb(V) peroxo complex

“…As far as the metal peroxo stretching vibrations are concerned, two bands are observed near 613 cm − 1 and 550 cm − 1 corresponding to the symmetric and asymmetric ν[Nb(O 2 )] vibrations respectively. The vibrations above are in accordance with the characteristic spectral features reported in the literature for a peroxo-metal compound, with a peroxide group coordinated to the Nb metal center in a η 2 mode [36,41,45,46]. Additional band of medium intensity at 450 cm − 1 absent in the AscA spectrum, most likely represent the Nb-O stretching frequency bonds.…”

“…The reaction of the AscA with oxygen is slow in the acidic solution giving O 2 2− and dehydroascorbic acid [39]. In the presence of Nb(V) the rate of the O 2 2− production is enhanced and the peroxo complex is formed [37,40,41]. 3)).…”

Synthesis, single crystal structure determination, and solution behavior of an 8-hydroxyquinoline derivative of niobium(V) ethoxide

“…Furthermore, there is considerable shielding of the proton attached to carbon atom adjacent to the oxygen (phenolic ring) in comparison to the free ligand. Such a shift has been observed for the other niobium(V) complexes containing 8-quinolinoate as the ligand [22].…”

Spectroscopic and Structural Characterizations of Novel Water‐Soluble Peroxo[polyaminocarboxylato bis(N‐oxido)]niobate(V) Complexes

“…Several such complexes have already been described in the literature; they correspond either to homoleptic tetraperoxoniobates of general formula (A I ) 3 [9,11] and K[Nb(O 2 ) 2 (L) 2 ]·3H 2 O (L ϭ 8-hydroxyquinolinate). [12] As far as the peroxo(polyaminocarboxylato) compounds are concerned, only a few studies have been reported and they are essentially restricted to the edta(peroxo) compound [a] and its solution chemistry. [13,14] A bis(aqua)edta complex of Nb IV , [Nb(edta)(H 2 O) 2 ]·2H 2 O, has also been described.…”