Comparative Ligand Field Studies. IV. Vanadium(IV), Titanium(III), Molybdenum(V), and other Systems with one d-Electron.

Synthesis and insulinomimetic activities of novel mono- and tetranuclear oxovanadium(IV) complexes with 3-hydroxypyridine-2-carboxylic acid

“…e à p , and the other is a b 2 ! b à 1 transition [16,17]. These values are quite close to those of VO(pic) 2 (732 nm (40.8 M À1 cm À1 ) and 542 nm (19.6 M À1 cm À1 )) [9].…”

Electronic Structures of Oxo-Metal Ions

“…Jørgensen first used crystal field (CF) theory to explain the absorption spectrum of the aqueous vanadyl ion, its complexes with donor ligands (edta, oxalate, acetylacetonate, and tartrate), as well as that of molybdenyl chloride (MoOCl 5 2À ) [8]. Importantly, the spectra of the edta and tartrate complexes exhibit a third weak band maximizing in the 25,000-30,000 cm À1 range (e < 50 M À1 cm À1 ion [8].…”

“…Measurements reported a year later on complexes of the vanadyl ion with thiocyanate revealed that the asymmetry is due to a second absorption feature: a shoulder at~650 nm in vanadyl sulfate; a resolved 560 nm maximum in the SCN À complex [7]. Jørgensen first used crystal field (CF) theory to explain the absorption spectrum of the aqueous vanadyl ion, its complexes with donor ligands (edta, oxalate, acetylacetonate, and tartrate), as well as that of molybdenyl chloride (MoOCl 5 2À ) [8]. Importantly, the spectra of the edta and tartrate complexes exhibit a third weak band maximizing in the 25,000-30,000 cm À1 range (e < 50 M À1 cm À1 ion [8].…”

“…Electronic Structures of Oxo-Metal Ionsanalysis of the vanadyl spectrum [8]. Taube attributed the formation of -yl ions to the fact that the Lewis acidic metal center exerts a selective polarization of the surrounding water molecules, leading to double deprotonation of one water ligand rather than single deprotonation of two waters [16].…”

Sb (III) complexes derived from 5-phenyl-1H-imidazole-4- carbaldehyde and O or S containing dihydrazide with their antibacterial and spectroscopic studies

“…Schiff base metal complexes have been known since the mid nineteenth century [12] and even before the general preparation of the Schiff bases ligands themselves. Schiff base metal complexes have occupied a central place in the development of coordination chemistry after the work of Jorgensen and Werner [13].…”