Synthesis, characterization and spectrochemical studies on a few binuclear µ-oxo molybdenum(V) complexes of pyrimidine derived Schiff base ligands

Abstract

Ten new binuclear singly oxo-bridged molybdenum complexes (complexes 1-10) were prepared using five pyrimidine derived Schiff base ligands and two Mo(V) precursors (NH 4 ) 2 MoOCl 5 and (NH 4 ) 2 MoOBr 5 . The ligands are prepared by the condensation of 4,6-dimethyl 2-hydrazino pyrimidine with salicylaldehyde (for HL 1 ), o-hydroxy acetophenone (for HL 2 ) and substituted salicylaldehydes (for HL 3 , HL 4 and HL 5 ) respectively. These ligands are already reported as good donors for Mo(VI) state. The μ-oxo Mo(V) complexes reported here bears a distorted octahedral geometry around each Mo atom with either N 2 O 2 Cl or N 2 O 2 Br chromophores. Fine variations in the spectroscopic behaviour of the complexes are observed in accordance with the varying electron donating properties of the ligands. All the complexes are unstable in solution and X-ray quality crystal of complex 1 could be isolated. All the complexes are characterized by IR and UV-Vis spectra.

Oxygen Atom Transfer Reactivity of Molybdenum(VI) Complexes Employing Pyrimidine- and Pyridine-2-thiolate Ligands

“…The low solubility prevented the recording of meaningful 1 H NMR data. This is on the one hand in accordance , yet on the other hand in contrast to the literature with reported NMR data for [Mo 2 O 3 (PyS) 4 ] ( 7 ) in acetone- d 6 as well as in chloroform- d . Interestingly, the latter gives data identical with our data for the dioxido compound [MoO 2 (PyS) 2 ] ( 2 ), which points toward residual 2 in the reported spectra presumably due to an incomplete reaction.…”

Synthesis, spectroscopic, DFT calculations, antimicrobial, cytotoxicity, and DNA binding studies of novel Cu (II), Ni (II), Zn (II), and VO (II) Schiff base complexes based on ibuprofen

“…nitrogen (-C=N), resulting in the formation of either enol-isomers or keto-isomers. [34] Furthermore, the v (C-O) vibration was displaced from 1242 cm À1 as observed in the ligand spectrum to the range 1243-1235 cm À1 in the complexes. [35] The ligand binds to all metal ions in a mono-negative bidentate fashion, according to these findings.…”

Synthesis, Characterization and Biological Evaluation of Transition and Inner Transition Metal Complexes of Ligands Derived Schiff Base from 1-phenyl-2, 3-dimethyl-4-(4-iminopentan-2-one)-pyrazole-5-one and 2-aminophenol

“…These bands are characteristic of octahedral geometry 26 . The Ru (III) complex demonstrates three band in its electronic spectrum at 13650 cm -1 , 17600 cm -1 and 22500 cm --1 , which may be assigned to 2 T 2g → 4 T 1g , 2 T 2g → 4 T 2g and 2 T 2g → 2 A 2g , 2 T 1g respectively for octahedral symmetry 27,28 . The V (III) complex shows a band at 16000 cm -1 with shoulder at 21000 cm -1 .…”