Synthesis, structure, and spectroscopic properties of acetato(dimethyl)(pyridine-2-carbaldehydethiosemicarbazonato)tin(IV) acetic acid solvate, [SnMe2(PyTSC)(OAc)].HOAc. Comparison of its biological activity with that of some structurally related diorganotin(IV) bis(thiosemicarbazonates)

Antibacterial, antifungal and in vitro antileukaemia activity of metal complexes with thiosemicarbazones

1-phenyl-3-methyl-4-benzoyl-5-pyrazolone 4-ethyl-thiosemicarbazone (HL) and its copper(II), vanadium(V) and nickel(II) complexes: [Cu(L)(Cl)]·C₂H₅OH·(1), [Cu(L)₂]·H₂O (2), [Cu(L)(Br)]·H₂O·CH₃OH (3), [Cu(L)(NO₃)]·2C₂H₅OH (4), [VO₂(L)]·2H₂O (5), [Ni(L)₂]·H₂O (6), were synthesized and characterized. The ligand has been characterized by elemental analyses, IR, ¹H NMR and ¹³C NMR spectroscopy. The tridentate nature of the ligand is evident from the IR spectra. The copper(II), vanadium(V) and nickel(II) complexes have been characterized by different physico-chemical techniques such as molar conductivity, magnetic susceptibility measurements and electronic, infrared and electron paramagnetic resonance spectral studies. The structures of the ligand and its copper(II) (2, 4), and vanadium(V) (5) complexes have been determined by single-crystal X-ray diffraction. The composition of the coordination polyhedron of the central atom in 2, 4 and 5 is different. The tetrahedral coordination geometry of Cu was found in complex 2 while in complex 4, it is square planar, in complex 5 the coordination polyhedron of the central ion is distorted square pyramid. The in vitro antibacterial activity of the complexes against Escherichia coli, Salmonella abony, Staphylococcus aureus, Bacillus cereus and the antifungal activity against Candida albicans strains was higher for the metal complexes than for free ligand. The effect of the free ligand and its metal complexes on the proliferation of HL-60 cells was tested.

Synthesis, structure, spectroscopic properties and biological activity of mixed diorganotin(IV) complexes containing pyridine-2-carbaldehyde thiosemicarbazonato and diphenyldithiophosphinato ligands

Reaction of the title ligands (HPyTSC and HS(S)PPh2, respectively) with R2SnO (R = Me, Et, Bu) in ethanol (EtOH) afforded the complexes [SnMe2(PyTSC) (S2PPh2)].EtOH (1) and [SnR2(PyTSC) (S2PPh2)] (R = Et (2), Bu (3)). The structures of 1 and 2 were determined by single-crystal X-ray diffractometry. In both these complexes the tin atom is coordinated to an N,N,S-dentate thiosemicarbazonate ligand, an anisobidentate dithiophosphinato ligand and the two R groups. The coordination polyhedrons can be described as distorted pentagonal bipyramids. A comparative study of the IR spectra of 1, 2 and 3 indicates that the butyl complex has a similar structure. Multinuclear (1H, 13C, 31P and 119Sn) NMR data suggest that the structures of 1 and 2 probably remain in CDCl3 (or DMSO-d6) solution but compound 3 partially decomposes in these media. Preliminary results on the effects of the complexes on the proliferation and differentiation of FLC, CEM, U937, K562 and TOM-1 leukaemia cells, and on the clonogenic activity of K562 cells are also described.