Ligand-Mediated C-Br Oxidative Addition to Cycloplatinated(II) Complexes and Benzyl-Me C-C Bond Reductive Elimination from a Cycloplatinated(IV) Complex.

Reaction of the Pt(II) complexes [PtMe(pbt)], , (pbt = 2-(2-pyridyl)benzothiazole) and [PtMe(C^N)(PPhMe)] [C^N = deprotonated 2-phenylpyridine (ppy), , or deprotonated benzo[h]quinoline (bhq), ] with benzyl bromide, PhCHBr, is studied. The reaction of with PhCHBr gave the Pt(IV) product complex [PtBr(CHPh)Me(pbt)]. The major trans isomer is formed in a trans oxidative addition (), while the minor cis products ( and ) resulted from an isomerization process.

Chelating and Bridging Roles of 2-(2-Pyridyl)benzimidazole and Bis(diphenylphosphino)acetylene in Stabilizing a Cyclic Tetranuclear Platinum(II) Complex.

The reaction of complex [Pt(Me)(DMSO)(pbz)], , (pbz = 2-(2-pyridyl)benzimidazolate) with [PtMe(Cl)(DMSO)], , followed by addition of bis(diphenylphosphino)acetylene (dppac), gave the novel tetranuclear platinum complex [PtMe(μ-dppac)(pbz)Cl], , bearing both the pbz and dppac ligands. In this structure, the pbz ligands are both chelating and bridging to stabilize the tetraplatinum framework. The tetranuclear Pt(II) complex was fully characterized by NMR spectroscopy, X-ray crystallography, and mass spectrometry, and its electronic structure was investigated and supported by DFT calculations.

Effects of the number of cyclometalated rings and ancillary ligands on the rate of MeI oxidative addition to platinum(ii)-pincer complexes.

Organoplatinum(ii)-pincer complexes [Pt(C^N^C)(L)] (2a; L = PPhMe, 2b; L = pyridine (py), 2c; L = 4-picoline (pic)) are synthesized by the reaction of [Pt(C^N^C)(DMSO)], 1, with 1 equiv. of L, where HC^N^CH = 2,6-diphenylpyridine. Complexes 2 have 5d(Pt) →π*(pincer) metal-to-ligand charge-transfer bands in the visible region, which were used to easily follow the kinetics of their reactions with MeI by using UV-vis spectroscopy.

Anticancer and DNA binding activities of platinum (IV) complexes; importance of leaving group departure rate.

The two six-coordinate Pt(IV) complexes, containing bidentate nitrogen donor/methyl ligands with general formula [Pt(X)2Me2((t)bu2bpy)], where (t)bu2bpy = 4,4'-ditert-butyl-2,2'-bipyridine and X = Cl (C1) or Br (C2), serving as the leaving groups were synthesized for evaluation of their anticancer activities and DNA binding properties. To examine anticancer activities of the synthetic complexes, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ethidium bromide/acridine orange (EB/AO) staining method were performed. The binding properties of these complexes to DNA and purine nucleotides were examined, using different spectroscopic techniques.