16483-18-4Relevant articles and documents
Fast Reactions at Planar Four-co-ordinate Complexes. Part 4. The Reaction of Chelate Dichloropalladium(II) Complexes with Some Bidentate Ligands
Cusumano, Matteo,Guglielmo, Giovanni,Ricevuto, Vittorio
, p. 1722 - 1725 (1981)
The reaction between the square-planar complexes and ethylenediamine proceeds in two consecutive stages yielding Cl2 as a final product.The intermediate species is Cl2 or when L-L is 1,2-bis(phenylthio)ethane.The rate of replacement of the first chloride co-ordinated to palladium(II) in the substrates at 25 deg C in dimethylformamide is strongly dependent on the nature of the ligand L-L, covering four orders of magnitude.The reaction between the substrates (M = Pd or Pt, bipy = 2,2'-bipyridine) and the bidentate nucleophiles ethylenediamine and dithio-oxamide proceeds according to an analogous two-stage reaction scheme when M is palladium; in the platinum derivatives, however, the chelate bipyridine is inert towards substitution.In the solvent dimethylformamide the entering group ethylenediamine behaves as a very effective nucleophile.
Effect of charge and surface area on the cytotoxicity of cationic metallointercalation reagents
Edwards, Gavin L.,Black, David St.C.,Deacon, Glen B.,Wakelin, Laurence P.G.
, p. 969 - 979 (2007/10/03)
Reaction of a series of nitrogen donor ligands (1-phenylpyrazoles, 2-phenylpyridine, benzo[h]quinoline, 1-(2′-pyridyl)indole, 1-phenylindazole, and 2-phenylindazole) with palladium(II) and platinum(II) salts gave complexes where ortho-metallation had occurred resulting in bidentate binding to the metal centres through N and C atoms. These cyclometallated products were isolated as μ-chloro dimers. Subsequent treatment of these μ-chloro dimers with chelating diamines such as 1,2-ethanediamine converted them into 14 cationic (1+) complexes. Analogous coordination mixed ligand complexes (charge 2+) were prepared by reaction of dichloro(1,2-ethanediamine-N, N′)palladium(II) with aromatic diamines such as 2-(1′-pyrazolyl) pyridine, 2,2′-bipyridine, and 1,10-phenanthroline. The complexes exhibited growth inhibitory activity against L1210 mouse leukaemia cells in vitro over a wide concentration range; in general, the cyclometallated complexes were more active than the mixed ligand complexes, although one cyclometallated organoplatinum complex was less active than the mixed ligand analogue. Substitution around the periphery of the aromatic ligands also resulted in increased activity. One complex, derived from 1-(2′-pyridyl) indole, was tested in vivo and showed no significant antitumour inhibition against P388 leukaemia at doses below toxic levels.
Fast Reactions at Planar Four-co-ordinate Complexes. Part 5. The Solvent Effect on the Leaving Group in the Reactions of Neutral and Cationic Palladium(II) Complexes
Cusumano, Matteo,Giannetto, Antonio,Guglielmo,Giovanni,Ricevuto, Vittorio
, p. 2445 - 2448 (2007/10/02)
The rate of replacement of the group X by n-propylamine or thiourea in the substrates NO3 (3-NHpd = 3-azapentane-1,5-diamine; X=Cl, Br, I, N3, SCN, or NO2) and the equilibrium constants of some of these reactions have been studied in the solvents methanol, dimethylformamide, and dimethylsulfoxide at 25 deg C.The kinetics of substitution of the first group X, by ethylenediamine, in the substrates in dimethylformamide and in some cases in methanol, at 25 deg C, have also been followed.Both rate and equilibrium constants vary sensibly on going from protic to dipolar aprotic solvents.The lability sequence of the leaving group depends on the nature of the substrates and in all cases is affected to a large extent by the change in the solvent nature.
