92763-59-2Relevant academic research and scientific papers
Control of aminophosphine chelate ring-opening in Pt(II) and Pd(II) complexes: Potential dual-mode anticancer agents
Habtemanam, Abraha,Watchman, Beth,Potter, Brian S.,Palmer, Rex,Parsons, Simon,Parkin, Andrew,Sadler, Peter J.
, p. 1306 - 1318 (2007/10/03)
We show that bis(aminophosphine) complexes of the type [M(R1R2N(CH2)nPPh2)2 ]2+, M = Pt(II) or Pd(II), can exist in chelate ring-closed and ring-opened forms both in the solid state and in aqueous solution. The equilibrium between them in solution can be controlled by the nature of the groups R1 and R2 (H, Me, Bz, cyclohexyl), by the bridge length n, and by the pH and Cl- concentration. X-Ray crystal structures are reported for the ring-closed complexes cis-[Pt(H2N(CH2)2PPh2-P,N)2 ]Cl2, cis-[Pt(H2N(CH2)3PPh2-P,N)2 ]Cl2, and cis-[Pt(Me(H)N(CH2)2PPh2-P,N)2][HCl 2]2, the mono-ring-opened complex cis-[Pd(Me2N(CH2)2PPh2-N,P)Cl(Me 2NH(CH2)2PPh2-P)](NO3) 2, the di-ring-opened complex cis-[Pt(Me2N(CH2)3PPh2-P)2 CL2], and, for comparison, the monochelate cis-[Pd(Me2N(CH2)3PPh2-N,P)CL2 ]. These square-planar complexes exhibit varying degrees of distortion and variable M-N bond lengths dependent not only on the trans influence of P but also on steric effects within the complex, pH-induced chelate ring-opening of cis-[Pt(Me2N(CH2)2PPh2-P,N)2 ]CL2 had an associated pK value of 6.9. In contrast, complexes with R1 and R2 = H, n = 2 or 3 or R1 = H and R2 = Me, n = 2, are more difficult to ring-open. Thus the complexes cis-[Pt(Me(H)N(CH2)2-PPh2-P,N)2]CL 2 and cis-[Pt(H2N(CH2)3PPh2-P,N)2 ]CL2, had associated pK values of 2.1 and 2.9, respectively. These aminophosphine complexes may exhibit anticancer activity by two mechanisms: by disrupting mitochondrial membrane potentials as bis-chelated (ring-closed) lipophilic cations, or by direct binding to DNA bases as ring-opened complexes.
Platinum (II) complexes of unsymmetrical, potentially bidentate ligands
Anderson, Gordon K.,Kumar, Ravi
, p. 4064 - 4068 (2008/10/08)
The reactions of a series of unsymmetrical, potentially bidentate ligands Ph2P(CH2)nX (n = 2, X = OMe, NMe2, SMe; n = 3, X = NMe2) with [PtX2(cod)] (X = Cl, I) are described. The tendency of the ligand to bond to the metal in a bidentate fashion is dependent on the nature of the weak donor, and on the size of the chelate ring formed. Halide abstraction by Ag+ promotes coordination of the ether function to yield [PtCl(Ph2PCH2CH2OMe)2]+ and [Pt(Ph2PCH2CH2OMe)2]2+. Reactions of the former with a number of weak donor ligands have been studied by 31P{1H} NMR spectroscopy. Complex mixtures are obtained with Ph2PCH2CH2SMe, and the involvement of ion-paired species is suggested in this case.
