- A vibrational study of the metal-olefin bond in norbornadiene complexes of Rh(I), Pd(II) and Pt(II)
-
Vibrational assignments of the complexes 2, PtCl2C7H8, and PdCl2C7H8 have been undertaken.A reinvestigation of the norbornadiene spectrum was necessary and a new set of assignments is given.The shift in energy of bands I and II and the out-of-plane olefinic C-H wagging modes, as well as the relative energies of the bands associated with the metal-olefin motions are consistent with the total metal-norbornadiene interaction following the order Rh > Pt > Pd and the excent of the ? component being ordered as Rh ca/= Pt > Pd.
- Wertz, D. W.,Moseley, M. A.
-
-
Read Online
- Dichloro(norbornadiene)platinum(II): A comparison with dichloro(cyclooctadiene)platinum(II)
-
The crystal structure of the title compound, (bicyclo[2.2.1]-hepta-2,5- diene)dichloroplatinum(II), [PtCl2(C7H8)], has been determined from single-crystal X-ray analysis. The coordination sphere about the Pt atom is pseudo-square planar, with shorter Pt - C distances than in the corresponding dichloro(cyclooctadiene)platinum(II) complex.
- Butikofer, Jeffrey L.,Kalberer, Eric W.,Schuster, William C.,Roddick, Dean M.
-
-
Read Online
- Synthesis and reactivity of [(C2F5)2MeP]2Pt(Me)X (X = Me, O2CCF3, OTf, OSO2F): A reactivity comparison with chelate acceptor analogues
-
A comparative study of new platinum methyl complexes cis-(dfmp)2Pt(Me)2 and trans-(dfmp)2Pt(Me)X (dfmp = (C2F5)2MeP; X = O2CCF3, OTf, OSO2F) with previously reported acceptor chelate analogues (dfepe)Pt(Me)X (dfepe = (C2F5)2PCH2CH2P (C2F5)2; X = Me, O2CCF3, OTf, OSO2F) is presented. In contrast to (dfepe)Pt(Me)2, which is inert to both H2 and CO addition, cis-(dfmp)2Pt(Me)2 reacts readily to form (dfmp)4Pt and cis-(dfmp)(CO)-Pt(Me)2, respectively. Similarly, whereas (dfepe)Pt(Me)2 is stable up to 180°C, thermolysis of cis-(dfmp)2Pt(Me)2 in benzene-d6 at 80°C leads to ethane reductive elimination and production of (dfmp)4Pt. Dissolving cis-(dfmp)2Pt(Me)2 in neat trifluoroacetic, triflic, or fluorosulfonic acid at ambient temperature cleanly produces the corresponding trans-(dfmp)2Pt(Me)(X) complexes. Attempted isolation of trans-(dfmp)2Pt(Me)(O2CCF3) resulted in dfmp loss and reversible formation of the crystallographically characterized dimer, [(dfmp)Pt(Me)(μ-O2CCF3)]2. Monitoring the thermolysis of trans-(dfmp)2Pt(Me)(X) complexes by 31P NMR in their respective neat acids reveals a kinetic protolytic stability that is dependent on the nature of the trans X ligand: whereas trans-(dfmp)2Pt(Me)(O2CCF3) is less stable than the corresponding (dfepe)Pt(Me)(O2CCF3) complex, trans-(dfmp)2Pt(Me)-(OTf) and trans-(dfmp)2Pt(Me)(OSO2F) are significantly more resistant to protolytic cleavage than the chelating analogues. Thermolysis in CF3CO2D or DOTf resulted in deuteration of the methyl ligand prior to methane loss, indicating the reversible formation of a methane adduct intermediate.
- Butikofer, Jeffrey L.,Hoerter, Justin M.,Peters, R. Gregory,Roddick, Dean M.
-
-
Read Online
- Platinum diolefin complexes - Synthesis, structures, and cytotoxicity
-
The synthesis, spectroscopy, structures and chemical reactivity of platinum(II) diolefin complexes cis-[(||∧||)PtCl2], cis-[(||∧||)PtCl(R)] and cis-[(||∧||)Pt(R)2] [||∧|| = chelate diolefin ligand: 1,5-cyclooctadiene (COD), 1,5-dimethylocta-1,5-diene (Me2COD), norbornadiene (NBD), 1,5-hexadiene (HEX), 3-allyloxypropene (All2O, diallyl ether), diallylamine (All2NH); R = Me, Bn, C6F5, C6F4H-4 (or -5), or C≡C(4-Me)Ph] have been explored. The relative exchange rates of the cis-[(||∧||)-PtCl2] complexes towards the diimine ligand diisopropyl-1,4-diazabutadiene (iPr-DAB) increased along the series COD 2COD 2O by a factor of 4. The presumably dimeric complex [(All2NH)PtCl2]2 undergoes a unique rearrangement process in dimethyl sulfoxide (DMSO) solution to yield the dimeric piperazine complex [PtCl(dmso)-(C6H10N)]2, which has been characterised by single-crystal XRD. For selected platinum complexes, cytotoxic effects in HT-29 colon carcinoma and MCF-7 breast cancer cell lines were evaluated. For comparison, the dicationic complexes [(COD)Pt(Bn)(L)][PF6]2 with the very labile coligands N-methyl-4,4′-bipyridinium (MQ+) and N-methyl-1,4-pyrazinium (Mpz+) were added to the study. Although the hexadiene complexes [(HEX)Pt(C6F4H-4)2] and [(HEX)Pt(C6F4H-5)2] show strong cytotoxicity, the introduction of labile diolefin ligands or the labile cationic MQ+ or Mpz+ coligands does not generally lead to markedly increased cytotoxicity.
- Lüning, Anna,Neugebauer, Michael,Lingen, Verena,Krest, Alexander,Stirnat, Kathrin,Deacon, Glen B.,Drago, Penny R.,Ott, Ingo,Schur, Julia,Pantenburg, Ingo,Meyer, Gerd,Klein, Axel
-
-
Read Online
- Convenient preparation of (η4-alkadiene)dichloroplatinum(II) complexes from [PtCl6]2- anions and their reduction to platinum(0) alkene complexes under phase-transfer catalysis conditions
-
Convenient one-pot reduction-complexation reactions of hexachloroplatinato(IV) anions to (η4-alkadiene) dichloroplatinum(II) complexes (η4-alkadiene = COD, DAE, DCPD, NBD) under suitable phase-transfer catalysis conditions are reported. Reduction to zerovalent platinum alkene complexes has been obtained in the presence of an excess of alkene, potassium formate and 18-crown-6 as phase-transfer catalyst (alkene = COD, NB, dba). The crystal and molecular structure of [Pt 1.03(dba)3]·CH2Cl2 has been studied by X-ray diffraction methods: it can be described as a solid solution of Pt(dba)3 and Pt2(dba)3, the mononuclear complex being largely prevailing.
- Dell'Amico, Daniela Belli,Labella, Luca,Marchetti, Fabio,Samaritani, Simona
-
p. 1349 - 1354
(2011/05/09)
-
- Competition between carbon monoxide and alkenes in chloro complexes of platinum(II)
-
Alkenes (cyclohexene; 1-octene) and dienes (cyclooctadiene, COD; norbornadiene, NBD) react with cis-PtCl2(CO)2, leading, respectively, to partial and complete displacement of coordinated carbon monoxide. Equilibrium constants at 21 °
- Dell'Amico, Daniela Belli,Bini, Riccardo,Calderazzo, Fausto,Carbonaro, Laura,Labella, Luca,Vitullo, Anna
-
p. 4427 - 4431
(2008/10/09)
-