Reaction of the trinuclear [NBu4]2[(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(RF)2] (1, RF = C6F5) with HCl results in the formation of the unusual anionic hexanuclear derivative [NBu4]2[{(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(μ-Cl)}2] (4, 96 e- skeleton) through the cleavage of two Pt-C6F5 bonds. The reaction of 4 with Tl(acac) yields the trinuclear [NBu4][(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(acac)] (5, 48 e- skeleton), which is oxidized by Ag+ to form the trinuclear compound [(RF) 2Pt(μ-PPh2)2Pt(μ-PPh2) 2Pt(acac)][ClO4] (6, 46 e- skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II), which displays a Pt-Pt bond. The reduction of 6 by [NBu4][BH4] gives back 5. The treatment of 6 with Br- (1:1 molar ratio) at room temperature gives a mixture of the isomers [(PPh2RF)(RF)Pt(μ-PPh 2)(μ-Br)Pt(μ-PPh2)2Pt(acac)], having Br trans to RF (7a) or Br cis to RF (7b), which are the result of PPh2/C6F5 reductive coupling. The treatment of 5 with I2 (1:1 molar ratio) yields the hexanuclear [{(PPh2RF)(RF)Pt(μ-PPh2)(μ-I) Pt(μ-PPh2)2Pt(μ-I)}2] (8.96 e- skeleton), which is easily transformed into the trinuclear compound [(PPh 2RF)(RF)Pt(μ-PPh2)(μ-I) Pt(μ-PPh2)2Pt(I)(PPh3)] (9, 48 e- skeleton). Reaction of [(RF)2Pt(μ-PPh 2)2Pt(μ-PPh2)2Pt(NCMe) 2] (10) with I2 at 213 K for short reaction times gives the trinuclear platinum derivative [(RF)2Pt(μ-PPh 2)2Pt(μ-PPh2)2Pt(I)2] (11, 46e skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II) and with a Pt-Pt bond, while the reaction at room temperature and longer reactions times gives 8. The structures of the complexes have been established by multinuclear NMR spectroscopy. In particular, the 195Pt NMR analysis, carried out also by 19F-195Pt heteronuclear multiple-quantum coherence, revealed an unprecedented shielding of the 195Pt nuclei upon passing from Pt(II) to Pt(III). The X-ray diffraction structures of complexes 4, 5, 6, 9, and 11 have been studied. A detailed study of the relationship between the complexes has been carried out
Unsymmetrical Platinum(II) Phosphido Derivatives: Oxidation and Reductive Coupling Processes Involving Platinum(III) Complexes as Intermediates / Ara, I; Fornies, J; Fortuno, C.; Ibanez, S.; Martin, A.; Mastrorilli, Pietro; Gallo, Vito. - In: INORGANIC CHEMISTRY. - ISSN 0020-1669. - 47:19(2008), pp. 9069-9080. [10.1021/ic8011124]
Unsymmetrical Platinum(II) Phosphido Derivatives: Oxidation and Reductive Coupling Processes Involving Platinum(III) Complexes as Intermediates
MASTRORILLI, Pietro;GALLO, Vito
2008-01-01
Abstract
Reaction of the trinuclear [NBu4]2[(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(RF)2] (1, RF = C6F5) with HCl results in the formation of the unusual anionic hexanuclear derivative [NBu4]2[{(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(μ-Cl)}2] (4, 96 e- skeleton) through the cleavage of two Pt-C6F5 bonds. The reaction of 4 with Tl(acac) yields the trinuclear [NBu4][(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(acac)] (5, 48 e- skeleton), which is oxidized by Ag+ to form the trinuclear compound [(RF) 2Pt(μ-PPh2)2Pt(μ-PPh2) 2Pt(acac)][ClO4] (6, 46 e- skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II), which displays a Pt-Pt bond. The reduction of 6 by [NBu4][BH4] gives back 5. The treatment of 6 with Br- (1:1 molar ratio) at room temperature gives a mixture of the isomers [(PPh2RF)(RF)Pt(μ-PPh 2)(μ-Br)Pt(μ-PPh2)2Pt(acac)], having Br trans to RF (7a) or Br cis to RF (7b), which are the result of PPh2/C6F5 reductive coupling. The treatment of 5 with I2 (1:1 molar ratio) yields the hexanuclear [{(PPh2RF)(RF)Pt(μ-PPh2)(μ-I) Pt(μ-PPh2)2Pt(μ-I)}2] (8.96 e- skeleton), which is easily transformed into the trinuclear compound [(PPh 2RF)(RF)Pt(μ-PPh2)(μ-I) Pt(μ-PPh2)2Pt(I)(PPh3)] (9, 48 e- skeleton). Reaction of [(RF)2Pt(μ-PPh 2)2Pt(μ-PPh2)2Pt(NCMe) 2] (10) with I2 at 213 K for short reaction times gives the trinuclear platinum derivative [(RF)2Pt(μ-PPh 2)2Pt(μ-PPh2)2Pt(I)2] (11, 46e skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II) and with a Pt-Pt bond, while the reaction at room temperature and longer reactions times gives 8. The structures of the complexes have been established by multinuclear NMR spectroscopy. In particular, the 195Pt NMR analysis, carried out also by 19F-195Pt heteronuclear multiple-quantum coherence, revealed an unprecedented shielding of the 195Pt nuclei upon passing from Pt(II) to Pt(III). The X-ray diffraction structures of complexes 4, 5, 6, 9, and 11 have been studied. A detailed study of the relationship between the complexes has been carried outI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
