The reaction between [NnBu4][(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(I)2] (C^N = κ2-N,C-benzoquinolinate, 1) and (i) bidentate S^S, N^S and O^O anionic ligands or (ii) monodentate S- N- or O-based anionic ligands was studied in order to investigate the factors that may guarantee the stability of Pt(ii),Pt(iv) mixed-valence dinuclear phosphanido complexes. While reactions of 1 with S^S or N^S ligands afforded stable Pt(ii),Pt(iv) species of general formula [(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(L^S)]x- [(L^S)(x-1) = 2-mercaptopyrimidinate (pymS-), 2-mercaptopyridinate (pyS-), dimethyldithiocarbamate (Me2NCS2-), ethyl xanthogenate (EtOCS2-) and 1,2-benzenedithiolate (PhS22-)], the reaction of 1 with the O^O ligand sodium acetylacetonate gave several products, and no pure Pt(ii),Pt(iv) complex could be isolated. The reaction of monodentate ligands such as PhS-, OH- or N3- with 1 led to a stable Pt(ii),Pt(iv) complex only in the case of N3-. The reaction with OH- afforded the Pt(ii),Pt(ii) complex [(C6F5)2PtII(μ-PPh2)(κ2-O,P-μ-O-PPh2)PtII(C^N)]- (8) deriving from reductive coupling of a diphenylphosphanide and an O-donor ligand coordinated to the Pt(iv) centre, while the reaction with PhS- produced the unstable Pt(ii),Pt(iv) complex [NnBu4][(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(PhS)2] (11) that evolved in solution to the Pt(ii),Pt(ii) species [NnBu4][(C6F5)2PtII(μ-PPh2)2PtII(C^N)] (9) by elimination of diphenyldisulfide. Thus, the stability of mixed valence Pt(ii),Pt(iv) phosphanide complexes is affected by several concurrent factors, including the chelating effect of the ligands and the type of ligating atoms.
Stable mixed-valence diphenylphosphanido bridged platinum(ii)-platinum(iv) complexes / Fortuño, Consuelo; Martín, Antonio; Mastrorilli, Piero; Latronico, Mario; Petrelli, Valentina; Todisco, Stefano. - In: DALTON TRANSACTIONS. - ISSN 1477-9226. - STAMPA. - 49:15(2020), pp. 4935-4955. [10.1039/d0dt00712a]
Stable mixed-valence diphenylphosphanido bridged platinum(ii)-platinum(iv) complexes
Piero Mastrorilli;Mario Latronico;Valentina Petrelli;Stefano Todisco
2020-01-01
Abstract
The reaction between [NnBu4][(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(I)2] (C^N = κ2-N,C-benzoquinolinate, 1) and (i) bidentate S^S, N^S and O^O anionic ligands or (ii) monodentate S- N- or O-based anionic ligands was studied in order to investigate the factors that may guarantee the stability of Pt(ii),Pt(iv) mixed-valence dinuclear phosphanido complexes. While reactions of 1 with S^S or N^S ligands afforded stable Pt(ii),Pt(iv) species of general formula [(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(L^S)]x- [(L^S)(x-1) = 2-mercaptopyrimidinate (pymS-), 2-mercaptopyridinate (pyS-), dimethyldithiocarbamate (Me2NCS2-), ethyl xanthogenate (EtOCS2-) and 1,2-benzenedithiolate (PhS22-)], the reaction of 1 with the O^O ligand sodium acetylacetonate gave several products, and no pure Pt(ii),Pt(iv) complex could be isolated. The reaction of monodentate ligands such as PhS-, OH- or N3- with 1 led to a stable Pt(ii),Pt(iv) complex only in the case of N3-. The reaction with OH- afforded the Pt(ii),Pt(ii) complex [(C6F5)2PtII(μ-PPh2)(κ2-O,P-μ-O-PPh2)PtII(C^N)]- (8) deriving from reductive coupling of a diphenylphosphanide and an O-donor ligand coordinated to the Pt(iv) centre, while the reaction with PhS- produced the unstable Pt(ii),Pt(iv) complex [NnBu4][(C6F5)2PtII(μ-PPh2)2PtIV(C^N)(PhS)2] (11) that evolved in solution to the Pt(ii),Pt(ii) species [NnBu4][(C6F5)2PtII(μ-PPh2)2PtII(C^N)] (9) by elimination of diphenyldisulfide. Thus, the stability of mixed valence Pt(ii),Pt(iv) phosphanide complexes is affected by several concurrent factors, including the chelating effect of the ligands and the type of ligating atoms.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.