Synthesis and reactivity of the unsaturated trinuclear phosphanido complex [(C6F5)2Pt(μ-PPh2)2Pt(μ-PPh2)2Pt(PPh3)].
The reaction of [NBu(4)][(C(6)F(5))(2)Pt(μ-PPh(2))(2)Pt(μ-PPh(2))(2)Pt(O,O-acac)] (48 VEC) with [HPPh(3)][ClO(4)] gives the 46 VEC unsaturated [(C(6)F(5))(2)Pt(1)(μ-PPh(2))(2)Pt(2)(μ-PPh(2))(2)Pt(3)(PPh(3))](Pt(2)-Pt(3)) (1), a trinuclear compound endowed with a Pt-Pt bond. This compound displays amphiphilic behavior and reacts easily with nucleophiles L, yielding the saturated complexes [(C(6)F(5))(2)Pt(II)(μ-PPh(2))(2)Pt(II)(μ-PPh(2))(2)Pt(II)(PPh(3))L] [L = PPh(3) (2), py (3)]. The reaction with the electrophile [Ag(OClO(3))PPh(3)] affords the adduct 1·AgPPh(3), which evolves, even at low temperature, to a mixture in which [(C(6)F(5))(2)Pt(III)(μ-PPh(2))(2)Pt(III)(μ-PPh(2))(2)Pt(II)(PPh(3))(2)](2+)(Pt(III)-Pt(III)) and 2 (plus silver metal) are present. The nucleophilic nature of 1 is also demonstrated through its reaction with cis-[Pt(C(6)F(5))(2)(THF)(2)], which results in the formation of [Pt(4)(μ-PPh(2))(4)(C(6)F(5))(4)(PPh(3))] (4). The structure and NMR features indicate that 1 can be better considered as a Pt(II)-Pt(III)-Pt(I) complex instead of a Pt(II)-Pt(II)-Pt(II) derivative. Theoretical calculations (density functional theory) on similar model compounds are in agreement with the assigned oxidation states of the metal centers. The strong intermetallic interactions resulting in a Pt(2)-Pt(3) metal-metal bond and the respective bonding mechanism were verified by employing a multitude of computational techniques (natural bond order analysis, the Laplacian of the electron density, and localized orbital locator profiles).
Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea, Universidad de Zaragoza, CSIC, 50009 Zaragoza, Spain.
Juan
J
Forniés
Consuelo
C
Fortuño
Susana
S
Ibáñez
Antonio
A
Martín
Piero
P
Mastrorilli
Vito
V
Gallo
Athanassios
A
Tsipis
D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D009944:Organoplatinum Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D011789:Quantum Theory
D009943:Organophosphorus Compounds; D009944:Organoplatinum Compounds