A linear triplatinum tetrahydride complex featuring two Pt–Pt bonds

Abstract

The synthesis and characterisation of the linear triplatinum complex [(H)(PHBu(t)2)Pt(mu-H)(mu-PBu(t)2)Pt(micro-PBu(t)2)(mu-H)Pt(PHBu(t)2)(H)] featuring two Pt-Pt bonds is reported.

Behavior of Neutral Phosphido Derivatives of Platinum and Palladium toward Silver Centers

“…The 31 P{ 1 H} NMR spectrum of 11 shows four signals (see Scheme for the atom numbering) and indicates that the structure proposed in the solid state is maintained in solution. The two signals due to the P atoms of the phosphido ligands appear at low fields, in agreement with the presence of the bridging phosphides subtending a Pd–Pt bond. ,− The presence of the Pt–Pd bond is also supported by the value of the coupling between Pt and P 3 atoms, 92 Hz. − Moreover, the chemical shift of the P 2 atom (phosphido group bridging two metal centers, μ 2 -PPh 2 ) appears at δ 293.2, while the P 1 atom (phosphido group bridging three metal centers, μ 3 -PPh 2 ) appears at δ 138.3. This decrease in the value of δ on going from a μ 2 -PPh 2 coordination mode to a μ 3 -PPh 2 one has been observed before, ,,− and in complex 11 , this Δδ (155 ppm) is greater than in the previously reported complexes [MM′Pt(μ-PPh 2 ) 2 (R F ) 2 (PPh 3 ) 2 ][ClO 4 ] (M = Pt, Pd; M′ = Ag, Au) .…”

Bridging and Terminal (Phosphanido)platinum Complexes

“…Compounds [(C 6 F 5 ) 2 Pt(μ‐PPh 2 ) 2 Pt(μ‐X) 2 Pt(PPh 3 ) 2 ] ( 119 ),95 [(H)(PEt 3 )Pt(μ‐PPh 2 ) 2 Pt(μ‐PPh 2 ) 2 Pt(H)(PEt 3 )] ( 120 ),48 [Pt 3 X 4 {(+) δ ‐L} 2 ] {X = Cl, Br; L = deprotonated form of P,P,P′ ‐tris[(+)‐9‐phenyldeltacyclan‐8‐yl]‐1,2‐bis(phosphanyl)‐benzene} ( 121 )72 and [(C 6 F 5 )(PPh 3 )Pt(μ‐PPh 2 )(μ‐I)Pt(μ‐PPh 2 )(μ‐I)Pt(PPh 3 )(C 6 F 5 )] ( 122 )96 (Scheme ) are linear triplatinum species not containing Pt–Pt bonds, whereas [(C 6 F 5 )(PPh 3 )Pt(μ‐PPh 2 )(μ‐H)Pt(μ‐PPh 2 )(μ‐H)Pt(PPh 3 )(C 6 F 5 )] ( 123 ) and [(H)(PH t Bu 2 )Pt(μ‐P t Bu 2 )(μ‐H)Pt(μ‐P t Bu 2 )(μ‐H)Pt(H)(PH t Bu 2 )] ( 124 ) are polyhydridic species endowed with two Pt–Pt bonds (Scheme ). Dihydride 123 forms together with 63 ,45 whereas tetrahydride 124 is obtained, after work‐up, by NaBH 4 reduction of trans ‐[PtCl 2 (PH t Bu 2 ) 2 ] 97. Oxidation of the 48 e trimer [(C 6 F 5 ) 2 Pt(μ‐PPh 2 ) 2 Pt(μ‐PPh 2 ) 2 Pt(C 6 F 5 ) 2 ] 2– ( 125 ) yields the 46 e species [(C 6 F 5 ) 2 Pt 1 (μ‐PPh 2 ) 2 Pt 2 (μ‐PPh 2 ) 2 Pt(C 6 F 5 ) 2 ] (Pt 1 –Pt 2 ) ( 126 ) for which a dynamic process renders equivalent the pentafluorophenyl groups in solution at room temperature 98.…”

Synthesis and Reactivity of the Unsaturated Trinuclear Phosphanido Complex [(C6F5)2Pt(μ-PPh2)2Pt(μ-PPh2)2Pt(PPh3)]

“…We are engaged in the synthesis of polynuclear platinum and/or palladium phosphanido complexes, and the judicious choice of the starting materials and reaction processes has allowed the rational synthesis of phosphanido complexes of different nuclearity with or without a metal–metal bond, with the latter depending on the total valence electron count (VEC). − Typically, polynuclear platinum or palladium complexes that contain 16 electrons per metal center, i.e., a VEC of 16 n ( n = number of metal centers), are considered to be saturated and do not require the presence of any metal–metal bond. For instance, in binuclear phosphanido complexes studied by us, the elimination of a pair of electrons, either via one-electron oxidation of each metal center or by elimination of one ligand, results in both cases in the formation of a Pt–Pt bond. ,,, When a ligand is eliminated in the resulting binuclear complex, one of the Pt centers is only three-coordinated.…”