Unprecedented pentanuclear mixed-valence Pt(II)-Pt(IV) complex anion in Q2[Pt5Cl20] salts (Q = TBA, PPN)

Abstract

Red crystals of [TBA] 2 [Pt 5 Cl 20 ] were obtained by reacting [TBA] 2 [PtCl 6 ] with an excess of AlCl 3 at room temperature in CH 2 Cl 2. The salt [PPN] 2 [Pt 5 Cl 20 ] containing the same anion was prepared by reaction of platinum tetrachloride with a small excess of [PPN]Cl in 1,2-dichloroethane at room temperature. Single crystal X-Ray diffraction studies confirmed that both species contained the mixed-valence [Pt 5 Cl 20 ] 2anion with two dinuclear platinum (IV) Pt 2 Cl 10 fragments organized around a central square planar platinum (II) in a chair arrangement.

Platinum Nanoparticle Formation Kinetics and Mechanistic Studies: Evidence for an Alternative 4-Step Mechanism Involving Size-Dependent Growth and Chloride Anion and Room-Dust-Dependent Nucleation

“…Nanoparticles (NPs) composed of Pt, Pd, Ir, Rh, or other transition metals have catalytic, medicinal, energy, and environmental applications that invariably depend on their size, particle size distribution (PSD), and shape. − Platinum NPs (Pt 0 n ) have been extensively studied due to their high catalytic activity compared to bulk Pt 0 metal as well as other applications that range from uses in biotechnology to optoelectronics. − While control over Pt 0 n size and PSD has been probed empirically via the choice of precursor, ligands, temperature, concentration, pressure, reducing agent, and solvent, ,− the majority of reports still rely on trial-and-error based, hence mechanistically unoptimized, syntheses. At present, a more broadly applicable − Pt 0 n NP formation mechanism remains unclear, ,− despite Pt 0 n being an important, widely employed nanomaterial. ,,− Hence, obtaining the underlying mechanism(s) of particle formation process including its nucleation, growth, and any extant aggregation steps remains important and is continued herein for the specific case of Pt 0 n NPs.…”

Synthesis and characterization of binuclear Pt(IV) complexes and tetranuclear mixed valence complexes of Platinum(II)-Platinum(IV)

“…Also, a small amount of discrete bi-, tri-, and tetranuclear mixed-valence platinum(II)platinum(IV) complexes have been described [24][25][26][27][28][29][30]33,[36][37][38][39][40][41][42].…”

“…In addition, [Pt 3 X 12 ] 2-(X= Cl, Br) are trinuclear platinum(II)-platinum(IV) mixed valence complexes [26], and they consist in three linearly arranged platinum atoms (Pt IV -Pt II -Pt IV ) connected by halo-bridging ligands. The chloridecompound was isolated from a mixture of Pt(IV) complexes, probably being the result of the reductive elimination of Cl 2 from the [Pt 3 Cl 14 ] 2anion at the central platinum atom, while the bromide derivative has been deliberately synthesized by reaction between [PtBr 6 ] 2and [PtBr 4 ] 2in 2:1 ratio, Very recently, Belli Dell´Amico et al have published the synthesis and structural characterization of the pentanuclear mixed-valence Pt(II)-Pt(IV) complex anion [Pt 5 Cl 20 ] 2which has been prepared by using Pt(IV) derivatives as starting materials [42].…”