Trimethylstannyl (diphenylphosphino)acetate: a source of (diphenylphosphino)acetate ligand in the synthesis of coordination compounds

Trimethylstannyl (diphenylphosphino)acetate (1), which is readily accessible from potassium (diphenylphosphino)acetate and trimethylstannyl chloride, may serve as the source of (diphenylphosphino)acetate anion in the preparation of coordination compounds. Thus, the reactions between M(cod)Cl₂] (M = Pd and Pt; cod = η²:η²-cycloocta-1,5-diene) and two equivalents of 1 give M(Ph₂PCH₂CO₂-κ²O,P)₂] (2 and 3), while the reaction of {Pd(μ-Cl)Cl(PFur₃)}₂] (4; Fur = 2-furyl) with one equivalent of 1 yields SP-4-3]-PdCl(Ph₂PCH₂CO₂-κ²O,P)(PFur₃)] (5). The reactions of 1 with the dimers {Rh(η⁵-C₅Me₅)Cl(μ-Cl)}₂] and {Ru(η⁶-1,4-MeC₆H₄(CHMe₂))Cl(μ-Cl)}₂] (at 1-to-metal ratio 1:1) produce O,P-chelated complexes as well, albeit as stable adducts with the liberated Me₃SnCl: RhCl(η⁵-C₅Me₅)(Ph₂PCH₂CO₂-κ²O,P)] · Me₃SnCl (6) andRuCl(η⁶-1,4-MeC₆H₄(CHMe₂))(Ph₂PCH₂CO₂-κ²O,P)] · Me₃SnCl (8). The related complexes with P-monodentate (diphenylphosphino)acetic acid, RhCl₂(η⁵-C₅Me₅)(Ph₂PCH₂CO₂H-κ,P)] (7) and RuCl₂(η⁶-1,4-MeC₆H₄(CHMe₂))(Ph₂PCH₂CO₂H-κP)] (9), were obtained by bridge splitting in the dimers with the phosphinocarboxylic ligand. All new compounds were characterized by spectral methods and combustion analyses, and the structures of 2 · 3CH₂Cl₂, 3, 4, 5, 6 and 8 were determined by X-ray crystallography.