337526-17-7Relevant articles and documents
Reduction of (imine)Pt(IV) to (imine)Pt(II) complexes with carbonyl-stabilized phosphorus ylides
Wagner,Pakhomova,Bokach,Frausto da Silva,Vicente,Pombeiro,Kukushkin
, p. 1683 - 1689 (2008/10/08)
A novel method is reported for generation of the difficult-to-obtain (imine)Pt(II) compounds that involves reduction of the corresponding readily available Pt(IV)-based imines by carbonyl-stabilized phosphorus ylides, Ph3P= CHCO2R, in nonaqueous media. The reaction between neutral (imino)Pt(IV) compounds [PtCl4{NH=C(Me)-ON=CR1R2}2] [R1R2 = Me2, (CH2)4, (CH2)5, (Me)C(Me)=NOH], [PtCl4{NH=C(Me)ONR2}2] (R = Me, Et, CH2Ph), [PtCl4{N=C(Me)O-N(R3)-C(R1) (R2)}2] (R1 = H; R2 = Ph or C6H4Me; R3 = Me) as well as anionic-type platinum(IV) complexes (Ph3PCH2Ph)[PtCl5{NH=C(Me) ON=CR2}] [R2 = Me2, (CH2)4, (CH2)5] and 1 equiv of Ph3P=CHCO2R (R = Me, Et) proceeds under mild conditions (ca. 4 h, room temperature) to give selectively the platinum(II) products (in good to excellent isolated yields) without further reduction of the platinum center. All thus prepared compounds (excluding previously described Δ4-1,2,4-oxadiazoline complexes) were characterized by elemental analyses, FAB mass spectrometry, IR and 1H, 13C{1H}, 31P(1H} and 195Pt NMR spectroscopies, and X-ray single-crystal diffractometry, the latter for [PtCl2{NH=C(Me)ON=CMe2}2] [crystal system tetragonal, space group P42/n (No. 86), a = b = 10.5050(10) A, c = 15.916(3) A] and (Ph3PCH2CO2-Me)[PtCl3(NCMe)] [crystal system orthorhombic, space group Pna21 (No. 33), a = 19.661(7) A, b = 12.486(4) A, c = 10.149(3) A]. The reaction is also extended to a variety of other Pt(II)/Pt(IV) couples, and the ylides Ph3P=CHCO2R are introduced as mild and selective reducing agents of wide applicability for the conversion of Pt(IV) to Pt(II) species in nonaqueous media, a route that is especially useful in the case of compounds that cannot be prepared directly from Pt(II) precursors, and for the generation of systematic series of Pt(II)/Pt(IV) complexes for biological studies.
