New C,P-Cyclometalated Compounds of Platinum(II) and Platinum(IV) Derived from Tri-o-tolylphosphine

Abstract

The reaction between [trans-PtCl2(PhCN)2] (PhCN = benzonitrile) and tri-o-tolylphosphine rendered [Pt{CH2C6H4P(o-tolyl)2-C,P}(μ-Cl)]2 (1), a new C,P-cyclometalated compound of Pt(II). The treatment of 1 with AgClO4 (1: 2) in NCMe gave the mononuclear compound [Pt{CH2C6H4P(o-tolyl)2-C,P}(NCMe)2]ClO4 (2). Solutions probably containing the cation [Pt{CH2C6H4P(o-tolyl)2-C,P}(THF)2]+ (THF = tetrahydrofuran) reacted with sodium dimethyldithiocarbamate (NaS2CNMe2) and potassium ethyl xanthate (KS2COEt) in 1:1 molar ratio yielding the mononuclear complexes [Pt{CH2C6H4P(o-tolyl)2-C,P}(S2CR)] (R: NMe2 (3), OEt (4)). The molecular structure of 3 was determined by X-ray diffraction. The reactions of 3 and 4 with Cl2, Br2 and I2 gave the mononuclear Pt(IV) complexes [Pt{CH2C6H4P(o-tolyl)2-C,P}(S2CR)X2] (X: Cl, Br, I) (5−10). In each reaction a single product can be detected spectroscopically, indicating that the oxidative addition of halogens (X2) to 3 and 4 proceeds stereoselectively. The molecular structure of co...