Reactivity of silyl-substituted heterobimetallic iron–platinum hydride complexes towards unsaturated molecules: Part II. Insertion of trifluoropropyne and hexafluorobutyne into the platinum–hydride bond

Insertion of hexafluorobutyne into the Pt–H bond of the heterobimetallic complexes [(OC)3Fe{Si(OMe)3}(μ-Ph2PXPPh2)Pt(H)(PPh3)] (1a X = CH2; 1b X = NH) yields the σ-alkenyl complexes [(OC)3Fe{μ-Si(OMe)2(OMe)}(μ-Ph2PXPPh2)Pt{C(CF3)double bond; length as m-dashC(H)CF3}] (3a X = CH2; 3b X = NH). This insertion reaction is accompanied by dissociation of the platinum bound PPh3 ligand and saturation of the vacant coordination site by a dative μ−η2-Si–O → Pt interaction. Addition of the Pt–H bond of 1a across the triple bond of 3,3,3-trifluoropropyne affords in a regiospecific manner [(OC)3Fe{μ-Si(OMe)2(OMe)}(μ-dppm)Pt{C(CF3)double bond; length as m-dashCH2}] (2) having the trifluoromethyl substituent on the α-carbon. Addition of RNtriple bond; length of mdashC to 3 affords the isocyanide adducts [(OC)3Fe{Si(OMe)3}(μ-Ph2PXPPh2)Pt(CNR){C(CF3)double bond; length as m-dashC(H)CF3}] (4a R = t-Bu, X = CH2; 4b R = 2,6-xylyl, X = CH2; 4c R = 2,6-xylyl, X = NH). In dichloromethane solution 3a is gradually transformed into the C4F6-bridged compound [(OC)3Fe(μ-dppm)(μ-CF3Cdouble bond; length as m-dashCCF3)Pt(CO)] 5. The Pt-bound carbonyl ligand of 5 is displaced by xylylisocyanide or trimethylphosphite affording the derivatives [(OC)3Fe(μ-dppm)(μ-CF3Cdouble bond; length as m-dashCCF3)Pt(CNxylyl)] 6 and [(OC)3Fe(μ-dppm)(μ-CF3Cdouble bond; length as m-dashCCF3)Pt{P(OMe)3}] 7. The molecular structures of 4a, 5 and 6 have been determined by X-ray diffraction studies.