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[摘要]：The action of moisture on the homoleptic organoplatinum(II) compound [NBu4](2)[Pt(CF3)(4)] (1) gives rise to the carbonyl derivative [NBu4][Pt(CF3)(3)(CO)] (2), which is itself moisture stable. However, treatment of compound 2 with HCl(aq) results in the formation of [NBu4][cis-Pt-(CF3)(2)Cl(CO)] (3), which undergoes degradation of an additional CF3 group by further treatment with HCl(aq) in large excess, affording [NBu4][cis-Pt-(CF3)Cl-2(CO)] (4). The carbonyl derivatives 2-4 are fairly stable species, in which the CO ligand, however, can be readily extruded by reaction with trimethylamine N-oxide (ONMe3). Thus, compound 2 reacts with ONMe3 in the presence of a number of neutral or anionic ligands affording a series of singly or doubly charged derivatives with the general formulae [NBu4][Pt(CF3)(3)(L)] [L = CNtBu (5), PPh3 (6), P-(o-tolyl)(3) (7), tht (8; tht = tetrahydrothiophene)] and [NBu4](2)[Pt(CF3)(3)X] [X = Cl (9), Br (10), I (11)], respectively. Compound 2 also reacts with ONMe3 and pyridin-2-thiol (C5H5NS) giving rise to the five-membered metallacyclic derivative [NBu4][Pt(CF3)(2)(CF2NC5H4S-kappa C,kappa S)] (12), which can be viewed as a difluorocarbene species stabilized by intramolecular base coordination. On the other hand, treatment of compound 3 with ONMe3 in the presence of C5H5NS yields the four-membered metallacyclic compound [NBu4][Pt(CF3)(2)(NC5H4S-kappa N,kappa S)] (13). The geometries of the metallacycles in compounds 12 and 13 are compared. In the absence of any additional ligand, compound 3 undergoes dimerization producing the dinuclear species [NBu4](2)[{Pt(CF3)(2)}(2)(mu-Cl)(2)] (14). Halide abstraction in the latter compound with AgClO4 in THF yields the solvento compound cis-[Pt(CF3)(2)(thf)(2)] (15). The highly labile character of the THF ligands in compound 15 makes this species a convenient synthon of the "cis-Pt(CF3)(2)" unit. |
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