Polynuclear homo- or heterometallic palladium(II)-platinum(II) pentafluorophenyl complexes containing bridging diphenylphosphido ligands. 22. From a trinuclear platinum(III) phosphido derivative to a platinum(II) cluster: Formation of a P-C bond

摘要

Reaction of the trinuclear Pt-III - Pt-III - Pt-II [(C6F5)(2)Pt-III(mu-PPh2)(2)Pt-III(mu-PPh2)(2)Pt(C6F5)(2)] ( 2) derivative with NBu4Br or NBu4I results in the formation of the trinuclear Pt-II complexes [NBu4][(PPh2C6F5)(C6F5)Pt(mu-PPh2)(mu-X) Pt(mu-PPh2)(2)Pt( C6F5)(2)] [X = I ( 3), Br (4)] through an intramolecular PPh2/C6F5 reductive coupling and the formation of the phosphine PPh2C6F5. The trinuclear Pt-II complex [(PPh2C6F5)(C6F5) Pt(mu-PPh2) Pt(mu-PPh2)(2)Pt(C6F5)(2)] ( 5), which displays two Pt - Pt bonds, can be obtained either by halide abstraction in 4 or by refluxing of 2 in CH2Cl2. This latter process also implies an intramolecular PPh2/C6F5 reductive coupling. Treatment of complex 5 with several ligands (Br-, H-, and CO) results in the incorporation of the ligand to the cluster and elimination of one (X = H-) or both (X = Br-, CO) Pt - Pt bonds, forming the trinuclear complexes [NBu4][(PPh2C6F5)(C6F5) Pt(mu-PPh2)(mu-X) Pt(mu-PPh2)(2)Pt( C6F5)(2)] [X = Br ( 6), H (7)] or [(PPh2C6F5)(C6F5) Pt(mu-PPh2)(2)Pt(mu-PPh2)(CO) Pt(C6F5)(2)(CO)] ( 8). The structures of the complexes have been established on the basis of H-1, F-19, and P-31 NMR data, and the X-ray structures of the complexes 2, 3, 5, and 7 have been established. The chemical relationship between the different complexes has also been studied.