DIPHENYLPHOSPHINE AND DIPHENYLPHOSPHIDO DERIVATIVES OF [RU3(MU-H)(MU-3-AMPY)(CO)9] (HAMPY=2-AMINO-6-METHYLPYRIDINE)

The reactions of [Ru3(μ-H)(μ-ampy)(CO)9] (1) (Hampy = 2-amino-6-methylpyridine) with one or two equivalents of PPh2H lead to the complexes [Ru3(μ-H)(μ3-ampy)(CO)8(PPh2H)] (2) or [Ru3(μ-H)(μ3-ampy)(CO)7(PPh2H)2] (3), in which the PPh2H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 2 can be transformed in refluxing THF into the phosphido-bridged derivative [Ru3(μ3-ampy)(μ-PPh2)(μ-CO)2(CO)6] (4), which contains the PPh2 ligand spanning one of the two RuRu edges unbridged by the amido moiety, and presents an extremely high 31P chemical shift of 386.9 ppm. Under similar conditions, complex 3 gives a mixture of two isomers of [Ru3(μ-H)(μ3-ampy)(μ-PPh2)2(CO)6] in a 5:1 ratio; the major product (5) has a plane of symmetry, whereas the minor one (6) is asymmetric. © 1990.