BIS(DIPHENYLPHOSPHINO)METHANE-SUBSTITUTED PRODUCTS FROM (μ3-CCH3)CO3(CO)9

The reaction between the alkylidyne cluster (μ₃-CCH₃)Co₃(CO)₉ and bis(diphenylphosphino) (dppm) gives two disubstituted stereoisomers of formula (μ₃-CCH₃)Co₃(CO)₇(μ-PPh₂CH₂PPh₂) (I and II) and one monosubstituted product containing an uncoordinated phosphoryl group, (μ₃-CCH₃)Co₃(CO)₈[PPh₂-CH₂P(O)Ph₂] (III). On heating in toluene under reflux, the kinetically favoured isomer I is transformed into the thermodynamically stable isomer II. Further reaction with a second molecule of dppm gives rise to two derivatives, (μ₃-CCH₃)CO₃(CO)₅(μ-dppm)₂ (IV) and (μ₃-CCH₃)Co₃(CO)₆(μ-dppm)(dppm) (V). All the products have been characterized by IR and ¹³C and ³¹P NMR spectroscopy.