Addition of copper(I) and silver(I) to a P-P bond in [(triphos)MP3] [triphos=1,1,1- tris(diphenylphosphinomethyl)ethane;: M=Co, Rh] -: X-ray crystal structure of [{(triphos)CoP3}2Cu]PF6

Treatment of the [(triphos)MP3] compounds [triphos = 1,1,1-tris(diphenylphosphinomethyl)ethan; M=Co, Rh], which have a pseudotetrahedral core formed by three unsubstituted phosphorus atoms and a cobalt group metal fragment, with copper(I) and silver(I) derivatives affords the compounds [{(triphos)MP3}(2)M']Y (M=Co, M'=Cu, Y=BF4, PF6; M'=Ag, Y=ClO4, PF6. M=Rh, M'=Ag, Y=CF3SO3, PF6). X-ray crystallographic analysis of the [{(triphos)CoP3}(2)Cu]PF6 derivative shows that the copper atom is bound to two pairs of unsubstituted phosphorus atoms belonging to the P-3 units of two [(triphos)CoP3] fragments; the copper atom has a co-ordination geometry intermediate between elongated tetrahedral and square planar. The same structure is assigned to all the complexes on the basis of P-31{H-1} NMR data which are indicative of dynamic behaviour of the compounds in solution. The unexpected elimination of phosphane ligands from copper(I) and silver(I) parent salts and the lengthening of the P-P bonds to which addition of the M' metal occurs is indicative of significant interaction between the metal and the MP3 clusters. (C) 1999 Elsevier Science Ltd. All rights reserved.