Complexes Containing Bridging PF2 Ligands

The first complex of this type was reported by Kruck and Lang (205) who obtained the red liquid compound [Co2(PF3)6(/i-PF2)2] (2) by heating CoI2 and copper at 170°C with high-pressure (400 atm) PF3 (method A). The structure (2) was elucidated by 19F NMR spectroscopy. 

The structurally related bright-red crystalline iron compound [Fe2(PF3)6(/i-PF2)2] has been obtained by Timms by metal vapor synthesis (method B) in which iron atoms and PF3 are cocondensed at liquid nitrogen temperature (340, 341). A similar reaction using cobalt 

In marked contrast to the large number of polynuclear metal carbonyl complexes known there are as yet relatively few reports of analogous polynuclear (i.e., containing more than two metal atoms) transition metal-PF3 complexes. Triftuorophosphine can displace up to half the coordinated CO ligands in [Ru3(CO)12] (method A) before the metal cluster is broken and mononuclear complexes are formed. 

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