Crystal structures of the difluorophosphate complexes, Co(O2PF2)2·2MeCN and Cu(O2PF2)2

Abstract

The structures of two new difluorophosphates, Co(O2PF2)2·2MeCN and Cu(O2PF2)2, have been determined from single-crystal X-ray data. The former crystallises in the space group Cmca, Z= 4, with a= 9.227(4), b= 13.871(5), and c= 9.471(4)A, and the structure has been refined to R= 0.046 for 489 observed reflections. The compound is polymeric with bridging difluorophosphate groups, with the cobalt atom in octahedral co-ordination to four oxygen atoms and two nitrogen atoms from the traps oriented acetonitrile molecules. The copper compound belongs to the space group Fddd, Z= 48, with a=10.134(4), b= 24.495(9), and c= 34.058(10)A, and the refinement converged at R= 0.067 for 1 587 observed reflections. It also has a polymeric structure with two independent copper atoms and bridging difluorophosphate groups. Each copper atom has four near oxygen neighbours but distorted-octahedral co-ordination is completed by two longer contacts to oxygen atoms of symmetry-related difluorophosphate groups. This tridentate function for the difluorophosphate group has not previously been observed.