Crystal and molecular structure of [1,2-bis(diphenylphosphino)hexafluorocyclopentene]dinitrosyliron

Abstract

Crystals of [1,2-bis(diphenylphosphino)hexafluorocyclopentene]dinitrosyliron, Ph₂P[graphic omitted]F₂·Fe(NO)₂, are monoclinic, a= 10·342, b= 17·364, c= 16·019 Å, β= 92·46°, Z= 4, space group P2₁/n. The structure was determined by Patterson and Fourier syntheses and refined by use of block-matrix least-squares calculations to R 0·044 for 2492 observed reflexions. The co-ordination geometry around the iron atom is that of a distorted tetrahedron; the N–Fe–N angle, 125·4°, is larger, while the P–Fe–P angle, 86·8°, is smaller than the tetrahedral value. The iron–nitrogen–oxygen groupings are essentially linear (177·8 and 176·8°), with Fe–N 1·661(7) and 1·645(7)Å, and N–O 1·184(10) and 1·177(10)Å. The short Fe–N and relatively long N–O distances indicate a considerable amount of metal to ligand back-donation through the NO π* orbitals.