Crystal structure of an iron–antimony molecular complex bis-µ-[dicarbonyl(π-cyclopentadienyl)ferriochloro]-bis{[dicarbonyl(π-cyclopentadienyl)ferriochloro]trichloroantimony}

Abstract

Crystals of the title complex (I) are triclinic, space group P, with a unit cell of dimensions a= 12·513(3), b= 18·618(5), c= 10·899(3)Å, α= 104·20(2), β= 115·50(2), γ= 92·15(2)°, Z= 2. The structure was solved from diffractometer data by Patterson and Fourier methods and refined by least-squares methods to R 7·4%(2001 observed reflections).

Two crystallographically different ‘molecules’ of the title compound are found within the triclinic unit cell, each being independent and having a different crystallographic centre of symmetry.

Each ‘molecule’ consists of two SbCl₃ and two Fe(C₅H₅)(CO)₂Cl units, linked about a centre of symmetry by weak Sb ⋯ Cl bridges. In the SbCl₃ segment a distorted octahedron about antimony is completed by interactions from chlorine atoms from three surrounding Fe(C₅H₅)(CO)₂Cl groups (one terminal and two bridging). The Sb–Cl bonds vary from 2·351(10) to 2·404(9)Å, while the three bridging Sb ⋯ Cl interactions are 3·025(9)–3·307(9)Å. Fe–Cl bonds are 2·279(9) to 2·312(9)Å.