The crystal structure of the 2-dimensional polymeric complexes dibromo(4,4′-bipyridyl)iron(II) and dichloro(4,4′-bipyridyl)iron(II) by powder X-ray and neutron diffraction

Abstract

The polymeric compounds Fe(4,4′-bipyridyl)X 2 (X=Br ( 1) and Cl( 2)) have been synthesised by the addition of a methanolic solution of 4,4′-bipyridine to a methanolic solution of the anhydrous iron halide. Powder X-ray and neutron diffraction measurements and Rietveld techniques were used for structural refinement: ( 1) Cmmm, a=12.4701(7) Å, b=11.5179(6) Å, c=3.8095(2) Å, V=547.15(5) Å 3, Z=2; ( 2) Cmmm, a=12.0242(12) Å, b=11.5078(13) Å, c=3.6632(5) Å, V=506.89(10) Å 3, Z=2. The structures consist of pseudo-octahedral, high-spin iron(II) units, linked by bidentate 4,4′-bipyridyl ligands along the b-axis and dihalide bridges along the c-axis to form 2-dimensional sheets.