Structure of a cis-complex derived from tetracarbonylbis-π-cyclopenta-dienyldi-iron. Crystal and molecular structure of di-µ-carbonyl-µ-(1,2-Di-π-cyclopentadienyl-NNN′N′-tetramethylethylenediamine)-bis-(carbonyliron)

Abstract

The crystal structure of [Fe₂{π-C₅H₄·CH(NMe)₂CH(NMe)₂·C₅H₄}(CO)₄] has been determined by X-ray diffraction methods and refined by a least-squares procedure. The orthorhombic unit-cell (space group Pbca) has dimensions a= 14·957, b= 12·792, c= 20·128 Å for Z= 8. The molecule has the expected carbonyl-bridged structure with a cis-configuration of the cyclopentadienyl rings. The Fe₂(CO)₂ bridging group is not planar, being folded about the Fe–Fe axis, by 20·7°, away from the cyclopentadienyl rings. The Fe ⋯ Fe distance is 2·510 Å and the iron–carbonyl distances are 1·757 and 1·925 Å for the terminal and bridged groups respectively.