Crystal and molecular structure of (vitamin-A aldehyde)tricarbonyliron

Abstract

(Vitamin-A aldehyde)tricarbonyliron, C₂₀H₂₈O Fe(CO)₃, crystallises from light petroleum in the triclinic system with a= 10·20, b= 14·65, c= 8·05 Å, α= 82·36, β= 88·10, and γ= 103·83°, in space group P, with Z= 2. A single-crystalX-ray analysis, based on diffractometer data, has converged R for 1296 independent reflexions to 0·083; the average estimated standard deviations in bond lengths are 0·01 Å(Fe–C) and 0·03 Å(C–C and C–O).

The tricarbonyliron group is bound to a cis-butadiene fragment of the polyene chain. The geometry of the co-ordinated polyene is compared in detail with that of the free ligand and the structure of the complex is related to that of other metal–diene systems.