Major improvements in the synthesis of 1 1 4 4-tetrafluorobutatriene (1) are presented Despite many attempts to isolate new metal complexes of 1 only an iron complex containing a ligand which is composed of a partially hydrolyzed tetrafluorobutatriene-dimer and carbon monoxide could be isolated and characterized by X-ray crystallography Certain metal centers and solvents accelerate the decomposition of 1 First attempts to synthesize 1 1-difluorobutatriene (2) are presented which underline the major challenges of a successful synthesis of 2 (C) 2010 Elsevier B V All rights reserved