Crystal Structure of 1,2,4,1',2',4'-Hexamethylferrocene

Abstract

The crystal structure of 1,2,4,1′,2′,4′-hexamethylferrocene (Me6Fcsym) was determined by X-ray diffraction. In the Me6Fcsym molecule, the C5 rings occur in the staggered conformation. The Fe–(C5 ring center) bond length tends to increase in the series Me2Fcsym, Me6Fcsym, Me8Fcsym, and Me10Fcsym. The relative conformations of the vicinal Me groups in the Me6Fcsym, Me8Fcsym, and Me10Fcsym molecules and the pattern of variation of the 1H and 13C NMR signals of the Me groups in the series of polymethylferrocenes MenFcsym (n = 2, 4, 6, 8, 10) compared with the methylbenzene analogues indicates that Me groups in symmetric polymethylferrocenes are not coupled, but are relatively free to rotate around the C(C5 ring)–C(Me) bond (CIF file CCDC no. 1436882).