The structure of the title compound, [Fe(C5H5)(C15H13O2)], consists of a ferrocenyl moiety and a 2-methoxyphenyl group linked through a prop-2-en-1-one spacer in anEconformation. In the ferrocene unit, the substituted cyclopentadienyl (Cps) ring and the unsubstituted cyclopentadienyl ring (Cp) are almost parallel to one another [dihedral angle = 1.78 (14)°], and the Cp and Cps rings are in agaucheconformation. The benzene ring is twisted by 10.02 (14) and 11.38 (11)° with respect to the Cp and Cps rings, respectively. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains running along theb-axis direction.

The title ferrocene derivative, [Fe(C5H5)2(C8NO2)], including an alkyne bonded to a para-nitrophenyl substituent, which was synthesized from a copper-free Sonogashira cross-coupling reaction between ethynylferrocene and 4-bromo-1-nitrobenzene, crystallizes in the P21/n space group. In the ferrocene unit, the pentadienyl (Cps) rings are in an eclipsed conformation. The angle of rotation between the substituted cyclopentadienyl ring and the p-nitrophenyl group is 6.19 (10)°, yielding a quasi-linear extension of the ferrocenyl substitution. Important intermolecular interactions arise from π–π stacking between the Cp rings and the p-nitrophenyl, from corners of the Cp rings that are perpendicularly aligned, and between the O atoms from the nitro substituent and carbons at the corners of the Cp rings, propagating along all three crystallographic axes.