Crystal structure of 1-ferrocenyl-2-(4-nitro-phen-yl)ethyne

Area of Science:

• Organometallic Chemistry
• Crystallography
• Supramolecular Chemistry

Background:

• Ferrocene derivatives are versatile organometallic compounds with diverse applications.
• Sonogashira cross-coupling reactions are crucial for forming carbon-carbon bonds, particularly in synthesizing conjugated systems.

Purpose of the Study:

• To synthesize and characterize a novel ferrocene derivative with a para-nitro-phenyl substituent.
• To investigate the crystal structure and intermolecular interactions of the synthesized compound.

Main Methods:

• Copper-free Sonogashira cross-coupling reaction between ethynylferrocene and 4-bromo-1-nitro-benzene.
• Single-crystal X-ray diffraction analysis to determine the crystal structure and space group (P21/n).

Main Results:

• Successful synthesis of the ferrocene derivative [Fe(C5H5)2(C8NO2)].
• The ferrocene unit displays an eclipsed conformation of the cyclopentadienyl (Cp) rings.
• A quasi-linear arrangement was observed with a rotation angle of 6.19(10)° between the substituted Cp ring and the p-nitro-phenyl group.
• Significant intermolecular interactions, including pi-pi stacking and interactions between nitro group oxygen atoms and Cp ring carbons, were identified along all crystallographic axes.

Conclusions:

• The study presents a novel ferrocene derivative synthesized via a copper-free Sonogashira coupling.
• The crystal structure reveals specific conformational preferences and highlights the role of intermolecular forces in the solid-state arrangement.
• The findings contribute to understanding the structural diversity and intermolecular interactions in functionalized ferrocene systems.