55517-82-3

Upstream product

• 7789-46-0 iron(II) bromide 
• 102-54-5 ferrocene 
• 392-56-3 Hexafluorobenzene 
• 33272-09-2 1,1'-dilithioferrocene 

Relevant academic research and scientific papers

Synthesis and structural trends in pentafluorophenyl-substituted ferrocenes, 1,4-tetrafluorophenylene-linked diferrocenes, and 1,1′-ferrocenylene-1,4-tetrafluorophenylene co-oligomers

1,1′-Dilithioferrocene, or (CpLi)2Fe (1), reacts with excess C6F6 in THF to afford mostly (C6F5Cp)2Fe (2), accompanied by the diiron complex (C6F5Cp)FeCp(1,4-C6F4)CpFe(CpC 6F5) (3). The reaction of 1 with 1.0 equiv of C6F6 affords a mixture of sparingly soluble stepgrowth oligomers assigned to [-FeCp(1,4-C6F4)-]n (4). [1-Li-2-RNCp]FeCp (6, RN = CH2-NMe2) reacts with 1 equiv of C6F6 to afford [1-(C6F5)-2-RNCp]FeCp (7). Complex 6 reacts with 0.5 equiv of C6F6 to afford CpFe[2-RNCp](1,4-C6F4)[2-RNCp]FeCp as a mixture of two diastereomers (meso-8, major and dl-8, minor). The relative stereochemistry of meso-8 is established by crystallographic analysis of the corresponding bis(methiodide) (12). [1-Li-2-RNCp]Fe(CpLi) (9) reacts with excess C6F6 to afford mainly the diarylated ferrocene [1-(C6F5)-2-RNCp]Fe(CpC6F 5) (10). The reaction of 9 instead with 1.0 equiv of C6F6 affords a mixture of oligomeric species assigned to the formula [-(2-RNCp)FeCp(1,4-C6F4)-]n (11). In contrast to 4, 11 is sufficiently soluble for characterization by solution NMR spectroscopy (end group analysis), and under optimized conditions a number-averaged degree of oligomerization corresponding to a linear Fe9 species is determined. The complexes 3, 7, 10, and 12 are characterized by single-crystal X-ray diffraction. Crystalline 3 exhibits infinite π-stacking interactions composed of intramolecular triple-decker C6F5-C6F4-C6F5 stacking and intermolecular Cp-C6F5 stacking. The crystal structure of 10 also shows intramolecular arene stacking, but intermolecular Cp-C6F5 interaction is interrupted by the dimethylaminomethyl substituent. None of these complexes show intermolecular stacking among the various C6F5 and C6F4 groups. Extensive intermolecular C-H?F-C interactions in the crystallographic packing diagrams of 3, 7, 10, 12, and CpFeCpC6F4C6F4CpFeCp (13) are characterized as either purposeful or diffuse by examining correlations of their respective H?F distances and C-H?F angles. Solution voltammetry of 3 shows two unresolved, reversible FeII|FeIII couples, suggesting weak electronic communication between the two iron centers despite the fully conjugated structure.

Synthesis of pentafluorophenyl-substituted cyclopentadienes and their use as transition-metal ligands

The reaction of NaC5H5 (NaCp) and hexafluorobenzene (1:1 ratio) in THF at 25 °C for 15 h afforded, after hydrolysis, a mixture of regioisomeric (pentafluorophenyl)cyclopentadienes. This mixture was isolated as a monoisomeric dimer of 1-(pentafluorophenyl)cyclopentadiene. The structure of the dimer was determined crystallographically. Flash vacuum thermolytic cracking of the dimer at 200 °C regenerated (pentafluorophenyl)cyclopentadiene as a mixture of regioisomers. In contrast, the reaction of NaCp, NaH, and C6F6 (1:2:5 ratio) in THF at reflux for 3 d affords, after hydrolysis, 1,4-bis(pentafluorophenyl)cyclopentadiene, which does not dimerize. Either the mono- or the disubsubstituted diene reacts with NaH in THF to afford the corresponding stable substituted sodium cyclopentadienides in high yields. Sodium (pentafluorophenyl)cyclopentadienide, (C6F5)C5H4Na, reacted with FeBr2, Re(CO)5Br, and ZrCl4(THF)2, to afford the transition metal complexes (η5-C5H4C6F5) 2Fe, (η5-C5H4C6F 5)Re(CO)3, and (η5-C5H4C6F5) 2ZrCl2. Sodium 1,3-bis(pentafluorophenyl)cyclopentadienide reacted with FeBr2 and Re(CO)5Br to give the corresponding complexes [η5-1,3-C5H3(C6F 5)2]2Fe and [η5-1,3-C5H3(C6F 5)2]Re(CO)3. Infrared spectroscopic analysis of the tricarbonylrhenium(I) complexes and cyclic voltammetric analysis of the substituted ferrocenes quantified the strong electron-withdrawing effects of the pentafluorophenyl substituents.