2,3-difluoro-4′-heptyl-4-iodobiphenyl

Description

2,3-difluoro-4′-heptyl-4-iodobiphenyl is a functionalised aromatic intermediate carrying a heptyl chain and two lateral fluorines on adjacent ring positions.

The aryl iodide is the electrophilic half of the cross-coupling pair: it undergoes oxidative addition to palladium, and it is equally the entry point to halogen-metal exchange when an aryllithium or Grignard reagent is wanted. Aryl iodides add to palladium faster than the matching bromides, which is what makes selective sequencing possible when one substrate carries two different halogens.

Key data

• Catalogue code: KC1033
• Molecular formula: C19H21F2I
• Molecular weight: 414.27 g/mol
• Category: Aromatics

What the substitution pattern does

The heptyl chain places this compound at n=7 in its homologous series. Chain length is not a cosmetic variable here: each added methylene lowers the melting point unevenly and shifts the balance between nematic and smectic order, because an odd-numbered chain sets its terminal bond at a different angle to the molecular long axis than an even one. Homologues therefore alternate in behaviour rather than trending smoothly, and an odd-numbered member frequently outperforms both of its neighbours for a given formulation.

Two fluorines on adjacent ring positions point their combined dipole across the molecular long axis, not along it. Lateral 2,3-difluorination is the standard route to negative dielectric anisotropy – the property required by vertically aligned display modes, where the field must reorient molecules that start out perpendicular to the substrate.

The biphenyl core supplies the rigid, elongated shape that mesophase formation requires. Its two rings twist out of coplanarity by roughly 40 degrees in the gas phase but flatten in condensed phases, and that adjustable conjugation is what makes biphenyls both mesogenic and optically anisotropic.

Typical applications

• formulation of negative-dielectric-anisotropy mixtures for VA display modes
• extension of rigid-core length in high-birefringence blends
• general intermediate for fine chemical and materials synthesis
• oxidative-addition partner in palladium-catalysed cross-coupling
• halogen-metal exchange to the aryllithium or Grignard reagent

Ordering

This compound is supplied to order. Pricing depends on quantity and on the specification you need, so it is quoted rather than listed – send an enquiry stating the quantity and any purity or analytical requirement, and you will receive a written quotation.

Handling and documentation

Supplied for laboratory and industrial use by trained personnel only. Not for use as a medicine, food, cosmetic or biocide, and not for administration to humans or animals. Safety documentation is issued with the order; this page is not a source of hazard information.