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In fluorinated aromatic amine sourcing and application, one recurring operational problem is incorrect mass-to-volume conversion. Engineers, formulators, and procurement teams frequently rely on approximate values when charging reactors, designing storage systems, or calculating logistics loads. For compounds such as 4-fluoroaniline, even small density deviations can propagate into dosing errors, yield losses, or compliance discrepancies in regulated industries such as pharmaceuticals and agrochemicals. Understanding the true density and its practical implications is therefore not an academic detail but a day-to-day operational necessity.
The density of 4-fluoroaniline is approximately 1.12 g/cm³ at 25 °C, making it slightly denser than water and typical aniline derivatives. This value is widely used for industrial calculations, safety documentation, and process design involving this compound.
Before relying on this number in production or procurement decisions, it is essential to understand how density is defined, why it varies, and how it impacts real-world applications across chemical value chains.
Chemical Identity and Context of 4-Fluoroaniline
4-Fluoroaniline, also known as p-fluoroaniline, is a para-substituted fluorinated aromatic amine with the molecular formula C₆H₆FN and CAS No. 371-40-4. Structurally, it combines an electron-donating amino group with a fluorine atom positioned opposite on the benzene ring. This arrangement produces a relatively symmetrical molecule with predictable physical behavior compared to ortho- or meta-isomers.
From an industrial perspective, density is one of the most frequently referenced physical properties of 4-fluoroaniline, alongside boiling point, melting point, and solubility. Unlike spectroscopic identifiers, density directly affects how much material is actually being handled at every stage—from raw material storage to final reaction charging.
Standard Density Value and Reference Conditions
Under standard reference conditions used by most suppliers and regulatory bodies, 4-fluoroaniline has a density of approximately 1.12 g/cm³ at 25 °C. This value is typically determined using calibrated pycnometers or digital density meters and is reported in Safety Data Sheets and technical specifications.
The table below summarizes key identity and density-related data used in industrial documentation.
| Parameter | Value |
|---|---|
| Chemical name | 4-Fluoroaniline |
| CAS number | 371-40-4 |
| Molecular formula | C₆H₆FN |
| Molecular weight | 111.12 g/mol |
| Density (25 °C) | ~1.12 g/cm³ |
| Physical state | Liquid near room temperature |
This density places 4-fluoroaniline slightly above water (1.00 g/cm³) and marginally higher than unsubstituted aniline, reflecting the contribution of fluorine to molecular mass and intermolecular interactions.
Why Density Matters in Practical Applications
In real industrial settings, density is far more than a datasheet line item. It directly influences material handling accuracy, process safety, and economic efficiency. When 4-fluoroaniline is used as an intermediate in pharmaceutical or agrochemical synthesis, it is commonly dosed by volume for operational convenience. Any mismatch between assumed and actual density translates into stoichiometric error.
For example, charging 100 liters of 4-fluoroaniline based on an assumed density of 1.05 g/cm³ instead of 1.12 g/cm³ results in a mass shortfall of approximately 7 kilograms. In multi-step synthesis routes, such an error can significantly reduce yield or alter impurity profiles.
Density also affects storage tank calibration, pump selection, and transport documentation. Logistics providers rely on density to calculate total shipment weight, which in turn impacts freight cost, container selection, and compliance with transport regulations.
Temperature and Purity Effects on Density
Although 1.12 g/cm³ is widely accepted as the nominal density of 4-fluoroaniline, professionals should be aware that this value is temperature-dependent. Like most organic liquids, 4-fluoroaniline expands as temperature increases, leading to a gradual decrease in density.
Additionally, purity level plays a measurable role. Technical-grade material containing trace solvents or by-products may exhibit a slightly lower or higher density than high-purity material used in pharmaceutical synthesis. For critical applications, suppliers typically provide density ranges, such as 1.11–1.13 g/cm³, along with the measurement temperature.
The table below illustrates typical density variation considerations.
| Factor | Impact on Density |
|---|---|
| Temperature increase | Density decreases |
| Lower purity | Density may shift slightly |
| Dissolved impurities | Can increase or decrease density |
| Measurement method | Minor variability |
Understanding these factors allows engineers and chemists to apply appropriate correction factors during scale-up or quality control.
Comparison with Other Fluoroaniline Isomers
Density differences also help distinguish 4-fluoroaniline from other positional isomers, although these differences are subtle. Ortho- and meta-fluoroaniline isomers exhibit slightly different densities due to steric effects and packing efficiency in the liquid phase. While density alone is not sufficient for definitive identification, it serves as a supporting parameter alongside spectroscopic analysis.
| Compound | Approximate Density (25 °C) |
|---|---|
| 2-Fluoroaniline | ~1.10 g/cm³ |
| 3-Fluoroaniline | ~1.11 g/cm³ |
| 4-Fluoroaniline | ~1.12 g/cm³ |
Such comparisons are particularly useful in quality audits and incoming material inspections.
Safety, Regulatory, and Documentation Relevance
From a regulatory standpoint, density is a required parameter in Safety Data Sheets (SDS) and is referenced in hazard assessments, spill response planning, and transport documentation. Accurate density reporting under CAS No. 371-40-4 ensures alignment with frameworks such as REACH, TSCA, and GHS.
In emergency response scenarios, density determines whether a liquid will float or sink in water and influences containment strategies. For 4-fluoroaniline, being denser than water means it will tend to sink, a factor that must be considered in spill management planning.
Summary
The density of 4-fluoroaniline is approximately 1.12 g/cm³ at 25 °C, a value that underpins accurate dosing, safe handling, and compliant trade. While seemingly simple, this parameter has far-reaching implications across chemical manufacturing, logistics, and regulatory compliance. Professionals working with fluorinated aromatic amines should always verify density values against supplier documentation and adjust for temperature and purity where precision matters.
Source 4-Fluoroaniline with Confidence from Sparrow-Chemical
If your operations require 4-fluoroaniline with clearly documented physical properties and consistent batch quality, Sparrow-Chemical provides export-ready fluorinated intermediates supported by complete SDS and COA documentation. Visit https://sparrow-chemical.com/ to discuss specifications, density data at specific temperatures, and long-term supply solutions tailored to your industry.
