Acetyl Bromide: Detailed Product Description and Safety Overview

What is Acetyl Bromide?

Acetyl Bromide stands out as a distinct chemical compound combining an acetyl group with bromine. Its chemical formula, CH₃COBr, often prompts discussions about its reactivity and industrial value. This substance shows up as a colorless or pale yellow liquid with a strong, pungent smell that’s hard to forget. If you have spent any time in an organic chemistry lab, you know its vapor bites the nose and stings the eyes about as fast as ammonia, signaling its powerful nature. The compound comes up frequently in research and production settings as a fast-reacting acylating agent. Practical uses span pharmaceuticals, fine chemicals, and advanced materials.

Physical and Chemical Properties

From a property standpoint, Acetyl Bromide boils at roughly 81°C, and its density measures around 1.66 g/cm³ at 20°C. This density is noticeably higher than water, so the liquid sinks rather than floats if poured into a beaker with water. The acetyl group makes it reactive toward nucleophiles, and the bromine atom makes it particularly aggressive, much more so than the chloride cousin, Acetyl Chloride. In your hand, if you ever had crystals form from a cold bottle (rare, since it’s mainly liquid under standard conditions), you’d recognize a highly volatile system, with solidification only kicking in beneath -96°C. The compound’s critical property is its rapid reaction with water, producing hydrobromic acid and acetic acid, which leads to clouds of white vapor — not something anyone wants to breathe in.

Molecular Structure

Acetyl Bromide’s structure is straight to the point: a methyl group, a carbonyl in the center, and bromine on the other side. The concise formula, CH₃COBr, translates to a linear molecule with the carbonyl carbon at its heart, bridging the methyl’s softness and the bromine’s stubbornness. Its molar mass clocks in at about 122.95 g/mol. This straightforward layout allows it to act as a nimble acylating agent, slicing into organic compounds and modifying them quickly. Anyone who’s mixed it in a flask understands that its agility can be a blessing for efficiency and a curse for safety.

Commercial Forms, Specifications, and HS Code

As a commercial material, Acetyl Bromide comes primarily in liquid form, typically shipped in tightly sealed containers made of compatible materials to avoid dangerous leaks or reactions. Solid, powdered, flake, pearl, or crystal forms are not practical, thanks to its volatility and low freezing point. Solutions, occasionally prepared for laboratory or synthetic routes, need stabilization and quick use. Material specifications demand high purity, often greater than 98%, since impurities can encourage side reactions or instability during storage. Quality checks involve gas chromatography and spectroscopic analysis. The Harmonized System Code (HS Code) for Acetyl Bromide generally falls under 29153900, referring to acyclic acid halides, which customs authorities use to regulate and tax global shipments.

Density, Storage, and Handling

Pouring Acetyl Bromide reveals a heavy, mobile liquid, with density values standing at about 1.66 g/cm³. Storing it turns into a game of vigilance: temperature must stay steady, since a bump in room heat spikes vapor pressure, causing bottle seals to pop. Labs tend to keep it in cool, ventilated areas in tightly closed containers. Moisture spells disaster, triggering an exothermic hydrolysis reaction that releases hazardous vapors. You see safety mindsets sharpen whenever a bottle appears, with researchers checking gloves, fume hood functionality, and even backup gas scrubbers in case of a spill.

Hazards and Harmful Effects

Calling Acetyl Bromide hazardous doesn’t overstate the case. Inhaling vapors results in immediate respiratory distress, coughing, and a suffocating feeling. Skin contact burns and blinds if it gets in the eye. This isn’t just personal experience—medical data shows burns on exposed skin, chronic respiratory issues in unprotected workers, and dangerous synergistic reactions with solvents or strong bases. Agencies such as OSHA and NIOSH flag it under hazardous substance lists, with strict exposure limits. Accidents involving acid halides create headlines for a reason; past incidents show that poor planning, lack of proper PPE, or inadequate ventilation lead directly to emergency room visits or worse.

Uses and Raw Material Sourcing

Assembling Acetyl Bromide in industry usually means feeding acetic anhydride into a bromination process, or combining acetyl chloride with potassium bromide under specific conditions, with continual monitoring for runaway reactions. Labs often need the pure compound as an acylating agent, exploiting its ability to introduce acetyl groups into alcohols, amines, and phenols at lower temperatures than can be achieved with alternatives. Formulation work happens mostly in pharmaceutical companies, dye manufacturers, or specialty chemical houses, driven by demand for rigorous specificity and high yield. R&D chemists value its sharp selectivity, yet curse the long cleanup and neutralization steps following a reaction run.

Solutions for Safer Handling and Use

Living with Acetyl Bromide demands more than basic PPE. Splash goggles, acid-resistant gloves, and chemical-resistant aprons come standard. The lab where I trained relied on efficient fume hoods backed by active carbon filters to grab stray vapors. Training makes the biggest difference, with drills for spill containment, emergency eyewash, and neutralization protocols using sodium bicarbonate. Manufacturers have moved toward smaller packaging, pre-measured ampules, and digital inventory systems to cut human error during transfer and weighing. Industry watchdogs press for stricter storage regulations by integrating digital temperature and humidity monitors, along with more transparent Material Safety Data Sheet dissemination. Where possible, green chemistry alternatives reduce reliance on acid bromides, shifting synthetic approaches toward less hazardous intermediates or catalytic pathways. People working with Acetyl Bromide know that progress rides on a blend of caution, education, and a willingness to replace old methods as safer options emerge.