1-Heptanethiol: Insight and Practical Commentary
Historical Development
The story of 1-Heptanethiol goes back to the steady march of organic chemistry throughout the twentieth century. Researchers looking for versatile thiols discovered that extending the carbon chain of alkanethiols, like butanethiol and hexanethiol, could tweak chemical properties in useful ways. Laboratories first isolated 1-Heptanethiol to understand its odor profile, surface activity, and metal-binding capabilities. Over decades, chemists in both academia and industry used this molecule for surface treatments and to test new analytical techniques. As industries pushed for new materials, they kept finding new applications for longer-chain organosulfur compounds, giving 1-Heptanethiol an ongoing role in the toolkit for both basic research and applied science.
Product Overview
1-Heptanethiol uses a straightforward seven-carbon chain with a terminal thiol group, shaping a molecule that's both accessible and useful. Chemists gravitate towards thiols like this during surface modification of metals, due to the strong bond formed with gold and similar metals. As a result, 1-Heptanethiol turns up as a staple in the fields of self-assembled monolayers (SAMs) and nanotechnology. It can slip into various blends to tweak surface energy, especially when gentle hydrophobicity or a soft sulfur presence help build better devices. I’ve seen labs regard it as a workhorse—not as flashy as shorter chain thiols for reactivity, or as tenacious as longer chains for stability, but reliable where balance matters.
Physical & Chemical Properties
1-Heptanethiol appears as a colorless to pale yellow liquid, with a notorious, persistent odor reminiscent of stronger thiols. The boiling point hovers around 179°C, and the density ends up near 0.84 g/cm³ at 20°C. Its thiol group provides high reactivity toward metals, especially gold and silver, forming durable bonds used in self-assembled layers. Solubility in most organic solvents gives it a wide berth for blending, but it stubbornly resists dissolving in water. This mix of volatility, reactivity, and solubility turns 1-Heptanethiol into a practical candidate for reactions needing both sulfur chemistry and hydrocarbon flexibility.
Technical Specifications & Labeling
Catalogs list 1-Heptanethiol under CAS number 111-31-9, with purity typically sitting above 98% for research uses. The chemical formula reads as C7H16S, and the IUPAC name is 1-Heptanethiol. Safety data sheets warn about its pungent smell and potential skin and eye irritation. Bottles often carry hazard statements about flammability and toxicity, and suppliers recommend using this thiol in well-ventilated spaces, always with gloves and goggles. Reliable suppliers provide batch-specific data sheets, including GC or NMR spectra, to prove purity and profile trace contaminants.
Preparation Method
Making 1-Heptanethiol on a lab scale involves nucleophilic substitution, usually starting from 1-bromoheptane or 1-chloroheptane. Chemists react these alkyl halides with sodium hydrosulfide or thiourea, then carry out a basic workup and purification by distillation. Industrial synthesis can ramp up using similar routes, sometimes adjusted to reduce waste or sidestep noxious byproducts. The process stays rooted in straightforward organic chemistry but requires careful handling of all intermediate and product odors—those thiol smells linger, and the best labs plan ventilation and hood time accordingly.
Chemical Reactions & Modifications
The main game with 1-Heptanethiol is the reactivity of its sulfhydryl group (–SH). This gives it a hook into gold, silver, and other coinage metals, where it forms strong sulfur-metal bonds, making it a prime candidate for SAMs in surface science. Oxidation of the thiol ends up making disulfides, a common reaction in biosensors or advanced materials. Alkylation and acylation transformations create tailored derivatives for specialty coatings, pharmaceuticals, and even molecular electronics. In the right hands, the hydrocarbon tail can also serve as a hydrophobic anchor in surfactant design, especially for emulsions where sulfur brings both stickiness and reactivity.
Synonyms & Product Names
1-Heptanethiol carries various aliases across catalogs and publications. Some chemists know it as n-Heptanethiol or Heptyl mercaptan. In regulatory records, it pops up under its IUPAC title. During procurement, companies sometimes tweak names for specific uses, but the core identifier remains the seven-carbon count and the lone thiol at the end.
Safety & Operational Standards
Anyone who’s handled 1-Heptanethiol knows it calls for respect. Thiols have a reputation in labs for their strong smell, but the risks go deeper. Skin contact can trigger irritation, and the liquid’s volatility means its fumes can linger or spread across a poorly ventilated bench. In my experience, routine use pairs with gloves, eye protection, and a working fume hood. Spills should get cleaned fast to avoid lingering odors. Disposal drives home the sulfur hazard; waste must travel down special chemical routes rather than regular drains, both to protect local water and to keep municipal workers from getting an unwelcome noseful of mercaptan.
Application Area
1-Heptanethiol’s bond-forming skill underpins its use in modifying gold surfaces for biosensors and electronics. In surface science, SAMs built from this thiol tune everything from wettability to corrosion resistance. Small molecule research explores its potential to direct crystal growth, stabilize nanoparticles, or tweak the mechanical properties of coatings. Outside the lab, companies employ it in rubber processing as a vulcanizing agent or tackifier, leveraging its sulfur to create strong links between polymer chains. Its use extends further in lubricants, anti-wear additives, and occasionally in pest control, where organic sulfur packs both punch and persistence.
Research & Development
Scientists continue to probe what longer-chain thiols can offer, with 1-Heptanethiol remaining a reference point for both performance and practicality. Groups exploring new sensor technology often rely on it for modifying electrode surfaces, fine-tuning selectivity by controlling surface chemistry. Nanomaterial researchers use its sulfur anchor to stabilize gold nanorods or direct growth in quantum dots. Every tweak in chain length reveals something fresh about boundary layer performance or toxicity—the kind of slow, steady refinement that keeps basic research interesting. Startups in advanced coatings look to thiols for smarter anti-fouling layers and self-healing materials, with fresh results bumping out of patent silos each year.
Toxicity Research
Concerns about thiol safety never quite fade, since strong odors signal low odor thresholds and toxicity risks. Review of toxicological data on 1-Heptanethiol reveals moderate acute toxicity in rodents, with primary effects centering on respiratory and mucous membrane irritation. Given its volatility, the molecule presents an inhalation risk at low concentrations, and cases of skin absorption have underlined the value of gloves. Chronic toxicity studies tend to lag, though sulfur-rich compounds occasionally show sensitization in animal tests. Regulatory agencies recommend keeping environmental release to a minimum, as thiols can disrupt aquatic organisms long before concentrations approach human hazard levels.
Future Prospects
Interest in organic sulfur chemistry hasn’t slowed. As demand grows for finer control over surface properties in electronics, energy, and biomedicine, thiols like 1-Heptanethiol will find new roles. I’ve seen hints of next-gen medical diagnostics where SAMs form the backbone of reusable biosensor chips. Nanotechnology startups look to reliable thiols to build programmable interfaces for quantum devices. Environmental groups urge development of greener, less pungent synthesis. As more industries embrace sustainability and precision, the demand for robust, well-characterized surface modifiers stands to rise. I expect 1-Heptanethiol to stay in the game, especially as green chemistry techniques refine both the source materials and downstream waste handling.
Getting to Know 1-Heptanethiol
1-Heptanethiol isn’t a household name. People working outside of specialty chemical research rarely encounter it by name. Its distinctive, pungent odor makes even small amounts memorable in any laboratory. The chain of carbon atoms and the sharp sulfur presence make it valuable in places most of us haven’t peeked. Over the years, I’ve watched colleagues handle 1-Heptanethiol at the lab bench, and the impression left is always strong—literally and figuratively.
Fuel Additives and Lubricants
First, let’s talk about its role in fuel additives and lubricants. Companies search for molecules that help engines run smoother and resist corrosion. By attaching itself to metal surfaces inside an engine, the sulfur group in 1-Heptanethiol forms a slippery layer. This helps keep friction down, which means longer life for mechanical parts and better fuel efficiency. In real-world testing, engineers see less wear on gears and cams after treating them with blends containing this compound.
Niche Uses in Electronics
Working in electronics research, there’s a constant push to build smaller, smarter sensors. In the push to miniaturize circuits, surfaces need to be functionalized—coated with very thin, controlled films. 1-Heptanethiol steps in here. It binds to gold and other metals, helping researchers grow ‘self-assembled monolayers.’ Lay terms: a single-file line of molecules sticking to a surface at the atomic level. That property lets designers tune tiny surfaces for tasks like detecting toxins in water or keeping billions of transistors communicating in a chip.
Organic Synthesis
Organic chemists know 1-Heptanethiol as a stepping stone. Its reactive sulfur group opens doors to making more complicated molecules. As a synthetic building block, chemists use it to append sulfur-capped tails to new compounds. These modifications show up in experimental pharmaceuticals or special polymers. Without reliable building blocks like heptanethiol, developing new medicines and materials would take much longer—and cost a lot more.
Challenges and Possible Solutions
Anyone who opens a bottle of 1-Heptanethiol encounters its smell instantly. There’s no disguising the stink; it clings and travels. Regular fume hoods and glove boxes become essential in spaces using even a few drops. Strong smells often bring questions about health and safety. In my time in chemistry teaching labs, proper handling and ventilation made all the difference in comfort and safety. Researchers today continue improving containment and air filtration for harsh-smelling agents like this.
Disposal brings another headache. The sulfur atom means it can linger in waste streams, so most institutions require special handling, much like lab waste with heavy metals or mercury. Investing in better neutralization and recovery tech protects both lab workers and the broader community from accidental releases.
Alternatives sometimes get considered, especially in places without top-tier fume extraction gear. Green chemistry pushes for less hazardous building blocks where possible. Designing odorless or less-volatile thiols isn’t easy, but research dollars continue to chase that goal, given the industrial and educational demand.
Final Thoughts on Its Importance
Every time I run across 1-Heptanethiol in a method or product spec, I remember the real work behind its use: balancing function, safety, and cost. In settings from fuel labs to nano-scale electronics, this compound has proved its value, even if it remains behind the scenes to those outside the bench.
Understanding the Basics
1-Heptanethiol runs under the chemical formula C7H16S. You see seven carbons, sixteen hydrogens, and a distinct sulfur grabbing attention at the end of the row. I remember the first time this formula came across my desk in the lab, and it just seemed like another long-chain thiol, but diving deeper you realize how chemicals like these pop up far beyond a classroom.
What Sets 1-Heptanethiol Apart
1-Heptanethiol has a straight carbon backbone. The "thiol" tag comes from that -SH group clinging onto the last carbon. This simple structure carries a punch for researchers and folks in industry. That sulfur bond isn't just a minor detail. Sulfur throws in a new level of reactivity, which helps during synthesis work, metal binding, even for building up surfaces at the molecular level.
During my time working with surface chemistry, I counted on molecules like 1-Heptanethiol to behave as a self-assembler. The clean, predictable line-up of carbon atoms and the reactive end make it a favorite for creating monolayers on gold. Gold sticks to that sulfur, so you end up with a field of tidy, tail-pointing molecules. This has shown up not only in research papers but real products like sensors and microelectronics.
Why Everyone Should Pay Attention
Chemicals such as 1-Heptanethiol crop up in development of new materials and coatings. One popular application, related to my own projects, deals with the creation of anti-corrosion layers. Engineers love reliable surface coverage, and 1-Heptanethiol delivers by tightly holding onto metal substrates. It helps lengthen the life of electronic parts and sensors that have to survive in nasty weather or chemical baths.
Its pungent, unmistakable odor is a headline in its own right. Short-chain thiols carry reputations for their intense scents, which sometimes get used as safety markers. For example, leaks of natural gas get detected with the help of sulfur compounds because that nose-wrinkling smell is so easy to pick out.
Risks and Precautions
Handling 1-Heptanethiol brings its own list of considerations. Like other thiols, safety glasses and gloves are non-negotiable during use. I learned quickly to never underestimate the irritation to skin and eyes, not to mention the long-lasting stench that lingers in lab coats and gloves. Beyond the aroma, volatile organic sulfur compounds like this can irritate the respiratory system. Thoughtful storage and solid ventilation systems have always been my go-to protection.
Regulators keep an eye on compounds that can escape into the air or water, and 1-Heptanethiol fits right in that category. Stricter standards for workplace exposure make sense. Increased monitoring and airtight containers lessen the chance of accidents. Investment in fume hoods and better detection methods supports both worker safety and environmental care.
Looking Forward
As research presses on, the need for versatile, reliable molecules grows. The straightforward composition of 1-Heptanethiol creates opportunities in material science, electronics, and chemical manufacturing. Green chemistry approaches nudge us toward safer alternatives for volatile thiols, yet as of now, chemicals like C7H16S earn their spot in the toolbox of future technology.
From my own hands-on experience, the key is a respect for its power and limits. Labs, manufacturers, and researchers can press ahead with safe, responsible use, pushing boundaries without losing sight of health or the environment.
What Is 1-Heptanethiol?
1-Heptanethiol shows up in labs and factories as a colorless to pale yellow liquid, carrying a very strong, sulfur-like odor. People who’ve worked in labs know that thiols always have a reputation for their smell, and this one proves no different. Common uses include its role as a building block for organic synthesis, often in small-scale research. Most people won’t find it in household items, but some industrial processes and academic research do create chances for direct exposure.
Hazards People Should Know About
Those who’ve handled or even just opened bottles of 1-Heptanethiol will recall the smell—sharp and not easy to forget. Odor aside, its chemical properties create several hazards. Contact with the skin can lead to irritation and redness. Eyes are especially sensitive to it, sometimes leading to swelling and strong discomfort. Breathing in the vapors brings another set of risks, from headaches and dizziness to throat and lung irritation.
Big concern: repeated or prolonged exposure. Actual evidence points to liver and kidney impact when animals get exposed to certain levels for a longer period. Information from Material Safety Data Sheets matches with most industrial experiences: this compound does not mix well with heat, flames, or strong oxidizers. In any place where people work with flammable chemicals, the fire risk stands out—it can ignite with the right spark or temperature. So, it carries a flammable liquid rating, making storage practices extra important.
Real-World Toxicity
The science backs up these warnings. Animal studies, regulatory guidelines, and firsthand reports fill in the story. The lethality for rodents stands higher than more common chemicals, making accidental ingestion or large spills especially serious for humans. No one should ever try to taste or purposely inhale any chemical like this, but the accidental routes—like splashes or vapors—make up most recorded cases.
No one wants to overstate the risk for someone walking past a closed, sealed bottle. Risk rises when there’s skin, eye, or vapor exposure during mixing or pouring. The type of vessel, the setup of the lab or plant, and the safety training of the people all shape how much of a hazard this becomes. Many facilities keep their own logs of near-misses and incidents, usually tied to lack of proper ventilation or hasty spills.
Limiting Exposure and Reducing Risks
My own time working in smaller industrial labs taught me not to trust even small containers with chemicals like this. Any training program worth its salt will push for goggles, gloves, and fume hoods. The best labs turn on ventilation and label storage cabinets, never hoping that employees “just know where not to look.” Regular glove changes and simple habits like checking container seals make a difference.
Reporting every near miss, every irritation, and every minor exposure helps, too. Real risk control grows from a culture where people talk about small problems before they spiral into something overwhelming. Building in double-checks—label verification, spill kits clearly visible, a phone list for emergencies—turns small headaches into learning instead of disaster.
Supporting Safer Workplaces
Organizations and research groups should keep pushing for less hazardous substitutes where possible. For projects tied to 1-Heptanethiol, sticking close to established personal protective equipment and strong ventilation systems stays non-negotiable. Regular safety reviews, open reporting, and emphasis on correct disposal will give people the tools to reduce serious mishaps. This is what turns policies on paper into safer days in the workplace.
Understanding 1-Heptanethiol
1-Heptanethiol often finds its way into research labs and chemical plants, thanks to its role in organic synthesis and surface science. The distinct, strong odor catches attention quickly, signaling the need for smart storage. I remember the first time I opened a bottle—its sharp scent lingered on my gloves. That experience taught me the importance of organization, cleanliness, and respect for chemicals that don’t just vanish into thin air.
Sensible Storage Choices
One key to safe storage sits right with the basics: segregation and containment. 1-Heptanethiol does not belong near oxidizers or acids. Any sulfur compound mixing with the wrong chemical invites risk. A well-ventilated flammables cabinet picks up some of the burden—no shortcuts around ventilation, because vapors do accumulate. I keep all “smelly organics” together, far from crowded glassware or electronics where spills become disasters.
Temperature swings mess with the stability of a lot of lab chemicals, and this one’s no different. Room temperature works, but too much heat or sunlight can build pressure inside the container. I’ve seen screw tops that bulge out from repeated temperature spikes, so always shelter these bottles away from direct light. A dry environment matters, too. Moisture can react with 1-Heptanethiol, leading to corrosive side effects most labs don’t want to confront.
Labeling and Tracking
Mistakes happen, so visible, accurate labeling matters. A clear label with full chemical name, concentration, handling notes, and hazard warnings isn’t negotiable. Black marker on white tape fades quick, but printed labels last. Beyond labels, a digital inventory helps track each bottle—what’s open, what’s sealed, what’s near its expiry date. Missed check-ins on these records once cost us a lot; a misplaced old bottle triggered a stench only closed windows and overtime could fight.
Container Choice and Integrity
Original manufacturer containers almost always suit storage best. These are designed for chemical compatibility, leak prevention, and vapor control. Glass containers with tight seals reduce the risk of leaks; plastic tends to absorb sulfides, which means lingering odor or even container degradation. I always inspect for cracks, dodgy seals, and corroded caps. Fresh containers don’t guarantee safety if the cap’s loose or the bottle cracked from a fall.
Personal Safety Measures
I learned early on that dealing with thiols without gloves, goggles, and a lab coat shortens the route to a ruined outfit or worse, a visit to the doctor. Chemical-resistant gloves (nitrile), lab coats, and good ventilation keep exposure low. Strong ventilation, whether local exhaust or a whole-room system, stops the spread of fumes. I also stash spill kits and absorbent pads nearby—there’s no telling when a small accident might require quick cleanup. No open flames, no smoking near storage, and never pipette by mouth: these aren’t just rules, they’re musts.
Regs and Routine Checks
Every region has rules on hazardous storage; OSHA and EPA have laid out clear expectations. Regular safety audits and internal inspections pay off by catching storage issues well before they develop into problems. I’ve found that consistent housekeeping and talking safety in group meetings sets an example for colleagues and keeps the entire workspace safer.
Understanding 1-Heptanethiol’s Hazards
When I started out working in the lab, it didn’t take long to spot the chemicals everyone treated with extra caution. 1-Heptanethiol stands out. This is no “ordinary” lab solvent—open a bottle and the pungent, unmistakable odor gets attention fast. That’s a warning sign. It’s not just unpleasant; the fumes can irritate your nose and throat, and skin exposure leaves a red, itchy rash.
The chemical brings flammability and toxicity to the bench. Breathing the vapors, even for a short stint, makes you feel lightheaded. Extended exposure can mess with the nervous system. Splash it in your eyes and you’re in for a painful ride. Safe handling isn’t about paranoia—it’s grounded in solid, lived experience. Every year, emergency rooms see splash injuries and overexposure from underestimated chemicals. The right habits keep those numbers down.
Personal Protection: Not Just a Lab Rule
Showing up in shorts and sandals, hoping for a quick synthesis, invites trouble. Long cotton pants cover your legs. A decent lab coat shields your arms. Nitrile gloves fit snug, keep your skin from itching or stinging later. Eye protection is non-negotiable—1-Heptanethiol stings, and once it finds its way into your eyes, flushing with water won’t make you forget the pain. If you ask around, you’ll hear stories about students who learned the hard way that regular glasses don’t cut it.
Ventilation: Fume Hoods Save Health
The day someone tried to transfer this chemical outside the hood, the smell drifted down the hall and into the classroom. Even at low concentrations, the compounds in heptanethiol hit hard. Inhaling organic thiols carries health risks well beyond temporary discomfort. A functioning fume hood keeps vapors locked away—a basic, essential step. Relying on open windows? That’s no replacement. Modern labs require fume hoods for a reason.
Handling and Storage: No Shortcuts
Containers with tight lids help limit vapor release. Labeling avoids the classic mix-up: “clear, colorless liquid #12.” Store the bottle in a cool spot, away from any flames or heat sources. I’ve seen what happens when flammable liquids fine their way too close to Bunsen burners—no one wants that mess. A flammable cabinet keeps these risks under control and meets legal codes that inspectors actually check—firsthand experience proves that failing to prepare leads to sudden headaches during audits.
Spills and First Aid: A Plan, Not Panic
If there’s a spill, most people’s first instinct is to grab paper towels. That spreads the problem. Instead, sand or commercial absorbent keeps everything localized. Dispose as hazardous waste—don’t send it down the drain, or the plumbing crew will be wearing masks next week. For soaked clothing, peel it off right away, wash fast, and alert your supervisor. Emergency eyewashes and showers should work, not collect dust.
Training and Reporting: Passing Down Knowledge
I learned the details not just from manuals, but from techs who’d seen accidents up close. Reading the SDS feels dry, but it saves lives. Training matters—everyone on the bench should know emergency numbers and spill procedures. If symptoms show up, nobody should shrug off dizziness or skin burns. Quick action, not embarrassment, leads to the best outcomes.
Safety grows from knowledge passed hand to hand. In labs and industrial settings, the way we respect hazardous materials directly shapes our health and productivity.
| Names | |
| Preferred IUPAC name | Heptane-1-thiol |
| Other names |
Heptane-1-thiol
n-Heptyl mercaptan 1-Mercaptoheptane |
| Pronunciation | /ˈhɛp.təˌθaɪ.ɒl/ |
| Identifiers | |
| CAS Number | 111-31-9 |
| 3D model (JSmol) | `/gfx/mol/3d/3dmodel/1-Heptanethiol.jmol` |
| Beilstein Reference | 1206726 |
| ChEBI | CHEBI:38161 |
| ChEMBL | CHEMBL16363 |
| ChemSpider | 81593 |
| DrugBank | DB14055 |
| ECHA InfoCard | 03d896da-021a-4a2e-a0dc-c84f23c0c22e |
| EC Number | 204-689-0 |
| Gmelin Reference | 82142 |
| KEGG | C02721 |
| MeSH | D006531 |
| PubChem CID | 8121 |
| RTECS number | MN2100000 |
| UNII | 208NIC2UHL |
| UN number | UN2347 |
| Properties | |
| Chemical formula | C7H16S |
| Molar mass | 148.29 g/mol |
| Appearance | Colorless to yellow liquid |
| Odor | unpleasant mercaptan-like |
| Density | 0.835 g/mL |
| Solubility in water | Insoluble |
| log P | 3.8 |
| Vapor pressure | 0.0474 mmHg (25°C) |
| Acidity (pKa) | 10.6 |
| Basicity (pKb) | 3.32 |
| Magnetic susceptibility (χ) | -86.0e-6 cm³/mol |
| Refractive index (nD) | 1.435 |
| Viscosity | 1.245 mPa·s (25 °C) |
| Dipole moment | 1.21 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 247.6 J⋅mol⁻¹⋅K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -41.3 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -4822.7 kJ/mol |
| Pharmacology | |
| ATC code | '' |
| Hazards | |
| GHS labelling | GHS02, GHS07, GHS08 |
| Pictograms | GHS06, GHS08, GHS09 |
| Signal word | Warning |
| Hazard statements | H226, H302, H311, H314, H331, H411 |
| Precautionary statements | P210, P233, P261, P273, P280, P302+P352, P305+P351+P338, P312, P403+P235, P501 |
| NFPA 704 (fire diamond) | 2-2-0 |
| Flash point | Flash point: 82 °C |
| Autoignition temperature | 215 °C |
| Explosive limits | Lower: 0.7%, Upper: 5.5% |
| Lethal dose or concentration | LD50 (oral, rat): 700 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral rat 810 mg/kg |
| NIOSH | SN 8750 |
| PEL (Permissible) | PEL: Not established |
| REL (Recommended) | REL: 0.5 ppm (2 mg/m³) |
| IDLH (Immediate danger) | 100 ppm |
| Related compounds | |
| Related compounds |
Methanethiol
Ethanethiol 1-Propanethiol 1-Butanethiol 1-Pentanethiol 1-Hexanethiol 1-Octanethiol |
