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Chemists traced the earliest synthesis of 1,10-phenanthroline, or fenantrolina, back to the late 1800s. Interest snowballed mid-20th century, when teams in both Europe and North America recognized how the ligand locked onto metal ions in coordination chemistry. The classic Werner complexes, a mainstay of college chemistry labs, owe some of their visual appeal to this compound. Long after, this molecule keeps earning new fans, not out of nostalgia, but from its resilience in research and industry.
Fenantrolina boils down to a nitrogen-rich aromatic heterocycle, formula C12H8N2. A yellowish powder at room temperature, it dissolves in ethanol, chloroform, and aqueous acid. Buy a bottle and you'll spot labeling that covers both its trade and systematic names. Suppliers target both research and manufacturing markets. Academic labs use it straight from the jar for titrations or as a building block, while pharmaceutical or material science outfits demand higher purity, usually above 99%.
This molecule stays solid with a melting point around 117°C, resists oxidation, and tends to produce vivid colors in ion complexes. Chemists value its chelating grip on transition metals, forming rigid, stable complexes. I have used it in spectrophotometric iron assays, and the orange-red color the Fe(II)-phenanthroline complex produces makes analysis straightforward. Its planar structure and aromaticity allow π–π stacking, something material scientists exploit.
Labels for 1,10-phenanthroline often show the empirical formula, molecular weight of about 180.21 g/mol, and a warning about its skin and eye irritant potential. Material Safety Data Sheets deliver further details. Pure forms pack tight in opaque bottles, capped in inert atmospheres. Manufacturers pride themselves on batch analysis sheets certifying metal content at parts-per-million levels, reminding buyers that minor impurities can trip up sensitive catalytic or biological studies.
In most labs, preparation of fenantrolina traces back to the Skraup-style synthesis. The reaction fuses o-phenylenediamine with glycerol and an oxidizing agent—traditionally ferric sulfate—under acid. I remember fumbling my first batch as a graduate student, realizing too late how exothermic the process runs. Vigilance pays off, since careful heating and controlled addition of reactants combat side products and maximize yield. Commercial producers now favor safer, greener oxidants and recycle mother liquors to recover unreacted starting material, pushing sustainability.
The two nitrogen atoms at the 1 and 10 positions mean this molecule chelates metals like copper, iron, and nickel with a vengeance. Subtle tweaks at the ring periphery—methyl, nitro, or carboxyl substitutions—change binding strength and selectivity. I’ve seen research that attaches bulky groups to improve solubility in water, making custom complexes for biological applications. These modifications feed into catalytic processes, analytical assays, and even DNA intercalation studies. Anyone working with transition metal catalysis has likely handled a derivative of phenanthroline, recognizing how the structure directs electron flow and stabilizes active sites.
Buyers may encounter trade names like “Phen,” “O-Phenanthroline,” or “1,10-Phen,” along with more technical entries in catalogs. ECHA and IUPAC stick with 1,10-phenanthroline as the preferred name. Synonyms clutter some older journals, but most researchers now keep to the concise forms. Knowing which alias matches your supplier’s certificate avoids confusion, especially when regulatory paperwork comes due.
Laboratories train staff to avoid direct contact, since powders splashed on skin or eyes cause irritation. Dust inhalation should be avoided. Work in a fume hood, wear safety glasses, gloves, and a lab coat. Standard operating procedures cover wet disposal, as the compound persists in the environment. Accidents seem less common with this compound than with other organic reagents, but diligence means handling even well-known molecules with respect. The chemical industry uses closed systems for transfer, and scales up under constant monitoring, to minimize both exposures and environmental releases.
Classic uses pop up in analytical chemistry, such as ferrous iron determination—a staple of water quality assessment. Research groups design phenanthroline complexes as enzyme mimics, molecular sensors, and light-responsive materials. In catalysis, especially C–H activation, phenanthroline ligands steer reactions by controlling metal geometry, a detail chemists love to debate. DNA-binding studies use the compound as an intercalator, poking at mechanisms behind anticancer agents. Its range keeps expanding, and each time a new technique debuts, phenanthroline usually finds a role as a probe, ligand, or structural template.
Teams race to modify the core skeleton, seeking water solubility, redox activity, and selectivity for unusual metal ions. Work in fluorescence sensing draws from phenanthroline’s electronic structure, building diagnostic kits for medical and industrial testing. Green chemistry aims to replace legacy solvents and oxidants, reducing cost and environmental impact. Collaborative networks keep this molecule in play across continents—whether the lab focuses on alternative energy or molecular imaging.
Animal testing indicates moderate acute toxicity, but regulatory bodies have not flagged phenanthroline as a major hazard under normal use. Chronic data hold gaps, especially regarding aquatic toxicity, so waste streams need careful treatment. In vitro data reveal enzyme inhibition at higher doses. I have seen researchers stress quick clean-up of spills, not just from personal safety, but to avoid bioaccumulation concerns. As new applications develop, especially in medicine, more granular studies around metabolites and long-term exposure will decide whether its use needs tighter controls.
Discovery keeps circling back to old molecules, and phenanthroline stands as proof. Its core appeals to those designing next-generation catalysts and electronic materials, because its reactivity and stability set a strong foundation. Researchers tinker with hybrid ligands built around this backbone, chasing better renewable energy storage, sensors, and green synthetic methods. More regulatory attention may push for biodegradable analogues or closed-loop manufacturing systems. I’ve watched young chemists pick up classic ligands and find unexpected applications in biotechnology and quantum materials. The story of phenanthroline looks far from finished, especially for anyone who believes creative chemistry matters.
1,10-Phenanthroline—often called “phen” by chemists—has one of those names that can scare off non-specialists. Underneath the chemistry jargon, this compound serves as a real workhorse in analytical labs. Anyone who has ever fiddled with test tubes as part of research probably knows it well, though maybe not by its full name.
If you ask a seasoned lab tech or a chemistry professor about “phen,” their minds will go straight to its action as a ligand. In plain terms, this means phen locks onto metal ions and forms stable complexes. The big standout job centers on iron, especially iron(II). Phen teams up with iron(II) to make a complex that gives a deep red color. Chemists rely on this trick for detecting and measuring trace amounts of iron in water, soil, food, or even blood. Spectrophotometry—a standard method—uses this color change as an easy, clear reading.
Anyone who has worked in environmental science, agriculture, food safety, or healthcare research has felt the convenience of this method. No need for expensive instruments at every step; the red color alone often tells the tale. Doctors and engineers alike have trust in results drawn from this simple color change, because the complex between phen and iron(II) proves stable and reliable. In labs I’ve worked with, phen still ranks as the go-to way to check for iron, especially in field kits for water testing.
Chemists haven’t stopped at iron. Phenanthroline forms complexes with copper, nickel, and other metals. Researchers have explored it for detecting copper in biological samples, which matters for nutritionists, physicians, and people keeping an eye on heavy metals in the environment. Lab teams turn to phen to separate metals and study reactions that underpin new materials or medicines. The ease with which it forms complexes makes it a favorite in teaching, too. I have seen dozens of undergrads run phen tests during their chemistry lab courses, providing one of those rare “wow” moments for students who believe chemistry mostly exists inside textbooks.
Take a walk through a synthetic chemistry department, and phen shows up again as a ligand supporting catalysts. Chemists studying reactions that build complicated molecules—pharmaceuticals, new materials—use it to speed up or steer reactions toward the right result. Certain batteries and solar cells also draw upon phen’s ability to tie up metal ions and keep reactions humming along cleanly. Chemists rely on its consistency. The reproducibility of phen-based systems keeps research and production lines going without needless troubleshooting.
A push exists for chemistry that leaves less mess—in terms of waste and toxicity. Phen itself brings some environmental challenges, since it doesn’t break down easily and can stick around in the environment. Green chemistry advocates urge mindful disposal and look for biodegradable analogs. Proper lab protocols, careful disposal, and ongoing education make a real difference; I’ve seen schools switch over to safer practices with just a day’s training. The widespread use of phen has spurred this evolution within the chemistry community.
Our world leans ever more on clear, simple ways to analyze materials—whether for health, industry, or environmental safety. Phen proves that a century-old molecule can stay vital, tying advanced research and practical needs together. Its color test for iron remains one of those rare tools that stretch across student projects, industrial labs, and government inspections—serving as a quiet backbone of modern analytical chemistry.
Fenantrolina—known to many chemists as 1,10-Phenanthroline—gets plenty of use in chemical analysis. You find it acting as a ligand, forming complexes with metal ions, often popping up in redox titrations, and its orange-red iron(II) complex looks pretty striking in the beaker. I’ve seen university students discover its strong complexing powers in coordination chemistry labs. That punchy color shift when iron comes in contact makes it a favorite for demonstrating chemical concepts, but it’s not something to treat lightly.
People handle chemicals with varying degrees of confidence, from new students to career lab workers. With fenantrolina, the white crystal powder doesn’t seem intimidating at first glance. Still, it’s not just a benign tool. There isn’t a huge amount of public experience with it outside academic or specialized analytical labs, but toxicology data does give reason to pause.
Published safety sheets tell that fenantrolina irritates the eyes, skin, and mucous membranes. Inhaling dust or vapors can cause respiratory discomfort, and swallowing even a small amount can result in stomach upset or headache. Some animal studies show signs of more serious effects at higher doses—liver and kidney concerns stand out. The risk of severe poisoning in a typical lab setting remains low, but the molecule gets taken seriously in professional laboratories.
Sticking with basics pays off. Don’t touch the stuff directly—nitrile gloves keep skin protected during weighing and mixing. Working in a well-ventilated area or fume hood helps, especially considering the irritation risk. I remember accidental spills during rushed preparation sessions; quick cleanup with wiped surfaces and cold water seems simple, but complacency can cost you your comfort or safety.
Most labs storing fenantrolina keep it away from acids and oxidizers, following established protocol. Eyes take the brunt of many lab accidents, so goggles always find their place during use. If dust happens, prompt rinsing and attention to symptoms is important. Dry powders drift remarkably easily, and vacuuming with suitable filters beats sweeping.
Many incidents come from underestimating “ordinary” chemicals. Training and supervision can limit these missteps. I’ve seen lab instructors drill the habit of checking safety sheets and logging use, even for routine chemicals. These practices build respect for materials and boost confidence. Safety culture grows not just from fear, but through repetition, shared knowledge, and a willingness to admit uncertainty.
Universities and companies increasingly invest in clear labeling and point-of-use instructions, making it harder for users to ignore risks. Color-coded storage and digital inventory logs help reduce mix-ups. Encouraging people to ask for help, rather than bluff through uncertainty, sets the tone for responsible handling. Everyone deserves a lab where they can focus on discovery without hidden hazards haunting the process.
Fenantrolina plays a central part in analytical and coordination chemistry, and the benefits far outweigh minor safety hurdles in a well-run lab. Habitual good practice, reliable safety equipment, and real engagement with chemical knowledge all lead to healthier outcomes. By being realistic about hazards and using available resources, anyone working with this compound can keep their focus where it belongs—on the experiment at hand.
1,10-Phenanthroline, known in labs as C12H8N2, pops up often in chemistry textbooks and research articles. It’s recognizable by its rigid, flat structure—two rings fused together and a pair of nitrogen atoms in just the right places. These nitrogen atoms make it a handy chelating agent. Metal ions tend to stick to it, making this molecule a reliable choice for complex formation in various experiments.
The molecule brings with it a stubborn streak. Drop it into water and it won’t just dissolve smoothly like sugar in tea. 1,10-Phenanthroline’s solubility sits at about 0.6 g/L at room temperature. The reason traces back to its molecular makeup. That flat, aromatic system doesn’t care much for hydrogen bonding, which water relies on to welcome new molecules. Its nitrogen atoms draw in some polar character, but the rest stays stubbornly nonpolar. Compare that with salts or simple alcohols and you see why this powder often sinks to the bottom of a beaker before it shows signs of mixing in.
I’ve handled phenanthroline plenty in the lab. We always hit the same snag: the stubborn chunks that refuse to budge in solution. Heating and vigorous stirring help. Sometimes you just need patience and a water bath, coaxing those last bits to surrender. Folks in research often turn to ethanol or methanol instead. With these, 1,10-phenanthroline easily blends. Lab protocols usually call for a small stock made in ethanol and then careful dilution into water. It’s a neat workaround that many chemists learn after spending an hour scratching a glass rod at the bottom of a beaker.
So why does anyone bother with water at all? Toxicity and reactivity play big roles. Ethanol or methanol brings flammability and health risks, especially when scaling up preparations or working with sensitive biological assays. Water wins on safety and cost, so chemists keep trying to get more out of it, even with finicky molecules like 1,10-phenanthroline.
Researchers have played with several tricks for handling poor solubility. Adjusting the pH can help, since phenanthroline can pick up protons under acidic conditions. A more acidic environment adds to its solubility, but only up to a point; past that, degradation threatens. Gentle warming, stronger stirring, or ultrasonic baths sometimes force a little more powder into solution without risking its chemical integrity.
Solid data helps keep expectations realistic: don’t expect miracles in pure water. Mixing in a cosolvent like ethanol remains one of the most reliable approaches if chemical compatibility lines up. Some techs opt for ready-to-use premade phenanthroline solutions in ethanol, then add a bit of water just before use. This practice isn’t just about convenience. It sidesteps the frustration of undissolved leftovers and reduces waste from failed attempts.
The practical demands of research set a pace that doesn’t let lab workers spend hours fussing with stubborn powders. Reliable protocols matter more than wishful thinking. For 1,10-phenanthroline, knowing and respecting its water solubility shapes how it gets used across chemistry and biology. It’s one of those stubborn realities chemists accept, finding solutions with the resources and safety goals at hand, always aiming for good science without wasted time or material.
In a busy lab, the right storage practices can draw a sharp line between reliable results and a shelf full of compromised reagents. Fenantrolina, known by its chemical formula C12H8N2, rarely causes a stir—until moisture creeps in or sunlight hits a bottle. Experience repeatedly teaches that once a compound like this goes off, purity checks become a headache and experimental data starts getting weird. Lab budgets get tight, and no one’s thrilled to throw out a batch that once cost real money because of a leaky cap or sunbeam. Reliable storage does more than protect investments; it shields everyone from unnecessary risk.
Fenantrolina powder looks resilient, but air and water work on it quietly. Left on a crowded shelf with exposure to regular room humidity, it chalks up, clumps, or even changes color. Such changes creep up, only drawing attention when solutions cloud up, analytical readings drift, or a synthesis won’t go to completion. I’ve witnessed the frustration of wasted afternoons, searching for the mistake, only to realize moisture crept into a reagent jar.
Fenantrolina often attracts attention in coordination chemistry, especially as a ligand in catalysis and metal ion detection. These applications count on purity. Impurities, especially from breakdown products caused by bad storage, undercut repeatable results. Funding agencies don’t want explanations about poor controls. Researchers need confidence that their data reflects real phenomena, not trouble from a dusty shelf.
Storing this compound starts with shielding it from damp air and sunlight. Tightly sealed, amber-colored glass bottles make a difference. I’ve seen labs use clear glass containers or loose plastic caps, only to regret shortcuts during annual inventory. Amber bottles block out UV light, which slows decomposition. Screw caps with PTFE liners keep out humidity and air. An added silica gel pack inside the cabinet adds another layer of protection, capturing stray moisture.
Temperature matters, too. With fenantrolina stable at room temperature, avoid wide swings—no hot radiators nearby, no freezing and thawing cycles. Refrigerators help in tropical environments, as long as humidity doesn’t condense inside the vial during access. If refrigeration isn’t available or necessary, a dry, consistently cool storage room works just as well when humidity stays low.
Labeling jars with the opening date isn’t common everywhere, but it’s saved me confusion more than once. If a bottle’s been sitting for more than a year, I test it before using it for any precise work. A quick look for color shifts or clumping, a re-weigh before every calculation—these small steps cut back on mistaken results and complaints about reagent inconsistencies.
Some labs create a checklist for proper chemical storage, making new students or staff accountable early on. Shared spaces—where people from different projects dip into each other’s chemicals—benefit from this communal approach. Training everyone to return bottles tightly capped to the right spot turns a tedious task into a habit. I've seen dramatic drops in chemical waste costs just by building a culture around vigilance. Risk minimization isn’t a bureaucratic nightmare; it’s basic respect for everyone’s time and effort.
When storage slips, the whole chain of chemical work suffers. Enough mishaps have shown it often takes only one contaminated batch to ruin a week or more of experiments. By locking down simple habits—dry, dark cabinet; tight lids; clear labeling—labs give themselves a leg up. Public funding and scientific progress both lean on reliable methods, and proper fenantrolina storage forms part of that foundation.
Many people know 1,10-phenanthroline—the compound commonly referred to as fenantrolina—for its role as a ligand in coordination chemistry. With its catchy formula, C12H8N2, this molecule draws a lot of attention in labs and classrooms. Scientists value it not just for its bright orange-red iron complexes, but also for the lessons it gives about chelation, spectroscopy, and analytical chemistry. Dive beneath the surface a bit, and questions about molecular weight pop up fast.
It doesn’t take a PhD to remember the steps. To find fenantrolina’s molecular weight, count up the mass from each atom. Carbon clocks in at about 12.01 grams per mole, hydrogen adds 1.008, and nitrogen brings 14.01. Pull out a calculator or grab some scratch paper, and the math rolls out:
Add those up, and you’re staring at a sum of roughly 180.20 g/mol. For chemists, this number drives everything: solution prepping, reagent mixing, and data reporting. Mess it up, and results tumble out of line. People learn soon enough that accurate molecular weights aren’t just technical details—they make or break experiments.
In teaching undergraduates, I’ve watched bright students fumble titrations or get skewed absorption readings from a bad mass calculation. This isn’t just nitpicking; a splash of error in the math quickly turns into wasted time, missed deadlines, and extra lab expenses. A molecule’s weight proves itself every day in the field. While some overlook these calculations, research lives by reliability. Chemical supply companies list molecular weights for good reason—not just tradition, but to keep buyers and scientists on steady ground.
Move outside the classroom, and 1,10-phenanthroline steps up as an analytical star for detecting ferrous iron. Drop it in a test tube with Fe2+, and the solution turns orange-red—clear proof in environmental testing or pharmaceutical analysis. Any result trusted by industry hinges on dead-on math right from the start. Iron content in water, blood, or soil doesn’t leave room for rounding errors.
High quality research takes effort and habits that don’t cut corners. Labeling chemicals with correct masses, double-checking calculations, and using calibrated balances set up a path for better data. Mistakes in the basics ripple into bigger headaches. Teaching careful habits early builds confidence in scientific results, saves money from repeating experiments, and builds trust in published data. Chemical accuracy, like good recipes, comes down to respecting the details.
Resources for checking these numbers sit everywhere: CRC handbooks, supplier datasheets, and digital calculators. Stepping into a science workspace, confidence grows when everyone agrees on the same math and methods. Taking an extra minute to check a molecular weight can save hours—sometimes weeks—of troubleshooting. Reliable data sets the stage for new discoveries, new medicines, clean water, and honest answers. It all starts with keeping the numbers straight.
| Names | |
| Preferred IUPAC name | 1,10-phenanthroline |
| Other names |
1,10-Phenanthroline Orthophenanthroline o-Phenanthroline 1,10-Phenanthroline monohydrate |
| Pronunciation | /fəˌnæn.trəˈliː.nə/ |
| Identifiers | |
| CAS Number | 66-71-7 |
| Beilstein Reference | 109918 |
| ChEBI | CHEBI:36355 |
| ChEMBL | CHEMBL1448 |
| ChemSpider | 8957 |
| DrugBank | DB11353 |
| ECHA InfoCard | 100.021.605 |
| EC Number | 201-007-4 |
| Gmelin Reference | 85787 |
| KEGG | C00581 |
| MeSH | D003996 |
| PubChem CID | 3237 |
| RTECS number | SF7873000 |
| UNII | 9U1VM840SP |
| UN number | Not regulated |
| Properties | |
| Chemical formula | C12H8N2 |
| Molar mass | 198.21 g/mol |
| Appearance | white crystalline powder |
| Odor | Odorless |
| Density | 1.211 g/cm³ |
| Solubility in water | slightly soluble |
| log P | 1.86 |
| Vapor pressure | Negligible |
| Acidity (pKa) | 4.86 |
| Basicity (pKb) | 4.88 |
| Magnetic susceptibility (χ) | -0.74×10⁻⁶ |
| Refractive index (nD) | 1.658 |
| Dipole moment | 3.09 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 171.0 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | 38.56 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -5335 kJ·mol⁻¹ |
| Pharmacology | |
| ATC code | S01XA04 |
| Hazards | |
| Main hazards | Harmful if swallowed. Causes serious eye irritation. Causes skin irritation. Toxic to aquatic life. |
| GHS labelling | GHS07, GHS09 |
| Pictograms | GHS07 |
| Signal word | Warning |
| Hazard statements | H302 + H312 + H332: Harmful if swallowed, in contact with skin or if inhaled. |
| Precautionary statements | P261, P264, P270, P271, P301+P312, P304+P340, P312, P330, P403+P233, P405, P501 |
| Flash point | > 204.3°C |
| Autoignition temperature | > 570°C |
| Lethal dose or concentration | LD50 oral rat: 1320 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral, rat: 1320 mg/kg |
| NIOSH | SR3325000 |
| PEL (Permissible) | Not established |
| REL (Recommended) | 6毫克每立方米 |
| IDLH (Immediate danger) | Not listed |
| Related compounds | |
| Related compounds |
Phenazine Quinoline Diquat Bathophenanthroline Neocuproine |
