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For years, the pursuit of stable, functional, and efficient ligands in the world of coordination chemistry has led scientists to tinker with more than just simple cyclodextrins or crown ethers. Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane—better known to many in the lab as Kryptofix 222—tells the story of ingenuity sparked by the need for precision. The molecule first gained traction in the 1960s, a time when researchers were chasing after compounds capable of trapping specific metal ions, hoping to advance fields ranging from catalysis to medical imaging. I remember flipping through brittle chemistry journals in grad school, seeing excited notes about its uncanny knack for binding potassium ions tightly. The buzz stretched far outside its immediate discipline, showing up in textbook case studies that drew bright lines from basic science to real-world applications. From its origins, Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane has carried the reputation of a molecule that turned theory into practice by solving problems others hadn’t realized existed.
People in chemistry circles speak about Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane with a kind of grudging respect. Known for its cage-like structure full of oxygen and nitrogen atoms, this molecule has a way of wrapping around certain metal ions—especially potassium—making it almost indispensable in the selective extraction of these ions from challenging mixtures. Researchers looking to tweak selectivity or push separations past stubborn boundaries often reach for this molecule, finding that it brings control to systems where blunt tools used to fail. It’s used in everything from organic synthesis to the world of radiopharmaceuticals, where reliable ion capture is crucial. Over the past few decades, its role has shifted from exotic lab curiosity to respected staple, bridging gaps between chemical theory, industrial application, and medical progress.
Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane doesn’t make a flashy entrance; it’s usually found as a white crystalline solid. What matters isn’t flash, though; it’s function. Its high solubility in polar solvents lets it blend into many organic and aqueous systems, broadening its utility. At the molecular level, its preorganized ring structure delivers exceptional selectivity. The arrangement of six oxygen and two nitrogen atoms provides a tailored environment for potassium and, to a lesser but still important degree, other cations such as sodium or cesium. I always marveled at the way it could ignore almost everything but the one ion you wanted captured. Stability is another plus—this molecule doesn’t fall apart in a hurry, and its breakdown products are relatively benign under most locker-room lab conditions.
Translating a clever molecule into reliable lab work takes careful labeling and specs. Chemists expect plain talk: purity thresholds, water content, clear information about counterions or solvent residues. For Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane, most bottles come with purity over 98%. That’s a simple number, but a crucial one. Even tiny impurities can throw off selectivity. Good labeling also points to proper storage—dry, away from strong acids, and safely sealed—critical for anyone who’s watched hygroscopic compounds clump or degrade overnight. The labeling, ideally, warns against casual skin contact and highlights its role, not as a bulk reagent, but as a precision instrument: treat it right, and it delivers on its promise.
Making Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane isn’t exactly a plug-and-play experiment, at least in the old-school way. The classic approach calls for a two-step process: forming a suitable precursor by reacting diethylene glycol ditosylate with triethylenediamine, then closing the ring with something like sodium carbonate. The cyclization doesn’t just happen by itself—the timing, temperature, and solvents all make or break the yield. I’ve seen students despair as their first batch gives tar or low recoveries, only to later beam when a few tweaks bring better purity. It’s still more common for people to buy it off the shelf than wrestle with the synthesis, but knowing how it’s made anchors respect for the skill that goes into every gram.
This molecule earns its stripes as a versatile tool in chemical manipulation. Its ability to form complexes with alkali metals enables dozens of downstream reactions in organic synthesis, many of which would stall or misfire without its presence. By locking on to a potassium ion, for instance, Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane can make once-insoluble salts behave in organic solvents, opening doors to new chemistries. Modification possibilities are extensive, too. Tacking different functional groups onto the core skeleton fine-tunes selectivity or solubility—a trick that’s saved several projects of mine where standard protocols wouldn’t budge. The molecule holds up to gentle oxidations and can act as a bridge for attaching more elaborate structures, much appreciated in research settings where novel chelators might push the boundaries of imaging or purification.
A mouthful like Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane rarely gets used in daily conversation. Around the lab, folks just call it Kryptofix 222. It turns up under names like 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane, and if you’re browsing catalogs, expect to find a cluster of similar codes or shorthand references. In the end, the identity doesn’t hide behind branding—the purpose stays clear, no matter the label on the bottle or the heading in the protocol.
The jump from interesting molecule to daily tool brings responsibility. Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane, for all its cleverness, doesn’t belong in careless hands. Prolonged skin exposure can cause irritation, and the compound shouldn’t wind up in drains or open air. Labs handling the substance rely on gloves, goggles, and decent ventilation. Spill protocols aren’t a joke, especially where concentration matters. Safety data underscores environmental awareness, stressing the disposal of waste through proper channels and discouraging shortcuts. These aren’t just bureaucratic rules—they reflect a culture built on minimizing harm, both in the lab and beyond.
Its signature application crops up in phase transfer catalysis—a space where separating metal ions from tangled mixtures becomes an everyday battle. In radiochemistry, Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane enables the clean separation of radiopotassium from other isotopes or trace metals, making it a linchpin for medical isotope production and diagnostics. Its use carries over to analytical chemistry, where selective binding allows for precise measurement in solutions crowded with potential interferences. I’ve seen its power firsthand in organic synthesis, where reactions that once struggled with sluggish rates or low yields came alive in its presence, changed by the magic of getting ions to behave. The molecule underpins experiments less publicized but deeply impactful, from studying ion transport in membranes to troubleshooting stubborn separations in industrial scale-ups.
Research around Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane doesn’t slow, even as its classic uses mature. Scientists push for greener syntheses to cut down on byproducts and unnecessary steps. Others chase modifications in the base structure, looking for new selectivities—cesium, lithium, maybe even transition metals. A major interest rises around the use of this molecule in sustainable separation technologies, where precision is demanded, and waste must be accountable. Drug delivery and environmental cleanup join the mix, too, as researchers adapt the molecule’s tight grip for applications outside the well-charted petri dish. The field finds energy in cross-pollination, and every year brings new methods using variants or cousins of Kryptofix to wrangle ions where nature alone won’t help. Investment in scalable, safe, and cost-effective production methods remains a top priority for broader deployment and more responsible chemistry.
The question of toxicity lingers at the edges of every high-performing molecule. Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane generally shows low acute toxicity, at least in the ways it’s been studied so far. Chronic exposure, especially through skin or inhalation, raises more subtle concerns, but responsible handling practices form a shield against most risk. Ongoing research looks at biodegradation and persistence, a field pushed by growing regulation and public scrutiny around chemical persistence in wastewater. Sustainable use leans hard on real toxicity data, not assumptions or wishful thinking. Regulatory compliance, including clear documentation about potential hazards, means nobody can plead ignorance when working with this tool. The molecule’s generally good safety profile reflects decades of careful oversight, more than luck or accident.
Modern chemistry moves on the blend between established molecules and new applications. Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane sits squarely at that intersection. Its selectivity and stability grant it a spot in any toolkit focused on ion management, whether that’s in batteries, recycling metals, or next-generation diagnostics. Pushes for more sustainable and biodegradable alternatives have started to shape its development pipeline, but its proven reliability keeps it in circulation. Researchers are likely to build on its template, seeking molecules with improved environmental footprints or extended selectivity. I picture a future where its descendants appear in more places: medical imaging, clean energy, waste stream remediation, and sophisticated analytical sensors. The simple, cage-like structure born from an era of curiosity now functions as a bridge to what’s next, grounding innovation in a legacy forged by need and honed by experience.
Some chemicals fly under the radar, even though scientists use them almost every day. 4713162124 Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane belongs to this club. It doesn’t roll off the tongue and rarely makes headlines. Still, this cage-like molecule, better known as Kryptofix 222, does some heavy lifting in the world of analytical and synthetic chemistry. Anyone who spends time in a lab working with ions or radioactive elements comes across it sooner or later.
The main thing that sets this compound apart: its knack for wrapping up metal ions. Picture a molecular basket that grabs a potassium ion or a similar cation and locks it away from the rest of a mixture. That’s what Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane does. Its size and nitrogen-oxygen structure help it form tight complexes with metal ions, especially potassium and sometimes sodium. This makes it possible to separate those ions from other ingredients in a chemical soup.
If you deal with radioactive isotopes in nuclear medicine, you notice how essential clean separations have become. Most of the time, you find high-purity compounds by using selective binding like this. Many radiochemists use this molecule to isolate and concentrate radioactive potassium or cesium isotopes, which ensures accurate results in tracing studies or when preparing doses for diagnostic procedures.
Synthetic chemists often run into situations where a salt, such as potassium carbonate, just won’t dissolve in organic solvents. Working with Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane, you can bypass this roadblock. It grabs potassium ions and allows salts to break up in non-water-based liquids. That opens the door for all sorts of new reactions, including tough alkylation or nucleophilic substitutions with stubborn substrates.
I remember running a reaction that absolutely needed potassium ions, but my solution stayed cloudy no matter how hard I stirred it. Adding a pinch of this compound, the whole vial cleared up and the product yield jumped. It’s a small fix that saves hours in the lab and makes new discoveries possible.
Analytical labs lean on Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane to tidy up samples before testing them. Messy samples mean unreliable results. In mass spectrometry, for example, salts can clog systems or interfere with readings. By trapping the right ions, analysts keep backgrounds clean. This translates to fewer false positives or negatives—a major deal for drug testing labs, food safety investigators, and forensic scientists. If the data speaks for itself, people trust the process more, and that’s how reputations are built.
Some folks worry about the impact of these complexing agents once they enter the environment. Chemists now work on lighter footprints by developing new methods that recover and recycle these molecules, or by designing similar compounds that break down harmlessly. Industry and academia start to share protocols that clean solvents and reuse chemicals. Change comes slowly, but the push for safer labs and green chemistry is unmistakable. Better tools, such as reliable sequestrants like Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane, help drive the progress.
References:No matter how long someone has worked with chemicals, that sense of caution should never fade. I’ve found the best defense starts with reliable gloves and safety goggles. Nitrile gloves give solid protection for a range of acids and bases. Splash-resistant goggles keep those eyes safe—even one stray drop turns a regular shift into an emergency. In my first lab job, an old-timer pulled me aside: “Don’t trust your hands or eyes to memory.” He was right. Even quick tasks deserve proper gear.
Labels give some clues, sure, but the real information sits in the Safety Data Sheet. Years back, I saw a group skip the sheet and pay for it—what looked like a harmless powder produced toxic fumes when mixed with another cleaning agent. Severe headaches sent two people home. I still remind my team to actually read the hazards section, not just toss the bottles in a storeroom. It’s not paranoia. It’s preparation.
Fresh air chases danger out of the room before it hangs around in our lungs. Most folks picture a fume hood and think that’s enough. I learned the hard way, during a poorly ventilated experiment, that some vapors sneak up and cause dizziness or worse long before you can see the cloud. Keep extraction fans clean. Never block the sash. From personal experience, hoods only protect as well as the care you take with every connection and clamp.
Companies invest in spill kits, yet I’ve watched too many people freeze up or grab the wrong gear. I once panicked at the sight of acid on a countertop, even knowing where the kit was stored. Now, I push for annual spill drills. Practicing with neutralizer and proper disposal containers turns instinct into muscle memory. When real trouble hits, folks move with purpose, not confusion.
A rushed coworker once removed a bottle cap with a penknife instead of the right tool. Splashed his sleeves, ruined his watch, and nearly trashed a whole morning. It all comes down to discipline. No food or drink in the workspace—ever. Clean up small leaks right away. Never pour chemicals down random sinks. In one shop, someone dumped corrosive waste into an open drain, causing a pipe to burst and billow out fumes. That one mistake cost the business a week of repairs and a hefty fine.
Safety isn’t just a checklist—it's a routine built into the work culture. Regular refreshers matter. Supervisors should model good behavior, not cut corners for convenience. I keep a copy of the chemical inventory within arm’s reach, not buried in an office. We go through storage cabinets twice a year, hunting expired stock before it surprises us. This approach doesn’t slow down productivity—it protects people.
In my experience, the most effective way to manage risk is by sharing stories of near misses as much as official training. Bringing in experts for updates helps everyone stay alert to new research or improved equipment. Open communication about mistakes can feel uncomfortable, but it leads to better habits. Investing in clear labelling, easy-to-access wash stations, and ongoing drills creates long-term safety. People remember the lessons longer if they play an active role in them.
I’ve seen too many people treat chemical storage like an afterthought. There’s a locked cabinet, or a shelf in a corner, or a cool basement, and that’s supposed to suffice. But the reality paints a different story. Small mistakes pile up—an unexpected reaction here, a mislabeled drum there, a spill in a space not built for containment. These issues can threaten not only research projects or manufacturing processes, but also the health of everybody in that building.
Storing a compound isn’t a box-checking exercise. Each substance has its quirks. You can’t lump an oxidizer in with organic solvents and forget about it. Chemicals degrade if exposed to moisture, air, light, or the wrong temperature. I’ve watched a basic bottle of phenol turn into an unusable mess from a week on a warm, sunny shelf. Some powders draw so much water from the air they dissolve themselves before you’re ready to use them.
Many workplaces rely on standard operating procedures and hope their chemical hygiene plan covers every scenario. But real control comes with knowing the actual risks those bottles and bags carry. Take lithium aluminum hydride: even a trace of moisture sets off a reaction, releasing hydrogen. Unless you’ve seen a lab scramble to vent a swelling cap, it’s hard to grasp just how quickly things can spiral.
History remembers disasters like the Texas City Explosion or smaller-scale fires in academic labs not because of complicated science, but simple things—a cart left in the wrong spot, a container with a loose seal. These events underline the point: correct storage is non-negotiable.
Laws and guidelines exist, but compliance is just a baseline. The Globally Harmonized System and OSHA guidelines tell you whether something counts as “flammable,” “corrosive,” or “toxic.” The Safety Data Sheet delivers technical details. But translating that document’s numbers into real-world action takes some thought. If the sheet says “store at 2°C to 8°C,” you can’t toss the bottle in the regular fridge with yesterday’s lunch, risking a cross-contamination or unintended vapors.
There’s more to it. If the SDS warns about strong oxidizers or incompatible acids, that’s a concrete directive—these shouldn’t ever touch, not even if someone’s in a rush. I’ve talked with researchers who thought a plastic-lined bin would handle everything. Turns out, some compounds chew through plastic like tissue paper, and then there’s a pool on the floor.
Knowledge is only half the battle. Storage only works if people respect the risks. Mark shelves by hazard, not by project name. Rotate stock so older containers get used first. Never store above eye level. It may sound like old advice, but it works. Trust between colleagues grows when everyone feels protected, not because a form says so, but because everyone acts as if it matters.
Technology offers some help. Environmental monitoring with alarms for temperature swings or humidity alerts can catch problems before they escalate. Automated inventory tracking makes sure nothing sits forgotten past its expiration. But machines can’t replace clear labeling, careful segregation by hazard class, and a willingness to ask questions when unsure.
Nothing beats a culture where people look out for each other and the materials they handle daily. One person’s shortcut with storage can endanger an entire facility. It’s always worth taking a moment—open the SDS, read more than the summary, talk to others who’ve handled it before. The consequences of overlooking proper storage are too costly to ignore.
Chemistry sometimes feels a bit mysterious, especially when a compound carries a name like Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane. This name, though, gives us valuable clues. By reading through each part, the language of chemistry starts to look like a puzzle—a puzzle that reveals how atoms connect and what sort of labyrinth they build together.
So what is this molecule, really? In day-to-day laboratory work, chemists refer to it as Kryptofix 222. This is a crown ether, part of a wider family of compounds famous for their knack for trapping metal ions right in their center. At its core, this molecule wraps around positively charged ions, especially potassium, in a kind of cage—hence the “bicyclo” and “hexacosane” in the name. That’s not just a party trick. This knack for capturing ions opened up huge opportunities for chemistry labs in the 1970s, including more accurate separations and new pathways for chemical synthesis.
Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane features a ring made from alternating oxygen and ethylene groups, tied together by two nitrogen atoms. The name tells us the story: “hexaoxa”—six oxygen atoms; “diaza”—two nitrogen atoms; “bicyclo[8.8.8]”—a cage-like structure with three arms, each containing eight atoms. Imagine the shape of a basket that closes in on a single small object, holding it tightly. Each oxygen and nitrogen points towards the inside of this basket, positioning their lone electron pairs just right to grab a charged metal ion.
Why does it matter? In my experience, working in a research lab that explored the behavior of metal ions in solution, Kryptofix 222 brought reliable results to experiments with radioactive tracers and analytical chemistry. The ability to control where potassium goes opened up precise measurements and creative synthetic work that would otherwise be full of guesswork.
The crown ether structure—especially in this bicyclic form—boosts selectivity and solubility. Potassium ions slip snugly into the cage, leaving behind sodium and other similar-sized ions. In medicine, radiopharmaceutical companies use this precision when tagging molecules with radioactive potassium for tracing in biological systems. The pharmaceutical and nuclear energy fields both use compounds like Kryptofix 222 because sloppy results could have real-world safety consequences.
One issue crops up in every corner: environmental persistence. As useful as these complex molecules are, they rarely break down after use. Working with chemical separation and analysis, it becomes clear that some of these crown ethers stick around in water systems after they finish their original job. Water treatment processes still struggle with removing substances that don’t decompose easily. Strong legislation and smarter material design should focus not only on the performance of a chemical but where those molecules end up later on.
Safer alternatives and better recycling practices matter just as much as the breakthroughs themselves. Research into biodegradable macrocycles is ongoing. Teams in both academic and industrial labs test new ways to build molecules that work hard and then step aside without a trace. With every new design, chemistry laboratories learn a little more about taming the wild power inside these molecular cages—power that, handled right, can keep helping medicine, industry, and science move forward.
Sometimes a package looks harmless or the marketing almost promises safety. A common assumption follows: If it’s on the shelf, harmful effects belong in the past. This thinking doesn’t always line up with reality. Modern supply chains stretch across countries, and ingredients take unexpected routes from source to shop.
Take a popular cleaning spray as an example. Claims of “green” or “eco-friendly” spark the urge to trust it around pets or kids. Yet, surfactants inside can leave residue that irritates lungs with repeated exposure. Ammonia—a traditional cleaning agent—poses risks if mixed with bleach or inhaled over time, increasing chances of respiratory irritation or worse. The American Lung Association reports household cleaning products add to indoor air pollution. The truth: U.S. Poison Control centers receive more than 150,000 exposure calls related to cleaning products in one year.
Every day routines—moisturizing, shaving, or makeup—bring help but sometimes carry hidden issues. A common preservative, parabens, shows up in many products for a longer shelf life. Debate arose after traces appeared in human tissue. Some researchers warn about possible links to hormone disruption, while the FDA argues available amounts remain safe. Similar questions follow talc, especially in powders. Contaminated talc may contain small amounts of asbestos, raising fears about long-term use.
Eating habits offer their own surprises. Artificial dyes and high fructose corn syrup fill processed foods. In 2021, California lawmakers pushed for bans on certain food dyes after health groups connected them to possible behavioral changes in children. Plenty scoff at small amounts of these ingredients. They forget tiny doses over years add up—a truth documented by agencies from the CDC to the European Food Safety Authority.
Children, pregnant people, and those with allergies or asthma make up groups with a sharper risk profile. Even products sold without a warning label may set off asthma or eczema attacks. Fragrance mixes alone can include hundreds of separate chemicals, many never individually tested for chronic exposure.
Growing up, every home had its bottle of bleach under the sink—no child lock, no real warnings. Now, I keep vinegar and baking soda in the cabinet, not out of fear but because past headaches and skin reactions taught me the hard way. Watching friends struggle with unexplained allergies, it clicked: Modern risks rarely announce themselves with fireworks. The best defense is regular curiosity and an extra question or two before each purchase.
Product safety isn’t a finish line but a shifting target. Looking for credible data, testing small batches before full use, and keeping honest about side effects makes for healthier homes and workplaces. Some risks can’t vanish overnight. Still, steady, informed choices help families breathe easier and trust their own judgment more than a flashy label or sales pitch.
| Names | |
| Preferred IUPAC name | Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane |
| Other names |
Kryptofix 222 Cryptand 222 K-222 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane C222 1,4,7,10,13,16,19,22-octaoxa-10,23-diazabicyclo[8.8.8]hexacosane |
| Pronunciation | /ˌhɛksəˈɒksəˌɪlˌɛvənˌtɛnˌdaɪəˈzaˌbaɪsɪkloʊˌeɪtiːnˈeɪtiːnˈeɪtəkˌsoʊn/ |
| Identifiers | |
| CAS Number | 166699-45-6 |
| 3D model (JSmol) | `3D model (JSmol): C1COCCOCCOCCOCCNCCNCCOC(COCCOCCOCCO1)CO` |
| Beilstein Reference | 12043512 |
| ChEBI | CHEBI:143747 |
| ChEMBL | CHEMBL4452061 |
| ChemSpider | 22580219 |
| DrugBank | DB14671 |
| ECHA InfoCard | ECHA InfoCard: 100.149.193 |
| EC Number | 219-226-1 |
| Gmelin Reference | 110306 |
| KEGG | C22118 |
| MeSH | D008654 |
| PubChem CID | 166046752 |
| RTECS number | NL3675000 |
| UNII | 2Z2Q8C13E4 |
| UN number | UN2811 |
| Properties | |
| Chemical formula | C20H44N2O6 |
| Molar mass | 592.68 g/mol |
| Appearance | White solid |
| Odor | Odorless |
| Density | 1.29 g/cm3 |
| Solubility in water | slightly soluble |
| log P | -4.41 |
| Vapor pressure | 2.78E-09 mmHg at 25°C |
| Acidity (pKa) | 13.84 |
| Basicity (pKb) | -2.5 |
| Refractive index (nD) | 1.510 |
| Viscosity | Viscosity: 25.51 cP (25 °C) |
| Dipole moment | 3.4561 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 637.8 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -1542.0 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | –3155 kJ·mol⁻¹ |
| Pharmacology | |
| ATC code | N01AX05 |
| Hazards | |
| Main hazards | May cause respiratory irritation, causes serious eye irritation, may cause skin irritation |
| GHS labelling | GHS07, GHS09 |
| Pictograms | GHS05, GHS07 |
| Signal word | Warning |
| Hazard statements | H317: May cause an allergic skin reaction. |
| Precautionary statements | Precautionary statements: P261, P280, P305+P351+P338, P337+P313 |
| NFPA 704 (fire diamond) | 1-1-0-🟦 |
| Flash point | 235°C |
| Lethal dose or concentration | LD50/oral/rat >5000 mg/kg |
| LD50 (median dose) | LD50: >2000 mg/kg (Rat, oral) |
| NIOSH | NQ9350000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) for 4713162124. Hexaoxa-11,10-diazabicyclo[8.8.8]hexacosane is not established. |
| REL (Recommended) | 0.05 ppm |
| Related compounds | |
| Related compounds |
Kryptofix 222 Kryptofix 221 Kryptofix 21 Kryptofix 211 Kryptofix 23 18-Crown-6 15-Crown-5 12-Crown-4 Cryptand 2.2.2 Polyethylene glycol (PEG) |
