fullerene

Cage atom assignment

Record the proposed cage atom count and competing explanations for the observed molecular signal.

1. Which atoms belong to the cage, and which belong to guests, substituents, counterions or analytical adducts? definition
2. What mass, isotope-pattern or complementary evidence supports the cage formula rather than a fragment or cluster assignment? measurement

Supported cage structure

Keep experimentally supported connectivity separate from a plausible structural drawing.

1. What evidence establishes a discrete closed cage rather than an open carbon fragment or extended structure? boundary
2. Which connectivity or symmetry assignment is supported by diffraction, spectroscopy or comparison with an identified reference, and which alternatives remain? measurement
3. Is the structural assignment measured for this material, inherited from a supplier or inferred computationally? provenance

Modification assignment

Record group count and positional uncertainty independently; NIST describes mass-spectrometric quantification of groups attached to fullerene cages. [NIST](https://www.nist.gov/programs-projects/macromolecule-and-nanoparticle-composition-and-architecture)

1. Which attached groups and addition counts are established, and are their attachment positions resolved? measurement
2. What evidence places a proposed guest inside the cage rather than on its exterior or between neighbouring cages? boundary
3. Which parent cage does this modified species derive from, and does the registry treat it as within this entry? definition

Current cage state

Describe the material before analysis separately from changes introduced by measurement or treatment.

1. What charge state and counterions are supported under the recorded sample conditions rather than solely in the mass spectrometer? measurement
2. Has treatment opened, fragmented or covalently linked cages, and what evidence establishes the remaining cage integrity? boundary

Quantified fullerene fraction

Record the abundance of assigned species with an explicit analytical basis.

1. Which cage sizes, isomers and derivatives are resolved, and what fraction remains unidentified or co-eluting? measurement
2. Does the reported purity represent calibrated mass or mole fraction, chromatographic area, or another basis? measurement
3. Which extraction, purification and solvent-removal steps could account for residual solvent, other carbon material or metal contamination? provenance

Observed assembly state

Record aggregation or solid-state organisation without changing the underlying molecular identity by assumption.

1. What evidence distinguishes molecular dissolution from a colloidal dispersion or suspended crystallites? measurement
2. What aggregate distribution or crystal-phase assignment is observed, under which medium, concentration, temperature and ageing conditions? measurement

Response attribution

Associate measured features with a stated species and sample state, preserving competing assignments.

1. Which spectral features support this cage assignment, and what reference, medium and instrument conditions make the comparison valid? measurement
2. Which redox transitions are observed, against what reference electrode, and with what evidence of reversibility or chemical change? measurement

Observed change window

Record demonstrated stability intervals and distinguish cage chemistry from physical redistribution.

1. Over what tested time, temperature, atmosphere and illumination range does the identified species remain unchanged within detection limits? measurement
2. Does signal loss indicate chemical transformation, precipitation, aggregation or adsorption to the container? boundary

Preparation fit

Relate purification, solvent exchange and dispersion preparation to explicit acceptance criteria.

1. Which separation or preparation method is supported for this cage and modification state, and what purity or dispersion target must it meet? action
2. Which post-operation measurements will verify cage retention, recovered composition and the intended molecular or aggregate state? action

Supported operation

Require evidence matching the identified species and distinguish a proposed outcome from a demonstrated one.

1. What evidence supports the proposed functionalisation, charging or irradiation conditions for this cage, including likely product mixtures? action
2. What result would establish suitability for the requested role, and which unverified assumptions currently prevent that decision? action
3. Which observed changes require reassessment before further use or after storage? action

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• (C60-Ih)[5,6]fullerene (buckminsterfullerene, buckyball)
• (C70-D5h(6))[5,6]fullerene
• Higher empty cages and their IPR isomers (C76, C78, C84 and related)
• Endohedral fullerenes and metallofullerenes (M@Cn, noble-gas or small-molecule guests)
• Heterofullerenes and fulleroids (opened, inserted, or hetero-substituted cages)
• Exohedral adducts and hydroxylated/hydrated fullerenes (fullerenols)
• Hydrogenated fullerenes (fulleranes)
• As-produced fullerene soot and mixed higher-fullerene fractions

1. Which of these kinds and varieties hold for the sense of fullerene this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• IUPAC systematic name - (Cn-<Schoenflies point group>)[5,6]fullerene - Parent examples: (C60-Ih)[5,6]fullerene and (C70-D5h(6))[5,6]fullerene; bracketed ring sizes are required when rings other than 5 and 6 occur.
• CAS Registry Number - 99685-96-8 - [5,6]Fullerene-C60-Ih / buckminsterfullerene.
• CAS Registry Number - 115383-22-7 - Fullerene C70.
• EC number - 628-630-7 - Fullerene C60, as cited by SCCS.
• PubChem CID - 123591 - C60; C70 is CID 16131935.
• ChEBI - CHEBI:33128 - C60 fullerene.
• MeSH - D037741 - Class heading Fullerenes (polyhedral carbon cages, typically ~60-80 carbons).
• UNII - NP9U26B839 - C60.
• EPA CompTox - DTXSID4031772 - C60.
• ChemSpider - 110185 - C60.
• ECHA InfoCard - 100.156.884 - C60.
• Wikidata - Q3885009 - C70 fullerene; the class item for fullerene was not confirmed in the pages read.

1. Which of these identifiers and schemes hold for the sense of fullerene this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• IUPAC: Nomenclature for the (C60-Ih)[5,6] and (C70-D5h(6))[5,6] fullerenes (Pure Appl. Chem. 74, 629-695, 2002).
• IUPAC: Numbering of Fullerenes (Pure Appl. Chem. 77, 843-923, 2005), covering cages from C20 to C120.
• EU CLP (Regulation (EC) No 1272/2008): C60 typically classified Eye Irrit. 2 (H319) and STOT SE 3 (H335).
• EU SCCS: cannot conclude on the safety of fullerenes and (hydrated) hydroxylated fullerenes in cosmetics; genotoxicity of C60 and C70 cannot be excluded.
• OECD WPMN manufactured-nanomaterial dossier Fullerenes (C60), ENV/JM/MONO(2016)21.
• JIS Z 8981:2010 (Japanese Industrial Standards): HPLC quantification of [60]fullerene and [70]fullerene.
• US TSCA inventory listing for [5,6]Fullerene-C60-Ih (CAS 99685-96-8).
• Japan NEDO nanomaterial risk-assessment project: recommended occupational exposure value 0.39 mg/m³ for fullerenes (project recommendation, not a statute).

1. Which of these standards and regulation hold for the sense of fullerene this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Produced by graphite arc discharge or combustion soot and sold as black crystalline research solids that dissolve in hydrocarbon solvents (C60 solutions are purple).
• Notified as a cosmetic nanomaterial (pristine C60 and hydroxylated/hydrated forms, e.g. 'Radical Sponge' type products); EU SCCS still cannot conclude safety.
• Used in electronics and energy materials and in experimental diagnostics and medicine, though few bulk industrial applications of unmodified C60 are established.
• Occupationally encountered as dry powder during production, weighing, transfer and ultrasonic dispersion; airborne mass is usually agglomerated rather than free 0.7 nm cages.
• Occurs in trace amounts in sooty flames and lightning discharges, and is the carbon allotrope that is soluble in ordinary organic solvents at room temperature.

1. Which of these real-world use hold for the sense of fullerene this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• C60 cage diameter - about 0.7 - nm
• C70 cage axes - about 0.8 × 0.7 - nm
• Carbon atoms in the cage (n) - ≥ 20, even; common isolated cages 60 and 70 - atoms
• Agglomerate / crystallite mass-median diameter (commercial C60 powder) - 20-30 - nm
• Specific surface area (BET, ISO 9277, Nanom Purple) - 0.87 - m²/g
• Zeta potential (aqueous dispersion used in mammalian tests) - about −20 - mV
• Pour density - 0.838 - g/cm³
• Occupational airborne nanoparticle-fraction mass - 0.12-1.2 - μg/m³
• Proposed Japanese occupational exposure value (NEDO) - 0.39 - mg/m³
• Commercial C60 purity - >99 to >99.8 - % w/w

1. Which of these typical measurements hold for the sense of fullerene this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• CLP hazards for typical C60 powder: serious eye irritation (H319) and respiratory-tract irritation (H335).
• C60 solutions that have been exposed to light have been associated with tumour risk if ingested; light-protected handling is required for any ingestible formulation.
• SCCS cannot exclude genotoxicity of C60 and C70, so cosmetic nanomaterial safety remains unresolved.
• Inhaled well-dispersed C60 causes only slight, transient pulmonary inflammation in rodents and is much less fibrogenic than carbon nanotubes, but agglomeration changes the relevant dose metric.
• Pristine C60 is poorly absorbed by oral, respiratory and dermal routes; intravenous or intraperitoneal administration can load liver, spleen and kidney and has harmed mouse fetuses in those unnatural routes.
• Fullerene soot and hydroxylated derivatives are not toxicologically interchangeable with empty C60; surface chemistry and guest atoms can dominate hazard.
• Confusing fullerenes with carbon nanotubes overstates asbestos-like fibre risk: IARC/NIOSH fibre concerns attach to high-aspect-ratio tubes, not to closed ~1 nm cages.

1. Which of these failure modes and hazards hold for the sense of fullerene this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Sinophone names diverge: mainland China 富勒烯, Taiwan 球碳, Hong Kong 布克碳; informal 足球烯 / 巴克球 also occur, and written forms include [60]富勒烯, 碳60 and C60.
• Japan has a dedicated HPLC standard (JIS Z 8981:2010) and a NEDO-project OEL of 0.39 mg/m³ that other regions have not adopted as a statutory limit.
• The EU treats cosmetic fullerenes as notifiable nanomaterials under CLP/SCCS review; the United States lists C60 on TSCA without a NIOSH REL specific to fullerenes (NIOSH RELs cited in the same literature are for CNTs/CNFs).
• Older and some popular Chinese sources still list carbon nanotubes as a kind of fullerene; current IUPAC and materials practice restrict fullerene to closed cages and treat tubes as a separate nanoform.

1. Which of these regional variation hold for the sense of fullerene this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Carbon nanotube (SWCNT/MWCNT) - A nanotube is a high-aspect-ratio cylinder; a fullerene is a closed 0-D polyhedral cage. Separate them by morphology (TEM/SEM aspect ratio) and by the much higher pulmonary/fibre hazard of some MWCNTs (NIOSH REL 1 µg/m³; IARC 2B for Mitsui-7) versus low C60 lung toxicity.
• Graphene - Graphene is an open 2-D hexagonal sheet; a classical fullerene needs twelve pentagons to close. Separate by dimensionality and by the presence of pentagons / a discrete Cn molecular ion in mass spectrometry.
• Soot / carbon black - Soot is a mixed amorphous/graphitic solid; molecular C60/C70 are HPLC-isolable cages (JIS Z 8981:2010) and, unlike other carbon allotropes, dissolve in ordinary organic solvents.
• Graphite - Graphite is an extended stacked sp² solid of hexagons only; fullerenes are discrete, solvent-soluble cages whose curvature comes from pentagons.
• Fulleroid / heterofullerene / secofullerene - These resemble the cage but fail the IUPAC closed-cage, all-carbon, three-coordinate definition (opened bonds, inserted atoms, or heteroatoms). Separate by molecular formula and by whether the cage remains a closed Cn polyhedron.
• Onion-like carbon - Concentric multi-shell nanoparticles versus a single molecular cage; TEM shows nested shells, whereas C60/C70 give discrete molecular masses and HPLC peaks.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of fullerene this model covers, and on what evidence? provenance