Neo Materials / Materials / Fullerene
C₆₀ · TRUNCATED ICOSAHEDRON · Ih SYMMETRY

Fullerene
C₆₀

60 carbon atoms. 20 hexagons. 12 pentagons. The most spherical molecule ever measured. Superconductor when doped. Radical scavenger. Drug delivery cage. Molecular lubricant. Discovered by Kroto, Curl, and Smalley — Nobel Prize 1996.

Request Sample → Enter Lab
0.7 nm Diameter
720.66 u Molecular Mass
-3.7 eV LUMO Energy
46 modes Distinct Vibrations
Interactive Laboratory · 10 Phenomena

INSIDE THE BUCKY BALL

Ten live demonstrations — from quantum vibrations to radical scavenging. Pure CSS, pure physics.

C₆₀: 20 HEXAGONS + 12 PENTAGONS · Ih SYMMETRY GROUP HEX-HEX bond: 1.40 Å HEX-PENT bond: 1.45 Å 60 C atoms total 90 bonds total Ih: 120 symmetry ops HOMO-LUMO gap: 1.9 eV EULER THEOREM: V - E + F = 2 → 60 - 90 + 32 = 2 ✓ (12 pentagons + 20 hexagons)

TRUNCATED ICOSAHEDRON — EULER'S THEOREM

C₆₀ is a truncated icosahedron: vertices=60 (C atoms), edges=90 (C-C bonds), faces=32 (12 pentagons + 20 hexagons). Euler: V-E+F=2 ✓. Symmetry group Ih has 120 operations. Two distinct bond lengths: hex-hex 1.40 Å (double bond character) and hex-pent 1.45 Å (single bond). Curvature costs 8 kcal/mol strain energy distributed across 12 pentagons — isolated pentagon rule (IPR). Smallest stable fullerene satisfying IPR.

46 DISTINCT VIBRATIONAL MODES · CAGE BREATHING AT 273 cm⁻¹ Ag(1) BREATHING MODE — 273 cm⁻¹ IR SPECTRUM (4 active modes) 527 576 1183 1428 cm⁻¹ → T(%) ↑ 4 IR active (T1u), 10 Raman active (Ag+Hg) 46 distinct modes: 2Ag + 3F1g + 4F2g + 6Gg + 8Hg + F1u + 4F2u + 5Gu + 6Hu

VIBRATIONAL SPECTROSCOPY — 46 MODES, 4 IR-ACTIVE

Ih symmetry restricts C₆₀ to 46 distinct vibrational modes (3N-6=174 total, but symmetry reduces them). Only 4 modes are IR-active (T₁ᵤ symmetry) at 527, 576, 1183, 1428 cm⁻¹. 10 Raman-active modes (2Ag + 8Hg). Ag(1) "breathing" mode at 273 cm⁻¹ — all atoms move radially. Ag(2) "pentagonal pinch" at 1469 cm⁻¹ — monitors charge transfer when doped. Used as fingerprint for fullerene identification and doping level measurement.

K₃C₆₀ SUPERCONDUCTOR — Tc = 18K · BCS MECHANISM FCC C₆₀ + K⁺ IN OCTAHEDRAL/TETRAHEDRAL VOIDS K⁺ K⁺ COOPER PAIR FORMATION C₆₀³⁻ Tc = 18K (K₃C₆₀), 40K (Cs₂RbC₆₀) — highest molecular superconductor λ_ep = 0.6-1.0 (intermediate coupling BCS) · 3 K⁺ donate e⁻ to t1u LUMO

ALKALI-DOPED FULLERENE SUPERCONDUCTOR — K₃C₆₀

Intercalating 3 K atoms per C₆₀ fills the triply-degenerate t₁ᵤ LUMO with 3 electrons. Half-filled band → metallic. Intramolecular phonons (Hg modes) mediate BCS Cooper pairing. Tc = 18K (K₃C₆₀), 33K (RbCs₂C₆₀), 40K (pressure-enhanced Cs₂RbC₆₀). McMillan equation: Tc ∝ exp(-1/λ-µ*), λ_ep ≈ 0.8. Density of states at Fermi level N(EF) = 20 states/eV/molecule — high value despite narrow bandwidth. BCS coherence length ξ₀ = 26 Å.

DRUG DELIVERY — HYDROPHOBIC CAGE ENCAPSULATION + pH RELEASE DRUG TUMOR CELL pH 5.5 (acidic) BLOODSTREAM: pH 7.4 → cage stable, drug retained TUMOR (endosome): pH 5.5 → hydrolysis of ester linkage → drug RELEASE Loading capacity: up to 5 drug molecules per C60 via non-covalent encapsulation

pH-TRIGGERED DRUG DELIVERY — ACID-LABILE LINKERS

C₆₀ hydrophobic interior encapsulates 1–5 drug molecules (van der Waals interaction, ~5 kcal/mol per drug). Surface functionalization (-COOH, PEG) enables water solubility and EPR (Enhanced Permeability and Retention) effect for tumor targeting. pH-sensitive acyl hydrazone or ester linkers cleave at endosomal pH 5.5 (normal tissue: 7.4). Drug loading efficiency 15–30% w/w. C₆₀-paclitaxel conjugates show 10× lower IC₅₀ vs free drug in vitro. Circulation half-life extended 4× by PEGylation.

ORGANIC PHOTOVOLTAIC: P3HT DONOR + PCBM (C₆₀) ACCEPTOR ITO anode P3HT DONOR LAYER (polymer) PCBM ACCEPTOR (C₆₀ derivative) Al cathode hν D-A INTERFACE — EXCITON DISSOCIATION h⁺→ITO e⁻→Al C₆₀ LUMO = -3.7 eV (strong electron acceptor) · HOMO = -6.2 eV P3HT HOMO = -5.1 eV · LUMO = -3.0 eV · Driving force ΔΔE = 0.7 eV Electron transfer rate: k_ET > 10¹² s⁻¹ (ultrafast, 45 fs after excitation) OPV PCE: 8-10% (bulk heterojunction) · Exciton diffusion length ~10 nm

FULLERENE AS ELECTRON ACCEPTOR — LUMO = -3.7 eV

PCBM (phenyl-C₆₁-butyric acid methyl ester) is the dominant n-type semiconductor in organic photovoltaics. LUMO = -3.7 eV makes C₆₀ the strongest molecular electron acceptor available. Photoinduced electron transfer from P3HT (HOMO -5.1 eV) to PCBM LUMO occurs in 45 fs — faster than exciton recombination (ns). Marcus theory rate: k_ET = (4π²/h)·|V|²·FC, where V = electronic coupling ~20 meV. Bulk heterojunction morphology optimizes D-A interface area. OPV efficiency record 18.5% (tandem).

C₆₀ AS MOLECULAR BALL BEARING — ULTRA-LOW FRICTION UPPER SURFACE (moving →) LOWER SURFACE (stationary) FRICTION COEFFICIENT COMPARISON: C₆₀: µ = 0.02 (rolling) Graphite: µ = 0.08 Rolling vs sliding: C₆₀ reduces friction 4× vs graphite Hertz contact pressure: P = 4E*/3·(R·δ)^0.5 at each ball

C₆₀ AS NANOSCALE BALL BEARING — ROLLING FRICTION µ = 0.02

The near-perfect spherical geometry of C₆₀ enables true rolling motion between surfaces — friction coefficient µ = 0.02, compared to µ = 0.08 for graphite flakes (sliding). Hertz contact mechanics applies: contact area ∝ (F·R/E*)^(2/3). Rolling friction F_roll = µ·F_normal. Van der Waals adhesion gives slight elastic contact — no plastic deformation. C₆₀-based lubricants operate at 300°C in vacuum, unlike oil-based lubricants. Used in space mechanisms, hard disk sliders, and MEMS tribology where contamination is critical.

ARC DISCHARGE SYNTHESIS — KRÄTSCHMER-HUFFMAN (1990) C anode C cathode He 100 Torr SOOT DEPOSIT (10-15% C₆₀ + C₇₀ + higher fullerenes) 25V DC 150A EXTRACTION: soot + toluene → filter → evaporate → C₆₀ crystals (fcc, a=14.17 Å)

KRÄTSCHMER-HUFFMAN ARC SYNTHESIS — 1990 BREAKTHROUGH

Graphite rods in 100 Torr He atmosphere, 25V/150A DC arc. Carbon plasma at 3,500°C evaporates anode. In He buffer, C atoms cluster: C₂ → C₆₀ condensation follows top-down fragmentation or bottom-up assembly — still debated. Soot contains 10–15% C₆₀, 5–8% C₇₀, remainder higher fullerenes (C₇₆, C₈₄, etc.). Extraction: toluene dissolution, HPLC purification yields 99.9% C₆₀. Yield 1 g C₆₀ per 10g graphite. Commercial scale: 1 kg/day reactors now available. Price: ~$50/g (99.9% purity).

ENDOHEDRAL FULLERENE — ATOM TRAPPED INSIDE: La@C₈₂ La³⁺ 3e⁻ transfer to cage LUMO La@C₈₂ (not C₆₀) He@C₆₀: confirmed Cage intact VdW confinement MRI contrast agent NOTATION: A@C₆₀ (@ = "at" = inside). He@C₆₀: quantum tunneling traps He inside cage permanently Gd@C₆₀: MRI contrast agent · T1 relaxivity 80× greater than clinical Gd-DTPA

ENDOHEDRAL FULLERENES — ATOMS INSIDE THE CAGE

La@C₈₂: lanthanum atom confined inside C₈₂ cage. La donates 3 electrons to cage (ionic state La³⁺·C₈₂³⁻). The trapped atom "rattles" in the cavity — quantum zero-point motion confined to ~0.3 nm³ volume. He@C₆₀: helium trapped by quantum tunneling through cage wall (activation energy 10 eV). Applications: Gd@C₈₂ has MRI T₁ relaxivity 80× higher than Gd-DTPA. ¹³¹I@C₆₀ enables targeted radiotherapy. H₂@C₆₀ (ATOCAP method) stores molecular hydrogen with quantum confinement modifying ortho/para ratio.

ENERGY LEVEL DIAGRAM — S₀→S₁→T₁ INTERSYSTEM CROSSING (φ_ISC=1.0) ENERGY S₀ 0 eV S₁ 1.9 eV T₁ 1.57 eV hν abs 340nm ISC φ=1.0 T₁→S₀ τ=40µs 720nm hν' UV-VIS ABSORPTION 340nm 530nm 300 λ(nm) 700 φ_F(fluorescence) ≈ 3×10⁻⁴ · φ_ISC = 1.0 · τ_T = 40µs · Singlet O₂ sensitizer

ULTRAFAST INTERSYSTEM CROSSING — φ_ISC = 1.0

C₆₀ absorbs strongly at 340 nm (ε = 3.3×10⁴ M⁻¹cm⁻¹), exciting to S₁ (1.9 eV). Quantitative intersystem crossing (φ_ISC = 1.0) to T₁ (1.57 eV) occurs in 1.2 ns via spin-orbit coupling — enabled by high symmetry reducing radiative rate. Triplet lifetime τ_T = 40 µs (air-free). Triplet sensitizes ¹O₂ (singlet oxygen): ³C₆₀ + ³O₂ → C₆₀ + ¹O₂. Singlet O₂ quantum yield Φ_Δ = 0.96. Foundation for photodynamic therapy (PDT). Fluorescence φ_F = 3×10⁻⁴ (very weak — all energy goes to triplet).

RADICAL SCAVENGING — UP TO 34 •OH RADICALS PER C₆₀ •OH •OH •OH O₂•⁻ C₆₀ → C₆₀(OH)ₙ Fullerenol MECHANISM: C₆₀ + n(•OH) → C₆₀(OH)ₙ (n up to 34) Rate constant k = 5×10⁸ M⁻¹s⁻¹ (diffusion-limited with •OH) Neuroprotective: reduces oxidative stress in Parkinson's/ALS models by 80%

RADICAL SPONGE — 34 FREE RADICALS PER MOLECULE

C₆₀'s low-lying LUMO (-3.7 eV) accepts electrons from free radicals at near-diffusion-limited rates: k(•OH) = 5×10⁸ M⁻¹s⁻¹. Up to 34 hydroxyl radicals can add to form fullerenol C₆₀(OH)₃₄. Three scavenging mechanisms: (1) radical addition to π-system, (2) electron transfer, (3) hydrogen atom abstraction. Fullerenol is water-soluble — enabling biological applications. Neuroprotective studies: 80% reduction in ROS-induced cell death in ALS motor neuron models at 1 µM concentration. No confirmed toxicity in properly-functionalized water-soluble forms.

Key Properties

C₆₀ — THE MOLECULE THAT CHANGED MATERIALS SCIENCE

Structure

  • 60 C atoms, Ih symmetry
  • 20 hexagons + 12 pentagons
  • Diameter: 0.7 nm
  • HOMO-LUMO: 1.9 eV gap

Reactivity

  • LUMO: -3.7 eV
  • Scavenges 34 •OH
  • ISC quantum yield: 1.0
  • Singlet O₂ sensitizer

Special States

  • Superconductor @ 18–40K
  • Endohedral: A@C₆₀
  • Fullerenol water-soluble
  • Molecular lubricant µ=0.02

WORK WITH FULLERENE C₆₀?

We supply 99.9% purity C₆₀ and custom functionalized derivatives (fullerenol, PCBM, amino-C₆₀) for research and industrial applications.

Request Sample → ← All Materials