Multi-substitution KMCLeap engine

Free Radical Chlorination

Multi-chlorination through CCl4, ethane from methyl recombination, and ethane chlorination under sequential photons. Sweep the CH₄:Cl₂ mole ratio — excess chlorine drives polychlorination.

Initial conditions

Scale the batch, then pick any integer CH₄:Cl₂ ratio from 10:1 to 1:10. Above 50,000 molecules uses the leap engine.

Batch size(majority reactant)

Mole ratio CH₄ : Cl₂1 : 1

CH₄1 mol (N_A)

6.022×10²³ molecules

Cl₂1 mol (N_A)

6.022×10²³ molecules

Near-equimolar feed — mixed mono- and polychlorination.

Photons (sequential)5

Irradiation dose. At mole scale this drives the batch toward the Cl₂ / C–H limit, so excess chlorine really does polychlorinate. Extra photons also add termination (ethane).

Monte Carlo trials600

Fixed seed(reproducible)

Leap engine: irradiation dose toward the Cl₂ / C–H limit, competitive multi-sub leaps, then termination. Excess chlorine now polychlorinates.

Rate constants

Abstraction scale and termination. Substrate selectivities are built-in (CH4 less reactive than CH3Cl and C2H6).

Abs. scale (Cl• + RH)1.00

Prop. R• + Cl₂1.00

Term. Cl• + Cl•50.00

Term. R• + R•50.00

Term. R• + Cl•50.00

Expanded mechanism

Multi-chlorination of methane, ethane from methyl recombination, and ethane chlorination when further photons hit the mixture.

Initiation

Cl₂ + hν2 Cl•Per photon

Multi-substitution

CH₄CH₃Cl → CH₂Cl₂ → CHCl₃ → CCl₄Cascade
Cl• + RHHCl + R•Competing substrates
R• + Cl₂RCl + Cl•Regenerates Cl•

Ethane branch

•CH₃ + •CH₃C₂H₆Termination
C₂H₆C₂H₅Cl → C₂H₄Cl₂ → C₂H₃Cl₃Later photons

Termination

Cl• + Cl•Cl₂Recombination
R• + Cl•RClCross-term.
R• + R•R−RIncl. ethane

Cl• chooses substrates by relative rate × concentration, so as CH₃Cl builds up it competes with CH₄ — classic multi-substitution. Ethane only forms on •CH₃+•CH₃ termination; raise photons so later chains chlorinate that C₂H₆.

Results

Product distribution, conversion, and chain statistics

No organic products yet

Mean organic product share (chloromethanes + ethane series)

Ensemble statistics

Conversion and chain length

Statistics appear after you run the ensemble

Latest run detail

Photons into one mixture · multi-substitution + ethane branch

Run a simulation to inspect products.

Reading multi-substitution

Cl radicals attack every RH present. Relative rates make CH3Cl and further products competitive, so long chains yield a product slate, not pure CH3Cl. Slide the mole ratio toward 1 : 10 (excess Cl₂) to push the slate toward CH2Cl2, CHCl3, and CCl4.

Ethane forms when two methyl radicals recombine. Raise photons so later chains chlorinate C2H6 to C2H5Cl, C2H4Cl2, and C2H3Cl3.