TABLE 3.

Calculated Quantum Mechanical Parameters for Electrophiles

Electrophile	ELUMO (eV)	EHOMO (eV)	η	ω
n-Hexane	2.52	− 8.28	5.40	0.77
HD	− 0.44	− 6.70	3.13	2.04
Acrylamide	− 0.86	− 6.77	2.95	2.46
Acrolein	− 1.70	− 6.98	2.64	3.57

Note. LUMO, lowest unoccupied molecular orbital; HOMO, highest occupied molecular orbital. The LUMO energies (E_LUMO) and the HOMO energies (E_HOMO) were calculated using Spartan04 (version 1.0.3) software (Wavefunction, Inc., Irvine, CA). Global (whole molecule) hardness (η) was calculated as η = (E_LUMO − E_HOMO)/2 and the electrophilicity index (ω) was calculated as ω = μ²/2η, where μ is chemical potential of the electrophile and was calculated as μ = (E_LUMO + E_HOMO)/2 (for details, see LoPachin et al., 2008). The ω parameter is a measure of the electrophilic reactivity of a given chemical. Data indicate that HD and parent hexacarbon are harder (higher η value) electrophiles than the α,β-unsaturated carbonyls, acrylamide, and acrolein. However, HD is a significantly weaker electrophile (lower ω value) than acrylamide or acrolein.