The stabilization profile and a simple Coulomb model for the π-resonant electrons in conjugated oligoenes and oligoynes

This study proposes a simplified Coulombic model for the potential energy of resonant π-electrons in oligoenes and oligoynes, termed the snapshot model. The model shows that attractive electron-nucleus interactions dominate the net potential energy, with contributions represented by n2(2m+1) where m+1 = n. Application to hexatriyne reveals that potential energy profiles along the carbon chain mirror molecular topology. Experimental validation demonstrates strong predictive capability: the model exhibits logarithmic correlation with maximum wavelength absorption (λmax) for oligoenes (R2 = 0.98), enabling a priori prediction of optical properties from fundamental constants alone. Predictive power extends to thermodynamic properties, with logarithmic relationships to heat of combustion and parametrized heat of combustion for oligoynes. This cross-validation across multiple observables and molecular classes establishes the snapshot model as a robust predictive tool. The logarithmic relationships elucidate asymptotic saturation of conjugation stabilization, showing that physics-based simplified models can achieve predictive accuracy rivaling sophisticated computational methods.