Bond Energies and Bond Distances of Hydrocarbons

The relations between carbon-carbon bond energies [B(CC)] and distances [R(CC)] and carbon-hydrogen bond energies [B(CH)] and distances [R(CH)] are taken to be a parabola and a straight line, respectively, B(CC)=1450.762–1644.151·R(CC)+491.936·R(CC)2and B(CH)= 252.956− 141.721·R(CH),yielding B(CH)= 98.104− 0.075·B(CC)+[3.196·B(CC)−246.048]12and R(CH)= 1.396− 0.594·R(CC)+0.261·R(CC)2.This system of equations is based on the assumption that the heat of sublimation of carbon L(C)=169.75 kcal. Similar relations with L(C)=124.3 and 135.8 kcal are also derived.