Experimental Enthalpies of Combustion of Organic Materials and The Correlation with Total Number of Bonds, Their Molecular Surface and Volume Properties

Experimentally determined heats of combustion of 21 random diverse organic materials are measured using traditional oxygen bomb calorimetry, as internal energy difference, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Δ</mml:mi> <mml:mi>U</mml:mi></mml:math> , and enthalpy change, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Δ</mml:mi> <mml:mi>H</mml:mi></mml:math> , reveal trends that correlate with their molecular properties which are calculated from the crystal structures. The R² values between <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Δ</mml:mi> <mml:mi>H</mml:mi></mml:math> and total number of covalent bonds, vdW volume, molecular volume, vdW surface area, molecular surface area, solvent accessible surface area and molecular weight are 0.95, 0.91, 0.91, 0.89, 0.87, 0.85 and 0.79, respectively. Oxygen content of the substances increases, rise of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Δ</mml:mi> <mml:mi>H</mml:mi></mml:math> reflected whereas this pattern breaks down when another element is introduced instead. The linear correlations between <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Δ</mml:mi> <mml:mi>U</mml:mi> <mml:mo>,</mml:mo> <mml:mspace></mml:mspace> <mml:mi>Δ</mml:mi> <mml:mi>H</mml:mi></mml:math> and the structure based molecular properties at molecule level described above are not limited, restricted or deviated by the type of elements, H, C, N, O, Cl that make up the materials or molecular class of substance.