Methods for calculating the enthalpies of sublimation of organic molecular crystals

Synthesis, Structural Characterization, and Crystal Packing of the Elusive Pentachlorinated Azafullerene C59NCl5

“…On average it can be counted as 8 kcal mol −1 for each of 12 nearest neighbours. Thus, the enthalpy of sublimation can be estimated as (12×8+16.8×2)/2≈57 kcal mol −1 , which is remarkably high . This also agrees surprisingly well with results obtained by Tabernero (50 kcal mol −1 ), although an additive model was parametrized without using of fullerene containing moieties.…”

Relationship between molecular descriptors and the enthalpies of sublimation of natural amino acids

“…(1) and the absolute error calculated from (±δ) = Δ sub (exp) -Δ sub (calc) are presented in Table 1. It should be noted that the average relative error for amino acids was 5.5%, which was comparable to those for the physicochemical properties of substances obtained using correlation ratios in [13,14,16,17,25] (from 5 to 12%). Satisfactory agreement between the calculated and measured values of enthalpy of sublimation for natural amino acids was thus observed.…”

“…The values for other substances were taken from [13,16]. The sublimation of aromatic aminoacids (L-phenylalanine, L-tryptophane, L-tyrosine) was studied using the Knudsen effusion technique with control of the steam composition.…”

“…Experimental and literature data on the enthalpy of sublimation were analyzed in [13,16,17,19], and the relationships between Δ sub and the ISA index were established. The values of the ISA and the enthalpy of • aliphatic amino acids: Gly < Ala < Val < Leu;…”

“…Such methods are concerned mainly with organic substances that contain neither nitrogen nor oxygen atoms, so theoretical estimates of Δ sub for amino acids and peptides are still of great interest [6,[13][14][15]. To solve this problem, we should consider the approaches that are used most widely: the additive group contribution method, the structure-property correlation method, and the atom-atomic potential method [13][14][15][16][17][18].…”