Thermodynamic properties of 1,3,5-trithiane derived from solid phase heat capacity measurements by adiabatic calorimetry and DSC measurements in the melting range

Abstract

The thermal properties of 1,3,5-trithiane were measured with adiabatic calorimetry and DSC between 15 and 500 K. It was necessary to purify the compound even as the stated purity of the commercial product was >99%. The impurity present triggers a reaction at the melting point. The absolute entropy at 298.15 K was measured to be (156:2 AE 0:8) J K À1 mol À1 , the enthalpy increment from 0 to 298.15 K is (22936 AE 100) J mol À1. The enthalpy of melting was found to be (32:2 AE 0:3) kJ mol À1 , the fusion temperature 488.4 K. The molar heat capacity of the solid between 100 and 380 K can be described by a polynomial function C p ¼ f24:17 þ 0:4004T À 9:9605:10, the standard deviation of this fit is 0.24 J K À1 mol À1. #

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at and around 298.15 K Based on Their “True” Molecular Volume

“…In Table 19 and Table 20 a number of examples demonstrates the expandability of the present Cp-prediction method to a range of temperatures. For many compounds, nearly perfect linearity of the temperature dependence of the heat capacity in the range between 250 and 350 K has been graphically demonstrated (specifically for hexatriacontane [51], alkylsubstituted adamantanes [53], neopentylbenzene [54], 4,4′-disubstituted biphenyls [59], tetracene and pentacene [62], 2-propenol and cyclohexylalcohols [76], adamantanols [77], monoterpenoids [85], a,ω-alkanediols [88], 1,2-cyclohexanediol [99], ribose and mannose [100], ketohexoses [101], glucose [102], sugar alcohols [103], 3,5-di-t-butylsalicylic acid [111], 2-pyrazinecarboxylic acid [116], vitamin B3 [118], 2,4-dinitrobenzaldehyde [145], various monoterpenes [147,148], 2-pyridinealdoxime [164], chloroanilines and chloronitrobenzenes [166], linear alkyldiamides [170], 2-thiobarbituric acids [175], monuron [179], 1,3,5-trithiane [189], ferrocene derivatives [198,199], cyclic siloxanes [202], adenosine [206], tryptophan [210], carnitine [211], 2-(chloromethylthio)benzothiazole [231], 2-amino-5-nitropyridine [233], 2-aminopyridine [234], 4-dimethylaminopyridine [236], 8-hydroxyquinoline [237], caffeine [238], 4′-bromomethyl-2-cyanobiphenyl [249], myclobutanil [250], fenoxycarb [251], methylprednisolone [254], N -methylnorephedrine [255], N , N -dimethylnorephedrine hydrochloride [256], risperidone […”