Thermodynamic Properties of Adamantane Revisited

Abstract

The heat capacity and parameters of the solid-to-solid phase transition of adamantane were measured in the temperature range from 80 to 370 K by use of adiabatic calorimetry. The thermodynamic functions for the compound in the crystalline and liquid states were calculated. The standard molar enthalpy of formation in the crystalline state for adamantane was obtained from combustion calorimetry by use of two different calorimeters. Available data on the enthalpy of combustion, saturated vapor pressure, and enthalpy of sublimation of adamantane were collected, analyzed, and selected. On the basis of spectroscopic data and results of quantum-chemical calculations, the ideal-gas properties for adamantane were calculated by a statistical thermodynamics method.

Novel silver(I) compounds with 1-adamantanamine

“…In order to determine accurately the combustion enthalpy of adamantane, its derivatives and complexes, the samples should be combusted in a calorimetric bomb under high pressure. 25 Thus, atomic absorption measurements were performed as a substitute. The calculated value for the total silver in bis(1adamantanamine)silver(I) nitrate hemimethanolate is 22.09 %, while the determined value was 21.9±0.1 %.…”

Atmospheric pressure synthesis of diamondoids by plasmas generated inside a microfluidic reactor

“…The sample cylinder, the tubings of the inlets and the microreactor were all heated to an average temperature of 323 K, to increase the amount of adamantane in the gas phase. The adamantane concentration was estimated from the sublimation pressure p Ada of adamantane, which is given by ln(p Ada /kPa)= 50.9129 − 8494.5 ⋅ (T/K) −1 − 4.6395 ⋅ ln (T/K), which is valid for T = 254 K to 543 K [34]. The concentration of adamantane in the gas phase, ρ, was evaluated assuming that the feed gasadamantane mixture is a perfect gas, and for T = 323 K, ρ~5.6 g m −3 .…”

“…Table 1 Experimental conditions adopted for the diamondoid synthesis. The adamantane concentration ρ was estimated from its vapor pressure [34]. For a temperature of 323 K, the adamantane vapor pressure is about 0.11 kPa, which corresponds to an adamantane content in the gas of about 0.1%.…”

Six-membered ring aliphatic compounds: A search for regularities in phase transitions

“…Crystals of a highly disordered phase stable just below the melting point (phase I) are generally referred to as plastic crystals [4]. Study of phase transitions in adamantane [5] and its derivatives [6] has been a longstanding goal in our group. In this paper, we focus our interest on studies of the solid-liquid, solidgas, and liquid-gas phase transitions of halogen-substituted adamantanes.…”