Additivity of guest and host properties in clathrates: a thermodynamic and Raman spectroscopic investigation of HPTB-based solids

Abstract

The heat capacities of hexakis(phenylthio)benzene (abbreviated as HPTB) and the clathrate have been determined from 30 to about 300 K. In addition, the room-temperature Raman spectra have been obtained for both compounds. The Raman spectrum of is very closely approximated by the sum of the spectrum of HPTB and that of pure , indicating the additivity of the guest and host intramolecular interactions. These internal degrees of freedom dominate the heat capacity, and the present analysis shows the importance of the low-frequency modes. Over a wide range of temperature below 200 K, the calculated Grüneisen parameter of HPTB is higher than for .

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of the Group-Additivity Method

“…A number of new experimental C p data have been published for saturated and unsaturated hydrocarbons, especially for bicyclo [ [14], and adamantane [15]. In addition, further C p values have been found for the amines hexamethylenetetramine [15], tetra-N-phenylbenzidine and 4,4 -bis (N-carbazolyl)-1,1 -biphenyl [16], 1,3,5-triazine [17], the ethers 1,3,5-trioxane [17], diethylene glycol n-pentyl ether [18], triethylene glycol monopentyl ether [19] and diphenyl ether [20], several alcohols and aldehydes [21], derivatives of glycidol [22], carboxylic acids [23,24], aliphatic esters [24][25][26][27], benzoates [28], haloalkanes [29,30], haloaromatics [31,32], thio ethers, sulfones and sulfoxides [33,34], alkanolamines, [35][36][37] and nitriles [38] For several compounds, more recent publications have been found the following: 4-ethylmorpholine [39], methionine [40], theophylline, and caffeine [41], as well as for (-)-menthone, (+)-pulegone, and (-)-isopulegol [42]. Beyond these, experimental C p values of a number of new compounds have been published: namely 3-amino-4-amidoximinofurazan [43], 3-fluoro-5-(3-pyridinyloxy)-benzenamine and N- [46], eugenol and (+)-carvone [47], indapamide [48], and the explosives EDNH and DNTA [49].…”

Thermodynamic Studies of Two Different Inclusion Compounds with the Same Guest: Toward a General Understanding of Melting Behavior in Binary Compounds

“…Inclusion compoundsmulticomponent materials in which one component forms a host lattice in which other component(s) reside as guestsprovide an unusual opportunity to investigate structure−property relations, especially since their structures and intermolecular interactions can be modified in many ways. We have been studying inclusion compounds to add to the understanding of thermal properties of molecular solids, viz., thermal conductivity − and heat capacity and related lattice dynamical properties. − In addition, through examination of relative Gibbs energies of inclusion compounds and their pure components, we have been able to reach some general conclusions concerning melting behavior …”

1996 Noranda Award Lecture Thermal properties of solids: Étude in three-part anharmony

“…In this case the host molecule and clathrate are not isomorphous (space groups Pi and R3, respectively (12)), so direct comparisons are more difficult. For example, the higher thermal expansion and Gruneisen parameter of HPTB relative to HPTB.2CBr4 are not necessarily indicative of enhanced anharmonicity, as packing interactions will play an important role here (30). Nevertheless, our recent investigations of the thermal conductivity of HPTB.2CBr4 show it to be similar to THF clathrate hydrate and Dianin's compound, viz.…”