The crystal structure and thermal expansion of the CCl₄ adduct of Dianin's compound

Abstract

. 68, 1352 (1990).The crystal structure of the title compound has been determined by single cry_stal X-ray diffraction data collected at 293 K, and refined to a final R,, of 0.057. The crystals are rhombohedral, space group R3, with a = 27.134(8) A, c = 10.933(2) A, and Z = 18. The mole ratio of Dianin's compound (4-p-hydroxyphenyl-2,2,4-trimethylchroma) to CCI, is 6: 1. The guest molecules are disordered. X-ray powder diffraction was carried out in the temperature range from 10 to 300 K. From this, the thermal expansion coefficients for the a-and c-axes and the volume have been determined.

Crystal structure and thermal expansion of hexakis(phenylthio)benzene and its CBr4 clathrate

“…6) with slightly higher values for pure HPTB. This contrasts with results for clathrate hydrates and Dianin's clathrates, which showed enhanced thermal expansion of the clathrates with respect to the host compound (i.e., ice or the clathrand of Dianin's compound) (9,10,28,29). This was ascribed to the extra pressure exerted by the host molecules on the walls of the cages; molecular dynamics simulations corroborated this view for clathrate hydrates (28).…”

“…We have initiated investigations of thermal properties of clathrates to get insight into the aforementioned aspects of molecular behaviour (5)(6)(7)(8)(9)(10)(11)(12). Thermal expansion is one of these properties.…”

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

“…In light of the present emphasis, we draw attention to the slight increase in thermal expansion with mobile ethanol guests, relative to the clathrand and the clathrate with the less mobile CCI, molecules as guests (see Fig. 2) (24,26). However, the effect of the guest on the volume Griineisen parameter is that y, is enhanced almost equally for ethanol and CCl, guests (27); see Fig.…”

“…3. (Of course a and y are both anisotropic, and we have studied their directional dependences (24,26,27) but it does not resolve this apparent contradiction. )…”

Thermal Properties and Transition Behavior of Host-Guest Compounds Under High Pressure

“…Dianin's compound can accommodate numerous guest molecules such as CCl 4 [79] and ethanol [80], and the guest-free compound crystallizes in the trigonal space group 3 with a= 26.965 Å and c= 10.933 Å [81]. In a recent comprehensive structural study, Lee et al [82] have reported the structure of 18 of its clathrates, as well as data on the location, orientation and dynamics of the guests in the host cavity.…”