Phase transitions in adamantane derivatives: 2-chloroadamantane

Paroli, Ralph M.; Kawai, Nancy T.; Butler, Ian S.; Gilson, D. F. R.

doi:10.1139/v88-318

Cited by 16 publications

(11 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the number of studies concerning 2-X-adamantane derivatives is less extensive, detailed polymorphic studies have also been reported. [15][16][17][18][19][20][21][22] The phase behavior of the 1-X adamantane compounds varies according to the substituent.…”

Section: Introductionmentioning

confidence: 99%

Phase Transition in Hydrogen-Bonded 1-Adamantane-methanol

Hassine

Négrier

Barrio

et al. 2015

Crystal Growth & Design

View full text Add to dashboard Cite

The polymorphism of 1-adamantane-methanol C 11 H 18 O has been investigated by differential thermal analysis and single-crystal and powder X-ray diffraction. Below the melting temperature (389.5 ± 0.4 K), this compound exhibits an orthorhombic phase (Phase I, Pnnm, Z=12, Z'=1.5). The melting enthalpy was determined to be 20.5 ± 0.4 kJ mol −1 , i.e.,with an entropy change of (6.34 ± 0.13)R, which is much higher than the quoted value fromTimmermans for the melting orientationally disordered phases (2.5R), thus supporting the orientationelly ordered character of phase I. This orthorhombic phase I exhibits a statistical disorder of the hydrogen atom related to the oxygen atom, due to the position of one independent molecule on the mirror. At ca. 272 K, phase I transforms continuously through an order-disorder transition to a low-temperature monoclinic phase II (P2 1 /n, Z=12, Z'=3). The monoclinic and orthorhombic phases are related by a group-subgroup relationship, which perfectly agrees with the continuous character of the II to I transition. Moreover, by a convenient choice of an order parameter related to the continuous tilt of the c-axis, the critical exponent for this transition is found to be close to the theoretical prediction of 3D-Ising model (with a critical exponent is of ca. 0.27).

show abstract

Section: Introductionmentioning

confidence: 99%

Phase Transition in Hydrogen-Bonded 1-Adamantane-methanol

Hassine

Négrier

Barrio

et al. 2015

Crystal Growth & Design

View full text Add to dashboard Cite

show abstract

“…The behaviour of fluoroadamantane under pressure also remains unexplored, and, due to the apparent disorder down to 4 K, the effect of pressure may be different from the effects that result from lowering the temperature. Thus, as an extension of previous studies on the chloro and bromo derivatives (17)(18)(19), the phase behaviour of fluoroadamantane was investigated by low-temperature and high-pressure vibrational spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Phase transitions in adamantane derivatives: 1-fluoroadamantane

Kawai¹,

Gilson²,

Butler³

1991

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

. Can. J. Chem. 69, 1758 (1991).The solid-state phase behaviour of 1-fluoroadamantane (1-CloH15F) has been investigated by differential scanning calorimetry, and by infrared and Rarnan spectroscopy. The phase transition occurs at 227 K on cooling and at 231 K upon heating, with average AHt and ASt of 1.65 kJ mol-' and 7.3 J K-' mol-l. The transition was also apparent in the low-temperature IR and Raman spectra by a sudden line narrowing, and characteristic spectral features of each phase were identified. Both phases I and I1 were disordered, and further cooling of phase I1 resulted in the formation of a glass. Attempts to induce a glass transition (predicted to occur at ~9 0 K) by slow heating were unsuccessful. Vibrational spectroscopic studies at high pressures showed a phase transition at 3.3 f 1.0 kbar, upon compression. The phases formed under pressure were the same as those induced by lowering temperature.

show abstract

“…Solid-state phase transitions of halogen-substituted adamantanes below the reference temperature 298.15 K has been a popular endeavor in the recent literature. Calorimetric studies of 1-Cl-adamantane [7,8], 2-Cl-adamantane [9,10], 1-Br-adamantane [7,[11][12][13], and 2-Br-adamantane [10] are already published in the literature and the available enthalpies of phase transitions are mostly in agreement within 1 kJ·mol -1 . In contrast, the solid-gas phase transitions of halogen-substituted adamantanes are reported only in three papers [11,[14][15] and reported sublimation enthalpies seem to be in disarray.…”

Section: Introductionmentioning

confidence: 91%