Phase transitions involving re-ordering of the guest molecules in a solid organic inclusion compound: heptanoic anhydride–urea

1995 ◽  
pp. 2341-2342 ◽  
Author(s):  
Ian J. Shannon ◽  
Kenneth D. M. Harris ◽  
François Guillaume ◽  
Eduardo H. Bocanegra ◽  
Elizabeth J. MaClean
Keyword(s):  
Phase Transitions ◽  
Inclusion Compound ◽  
Guest Molecules ◽  
Organic Inclusion

Molecular dynamics of guest molecules in the cyclohexane/thiourea inclusion compound: a combined MD-IQNS study

1997 ◽  
Vol 241-243 ◽  
pp. 472-474 ◽  
Author(s):  
Matthew J Jones ◽  
Stéphanie Camus ◽  
François Guillaume ◽  
Kenneth D.M Harris ◽  
Albert-José Dianoux
Keyword(s):  
Molecular Dynamics ◽  
Inclusion Compound ◽  
Guest Molecules ◽  
Compound A

Temperature-dependent structural properties of a solid urea inclusion compound containing chiral guest molecules: 2-bromotetradecane/urea

1999 ◽  
Vol 77 (12) ◽  
pp. 2105-2118 ◽  
Author(s):  
Lily Yeo ◽  
Kenneth DM Harris
Keyword(s):  
High Temperature ◽  
Structural Properties ◽  
Inclusion Compound ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Tunnel Structure ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
Urea Inclusion Compound ◽  
Urea Inclusion

Periodic structural properties of the 2-bromotetradecane/urea inclusion compound have been investigated as a function of temperature. Differential scanning calorimetry between 298 and 98 K identified three well-defined regimes, denoted the high-, intermediate-, and low-temperature phases. The structural properties of each phase (at 293, 207, and 142 K, respectively) have been investigated by single crystal X-ray diffraction. In the high-temperature phase, the inclusion compound has the hexagonal urea tunnel structure (P6122) characteristic of the conventional urea inclusion compounds, with substantial orientational disorder of the guest molecules. In the intermediate-temperature phase, the symmetry is lowered to orthorhombic (C2221), although the host structure remains close to the hexagonal tunnel structure of the high-temperature phase and there is no clear evidence for increased orientational ordering of the guest molecules. In the low-temperature phase, the urea tunnel structure is monoclinic (P21), and is based on a 2 × 2 × 1 supercell of the hexagonal cell of the high-temperature structure. There are four independent types of tunnel, three of which are strongly distorted from hexagonal geometry. Within these distorted tunnels, there is a comparatively narrow distribution of guest molecule orientations, which correlate well with the observed distortions of the tunnels. The 2-bromotetradecane/urea inclusion compound highlights several issues of wider relevance concerning the structural properties of solid inclusion compounds.Key words: urea inclusion compounds, X-ray diffraction, phase transitions, chiral recognition, incommensurate solid, 2-bromotetradecane/urea.

Molecular dynamics simulation study of cyclohexane guest molecules in the cyclohexane/thiourea inclusion compound

2000 ◽  
Vol 261 (1-2) ◽  
pp. 125-135 ◽  
Author(s):  
Jean-Christophe Soetens ◽  
Arnaud Desmedt ◽  
François Guillaume ◽  
Kenneth D.M. Harris
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Simulation Study ◽  
Inclusion Compound ◽  
Dynamics Simulation ◽  
Guest Molecules

Probing Time Dependent Phase Transformation in a Flexible Metal-Organic Framework with Nanoindentation

2021 ◽  
Author(s):  
Prakash Kanoo ◽  
Manish Kumar Mishra ◽  
Arpan Hazra
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Room Temperature ◽  
Metal Organic Framework ◽  
Time Dependent ◽  
Guest Molecules ◽  
Nanoindentation Technique ◽  
Metal Organic ◽  
Flexible Metal ◽  
Organic Framework

Phase transformation in a flexible metal-organic framework, {[Zn4(1,4-NDC)4(1,2-BPE)2]•xSolvent}n, which loses guest molecules rapidly at room temperature, leading to several phase transitions, is examined using nanoindentation technique. Nanoindentation results reveal time...

Investigation of the Phase Transition at 67.17 K in the Thiourea-CCl4 Inclusion Compound. As Studied by 14N NQR

1994 ◽  
Vol 49 (1-2) ◽  
pp. 433-438 ◽  
Author(s):  
J. El Ghallali ◽  
M. Gourdji ◽  
L. Guibé ◽  
A. Péneau
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Carbon Tetrachloride ◽  
Inclusion Compound ◽  
Central Line ◽  
Host Lattice ◽  
Central Component ◽  
Two Phase ◽  
Temperature Range ◽  
Calorimetric Measurements

Abstract The 14N NQR from the host lattice of the thiourea-carbon tetrachloride inclusion compound. From calorimetric measurements, two phase transitions are known to occur at 67.2 K and 41.3 K in this compound. Above the 67.2 K transition, the 14N NQR spectrum consists of one resonance, though a small splitting of about 0.5 kHz is seen at temperatures up to ca. 105 K. Below the transition, the resonance appears as a central component, in continuation of the resonance above the transition, and two satellites at + 10 kHz and -8 kHz from the central line. The transition from the single resonance to a fully resolved spectrum takes place in a temperature range of less than one kelvin. The results are compared with those previously obtained with the thiourea-cyclohexane inclusion compound.

Sign in / Sign up

Export Citation Format

Share Document