Structural Definition of the Low-Temperature Phase Transition of Tris(ethane-1,2-diamine)zinc(II) Dinitrate

2003 ◽  
Vol 56 (4) ◽  
pp. 287 ◽  
Author(s):  
Paul V. Bernhardt ◽  
Mark J. Riley
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Complex Cation ◽  
Spectroscopic Studies ◽  
Temperature Phase ◽  
Temperature Structure ◽  
Reversible Phase Transition ◽  
Temperature Phase Transition ◽  
Definition Of ◽  
Low Temperature Phase

The 93 K X-ray crystal structure of tris(ethane-1,2-diamine)zinc(II) dinitrate is reported. As predicted by the spectroscopic studies of other workers, there is a reversible phase transition of the structure at low temperature. We have determined this temperature to be 143 K. The structure at this temperature and below resembles that of the room temperature structure, except the crystallographic D3 symmetry of the complex cation (296 K) is lowered to C2 (below 144 K) by subtle changes in cation–anion hydrogen bonding. No change in the conformation of the cation or its bond lengths and angles was found.

Possible low-temperature phase transition of Langmuir–Blodgett films of a charge–transfer complex detected by ESR

1998 ◽  
Vol 327-329 ◽  
pp. 391-394
Author(s):  
Keiichi Ikegami ◽  
Shin-ichi Kuroda ◽  
Tomoyuki Akutagawa ◽  
Taro Konuma ◽  
Takayoshi Nakamura ◽  
...  
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Low Temperature ◽  
Charge Transfer Complex ◽  
Temperature Phase ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films ◽  
Temperature Phase Transition ◽  
A Charge ◽  
Low Temperature Phase

Low‐Temperature Phase Transition of Vanadium Sesquioxide

1970 ◽  
Vol 41 (2) ◽  
pp. 836-838 ◽  
Author(s):  
Mitsuoki Nakahira ◽  
Shigeo Horiuchi ◽  
Hirotoshi Ooshima
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Temperature Phase ◽  
Vanadium Sesquioxide ◽  
Temperature Phase Transition ◽  
Low Temperature Phase

scholarly journals Phase transition and proton ordering at 50 K in 3-(pyridin-4-yl)pentane-2,4-dione

2017 ◽  
Vol 73 (6) ◽  
pp. 1172-1178 ◽  
Author(s):  
Khai-Nghi Truong ◽  
Carina Merkens ◽  
Martin Meven ◽  
Björn Faßbänder ◽  
Richard Dronskowski ◽  
...  
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Single Crystal ◽  
Structural Phase ◽  
Pyridyl Ring ◽  
Temperature Phase ◽  
Crystallographic Axis ◽  
Temperature Phase Transition ◽  
Intramolecular Hydrogen ◽  
Low Temperature Phase

Single-crystal neutron diffraction experiments at 100 and 2.5 K have been performed to determine the structure of 3-(pyridin-4-yl)pentane-2,4-dione (HacacPy) with respect to its protonation pattern and to monitor a low-temperature phase transition. Solid HacacPy exists as the enol tautomer with a short intramolecular hydrogen bond. At 100 K, its donor···acceptor distance is 2.450 (8) Å and the compound adopts space group C2/c, with the N and para-C atoms of the pyridyl ring and the central C of the acetylacetone substituent on the twofold crystallographic axis. As a consequence of the axial symmetry, the bridging hydrogen is disordered over two symmetrically equivalent positions, and the carbon–oxygen bond distances adopt intermediate values between single and double bonds. Upon cooling, a structural phase transition to the t 2 subgroup P\bar 1 occurs; the resulting twins show an ordered acetylacetone moiety. The phase transition is fully reversible but associated with an appreciable hysteresis in the large single crystal under study: transition to the low-temperature phase requires several hours at 2.5 K and heating to 80 K is required to revert the transformation. No significant hysteresis is observed in a powder sample, in agreement with the second-order nature of the phase transition.

Low-Temperature Phase Transition Detected by ESR in α′-(BEDT-TTF)2IBr2 Single Crystals

2011 ◽  
Vol 41 (2-4) ◽  
pp. 363-370
Author(s):  
Alisa Chernenkaya ◽  
Marina Kirman ◽  
Alexei Dmitriev ◽  
Roman Morgunov ◽  
Oksana Koplak ◽  
...  
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Single Crystals ◽  
Temperature Phase ◽  
Temperature Phase Transition ◽  
Low Temperature Phase

Low temperature phase transition in NaOD

1986 ◽  
Vol 57 (5) ◽  
pp. 339-341 ◽  
Author(s):  
T.J. Bastow ◽  
M.M. Elcombe ◽  
C.J. Howard
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Temperature Phase ◽  
Temperature Phase Transition ◽  
Low Temperature Phase
Sign in / Sign up

Export Citation Format

Share Document