7Li and 14N NMR studies of phase II–III transition in LiNH4SO4 single crystals

2016 ◽  
Vol 247 ◽  
pp. 23-26
Author(s):  
Ae Ran Lim
Keyword(s):  
Phase Ii ◽  
1981 ◽  
Vol 45 (1-2) ◽  
pp. 167-188 ◽  
Author(s):  
S. Washburn ◽  
R. Schweizer ◽  
H. Meyer

1978 ◽  
Vol 33 (5) ◽  
pp. 515-520 ◽  
Author(s):  
K. Barlos ◽  
H. Nöth ◽  
B. Wrackmeyer

Abstract14N chemical shifts of a series of cyclic and noncyclic aminophosphines are reported. The nuclear shielding of nitrogen decreases with increasing number of halogen substituents at phosphorus as well as with increasing number of phosphinyl groups attached to nitrogen. In addition to the influence of electronegativity PN(π)-interactions may account for the observed shielding. Steric effects are discussed.


1977 ◽  
Vol 66 (12) ◽  
pp. 5433-5438 ◽  
Author(s):  
E. K. Wolff ◽  
R. G. Griffin ◽  
C. Watson

2015 ◽  
Vol 71 (6) ◽  
pp. 491-498 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Dmitrii M. Roitershtein ◽  
Ilya E. Nifant'ev ◽  
Ivan V. Ananyev ◽  
Tatyana V. Minyaeva ◽  
...  

(1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-1,3,5-triphenylcyclohexan-1-ol or (4-hydroxy-2,4,6-triphenylcyclohexane-1,3-diyl)bis(phenylmethanone), C38H32O3, (1), is formed as a by-product in the NaOH-catalyzed synthesis of 1,3,5-triphenylpentane-1,5-dione from acetophenone and benzaldehyde. Single crystals of the chloroform hemisolvate, C38H32O3·0.5CHCl3, were grown from chloroform. The structure has triclinic (P-1) symmetry. One diastereomer [as a pair of (1RS,2SR,3RS,4SR,5RS)-enantiomers] of (1) has been found in the crystal structure and confirmed by NMR studies. The dichoromethane hemisolvate has been reported previously [Zhanget al.(2007).Acta Cryst.E63, o4652]. (1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-3,5-bis(2-methoxyphenyl)-1-phenylcyclohexan-1-ol or [4-hydroxy-2,6-bis(2-methoxyphenyl)-4-phenylcyclohexane-1,3-diyl]bis(phenylmethanone), C40H36O5, (2), is also formed as a by-product, under the same conditions, from acetophenone and 2-methoxybenzaldehyde. Crystals of (2) have been grown from chloroform. The structure has orthorhombic (Pca21) symmetry. A diastereomer of (2) possesses the same configuration as (1). In both structures, the cyclohexane ring adopts a chair conformation with all bulky groups (benzoyl, phenyl and 2-methoxyphenyl) in equatorial positions. The molecules of (1) and (2) both display one intramolecular O—H...O hydrogen bond.


1985 ◽  
Vol 40 (3) ◽  
pp. 260-262 ◽  
Author(s):  
Th. Blümel ◽  
H. Stegemeyer

The growth of Blue Phase II liquid single crystals directly from the isotropic melt has been investigated in a mixed system of cholesteryl valerate and the nematogenic compound 8OBE by means of polarizing microscopy. Besides quadratic single crystals showing strong Bragg reflection additionally crystals of regular triangular habit with no detectable selective reflection have been found caused by the growth determining crystallographic form {111}.


1996 ◽  
Vol 51 (5-6) ◽  
pp. 761-768 ◽  
Author(s):  
H. Honda ◽  
M. Kenmotsu ◽  
N. Onoda-Yamamuro ◽  
H. Ohki ◽  
S. Ishimaru ◽  
...  

The temperature dependence of the 15N and 133Cs NMR spin-lattice relaxation times, the 15N spin-spin relaxation time, and the 15N and 133Cs spectra of CsNO2 was observed in the plastic phase (209.2 < T < 673 K (m. p.)) and the low-temperature phase (Phase II). In Phase II we found the NO-2 180°-flip, which could be attributed to the anomalous increase of the heat capacity curve, and determined the activation energy of this motion to be 8.7-11.7 kJ mol-1. The 15N and 133Cs spectra in this phase are inconsistent with the reported crystal structure R3̅m and can be explained by lower crystal symmetry. In the plastic phase we detected a new anionic motion with 11 kJ mol-1 , an isotropic NO-2 reorientation with 8.5-9 kJ mol-1, and ionic self-diffusion with 47 kJ mol-1. The presence of ionic self-diffusion was confirmed by measuring the electrical conductivity.


ChemInform ◽  
2010 ◽  
Vol 23 (10) ◽  
pp. no-no
Author(s):  
P. J. BAILEY ◽  
G. C. CONOLE ◽  
B. F. G. JOHNSON ◽  
J. LEWIS ◽  
M. MCPARTLIN ◽  
...  

2000 ◽  
Vol 55 (11-12) ◽  
pp. 891-894 ◽  
Author(s):  
Z. Czapla ◽  
S. Dacko ◽  
B. Kosturek

Abstract Single crystals of pyridinium periodate were grown, and their physical properties were studied. Anomalies of the electric permittivity and birefringence were observed at TC1 = 321 K and TC2 = 211 K. These observations gave evidences for the existence of three phases denoted as I, II, and III. Hysteresis loops were observed both in phase II and III. Pyroelectric measurements showed two anomalies at TC1 and TC2 . The anomaly at TC1 is related to the transition between a para-and ferroelectric phase, and the anomaly at T cl to the transition between two ferroelectric phases.


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