organic molecular crystals
Recently Published Documents


TOTAL DOCUMENTS

292
(FIVE YEARS 35)

H-INDEX

38
(FIVE YEARS 3)

2021 ◽  
Vol 8 (4) ◽  
pp. 20218411
Author(s):  
N. A. Zhestkij ◽  
E. V. Gunina ◽  
S. P. Fisenko ◽  
A. E. Rubtsov ◽  
D. A. Shipilovskikh ◽  
...  

The synthesis of (E)-2-((3-(ethoxycarbonyl)-5-methyl-4-phenylthiophen-2-yl)amino)-4-oxo-4-(p-tolyl)but-2-enoic acid was performed. This organic compound was used as a building block for the organic molecular crystals with highly stable photoluminescence at ambient conditions, which has been established during 10 years of exploitation.


2021 ◽  
Author(s):  
Shiyue Yang ◽  
Graeme Day

We describe the implementation of the Monte Carlo threshold algorithm for molecular crystals as a method to provide an estimate of the energy barriers separating crystal structures. By sampling the local energy minima accessible from multiple starting structures, the simulations yield a global picture of the crystal energy landscapes. This provides valuable information on the depth of the energy minima associated with crystal structures and adds to the information available from crystal structure prediction methods that are used for anticipating polymorphism. We present results from applying the threshold algorithm to four polymorphic organic molecular crystals, examine the influence of applying space group symmetry constraints during the simulations, and discuss the relationship between the structure of the energy landscape and the intermolecular interactions present in the crystals.


2021 ◽  
Vol 197 ◽  
pp. 110510
Author(s):  
Steven Monaco ◽  
Ryan P. Baer ◽  
Ryan P. Giernacky ◽  
Miguel E. Villalba ◽  
Taylor M. Garcia ◽  
...  

Author(s):  
Andrew D. Bond

Typical ranges of thermal expansion coefficients are established for organic molecular crystals in the Cambridge Structural Database. The CSD Python API is used to extract 6201 crystal structures determined close to room temperature and at least one lower temperature down to 90 K. The data set is dominated by structure families with only two temperature points and is subject to various sources of error, including incorrect temperature reporting and missing flags for variable-pressure studies. For structure families comprising four or more temperature points in the range 90–300 K, a linear relationship between unit-cell volume and temperature is shown to be a reasonable approximation. For a selected subset of 210 structures showing an optimal linear fit, the volumetric expansion coefficient at 298 K has mean 173 p.p.m. K−1 and standard deviation 47 p.p.m.  K−1. The full set of 6201 structures shows a similar distribution, which is fitted by a normal distribution with mean 161 p.p.m. K−1 and standard deviation 51 p.p.m. K−1, with excess population in the tails mainly comprising unreliable entries. The distribution of principal expansion coefficients, extracted under the assumption of a linear relationship between length and temperature, shows a positive skew and can be approximated by two half normal distributions centred on 33 p.p.m. K−1 with standard deviations 40 p.p.m. K−1 (lower side) and 56 p.p.m. K−1 (upper side). The distribution for the full structure set is comparable to that of the test subset, and the overall frequency of biaxial and uniaxial negative thermal expansion is estimated to be < 5% and ∼30%, respectively. A measure of the expansion anisotropy shows a positively skewed distribution, similar to the principal expansion coefficients themselves, and ranges based on suggested half normal distributions are shown to highlight literature cases of exceptional thermal expansion.


Author(s):  
Isaac Jerome C. Dela Cruz ◽  
Jem Valerie Perez ◽  
Bryan Gencianeo Alamani ◽  
Gerard Capellades ◽  
Allan S. Myerson

Author(s):  
M. Nozaki ◽  
M. Haniuda ◽  
K. Niki ◽  
T. Fujikawa ◽  
S. Kera

Author(s):  
Poonam Gupta ◽  
Suryanarayana Allu ◽  
Durga Prasad Karothu ◽  
Tamas Panda ◽  
Naba K. Nath

Sign in / Sign up

Export Citation Format

Share Document