In Situ Tailor-Made Additives for Molecular Crystals: A Simple Route to Morphological Crystal Engineering

2016 ◽  
Vol 16 (7) ◽  
pp. 3555-3561 ◽  
Author(s):  
Seung-Heon Lee ◽  
Gyeong-Hui Lee ◽  
Kang-Hyun Lee ◽  
Mojca Jazbinsek ◽  
Bong Joo Kang ◽  
...  
Keyword(s):  
Crystal Engineering ◽  
Molecular Crystals ◽  
Simple Route

In situ nanoscale visualization of solvent effects on molecular crystal surfaces

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mikkel Herzberg ◽  
Anders Støttrup Larsen ◽  
Tue Hassenkam ◽  
Anders Østergaard Madsen ◽  
Jukka Rantanen
Keyword(s):  
Solid Solution ◽  
Solvent Effects ◽  
Molecular Crystal ◽  
Rational Design ◽  
Molecular Level ◽  
Molecular Crystals ◽  
Crystal Surfaces ◽  
Solution Interface ◽  
Atomic Force

Solvents can dramatically affect molecular crystals. Obtaining favorable properties for these crystals requires rational design based on molecular level understanding of the solid-solution interface. Here we show how atomic force...

scholarly journals Two-dimensional inorganic molecular crystals

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Wei Han ◽  
Pu Huang ◽  
Liang Li ◽  
Fakun Wang ◽  
Peng Luo ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Electronic Devices ◽  
Molecular Crystals ◽  
High Energy ◽  
Two Dimensional ◽  
Β Phase ◽  
Α Phase ◽  
Growth Plane ◽  
Transmission Electron

Abstract Two-dimensional molecular crystals, consisting of zero-dimensional molecules, are very appealing due to their novel physical properties. However, they are mostly limited to organic molecules. The synthesis of inorganic version of two-dimensional molecular crystals is still a challenge due to the difficulties in controlling the crystal phase and growth plane. Here, we design a passivator-assisted vapor deposition method for the growth of two-dimensional Sb2O3 inorganic molecular crystals as thin as monolayer. The passivator can prevent the heterophase nucleation and suppress the growth of low-energy planes, and enable the molecule-by-molecule lateral growth along high-energy planes. Using Raman spectroscopy and in situ transmission electron microscopy, we show that the insulating α-phase of Sb2O3 flakes can be transformed into semiconducting β-phase under heat and electron-beam irradiation. Our findings can be extended to the controlled growth of other two-dimensional inorganic molecular crystals and open up opportunities for potential molecular electronic devices.

Midway between Energetic Molecular Crystals and High-Density Energetic Salts: Crystal Engineering with Hydrogen Bonded Chains of Polynitro Bipyrazoles

2020 ◽  
Vol 20 (2) ◽  
pp. 755-764 ◽  
Author(s):  
Ivan Gospodinov ◽  
Kostiantyn V. Domasevitch ◽  
Cornelia C. Unger ◽  
Thomas M. Klapötke ◽  
Jörg Stierstorfer
Keyword(s):  
Crystal Engineering ◽  
Molecular Crystals ◽  
High Density ◽  
Energetic Salts ◽  
Hydrogen Bonded

Associations of squaric acid and its anions as multiform building blocks of hydrogen-bonded molecular crystals

2001 ◽  
Vol 57 (6) ◽  
pp. 859-865 ◽  
Author(s):  
Gastone Gilli ◽  
Valerio Bertolasi ◽  
Paola Gilli ◽  
Valeria Ferretti
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Negative Charge ◽  
Three Dimensional ◽  
Molecular Crystals ◽  
Building Blocks ◽  
Squaric Acid ◽  
Orthosilicic Acid ◽  
Molecular Plane ◽  
Dimensional Crystal

Squaric acid, H2C4O4 (H2SQ), is a completely flat diprotic acid that can crystallize as such, as well as in three different anionic forms, i.e. H2SQ·HSQ−, HSQ− and SQ2−. Its interest for crystal engineering studies arises from three notable factors: (i) its ability of donating and accepting hydrogen bonds strictly confined to the molecular plane; (ii) the remarkable strength of the O—H...O bonds it may form with itself which are either of resonance-assisted (RAHB) or negative-charge-assisted [(−)CAHB] types; (iii) the ease with which it may donate a proton to an aromatic base which, in turn, back-links to the anion by strong low-barrier N—H+...O1/2− charge-assisted hydrogen bonds. Analysis of all the structures so far known shows that, while H2SQ can only crystallize in an extended RAHB-linked planar arrangement and SQ2− tends to behave much as a monomeric dianion, the monoanion HSQ− displays a number of different supramolecular patterns that are classifiable as β-chains, α-chains, α-dimers and α-tetramers. Partial protonation of these motifs leads to H2SQ·HSQ− anions whose supramolecular patterns include ribbons of dimerized β-chains and chains of emiprotonated α-dimers. The topological similarities between the three-dimensional crystal chemistry of orthosilicic acid, H4SiO4, and the two-dimensional one of squaric acid, H2C4O4, are finally stressed.

scholarly journals Origin and structure of polar domains in doped molecular crystals

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
E. Meirzadeh ◽  
I. Azuri ◽  
Y. Qi ◽  
D. Ehre ◽  
A. M. Rappe ◽  
...  
Keyword(s):  
Crystal Engineering ◽  
Density Functional ◽  
Molecular Crystals ◽  
Strong Support ◽  
Functional Theory ◽  
Guest Molecules ◽  
Molecular Dynamics Calculations ◽  
Different Temperatures ◽  
Global Understanding

Abstract Doping is a primary tool for the modification of the properties of materials. Occlusion of guest molecules in crystals generally reduces their symmetry by the creation of polar domains, which engender polarization and pyroelectricity in the doped crystals. Here we describe a molecular-level determination of the structure of such polar domains, as created by low dopant concentrations (<0.5%). The approach comprises crystal engineering and pyroelectric measurements, together with dispersion-corrected density functional theory and classical molecular dynamics calculations of the doped crystals, using neutron diffraction data of the host at different temperatures. This approach is illustrated using centrosymmetric α-glycine crystals doped with minute amounts of different L-amino acids. The experimentally determined pyroelectric coefficients are explained by the structure and polarization calculations, thus providing strong support for the local and global understanding of how different dopants influence the properties of molecular crystals.

scholarly journals Plasticity in zwitterionic drugs: the bending properties of Pregabalin and Gabapentin and their hydrates

IUCrJ ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 630-634 ◽  
Author(s):  
U. B. Rao Khandavilli ◽  
Matteo Lusi ◽  
Patrick J. Frawley
Keyword(s):  
Mechanical Properties ◽  
Crystal Engineering ◽  
Weak Interactions ◽  
Molecular Crystals ◽  
Structural Features ◽  
Microscopic Structure ◽  
Bending Properties ◽  
Crystalline Materials ◽  
Area Of Interest ◽  
Macroscopic Plasticity

The investigation of mechanical properties in molecular crystals is emerging as a novel area of interest in crystal engineering. Indeed, good mechanical properties are required to manufacture pharmaceutical and technologically relevant substances into usable products. In such endeavour, bendable single crystals help to correlate microscopic structure to macroscopic properties for potential design. The hydrate forms of two anticonvulsant zwitterionic drugs, Pregabalin and Gabapentin, are two examples of crystalline materials that show macroscopic plasticity. The direct comparison of these structures with those of their anhydrous counterparts, which are brittle, suggests that the presence of water is critical for plasticity. In contrast, structural features such as molecular packing and anisotropic distribution of strong and weak interactions seem less important.

scholarly journals In Situ Assessment of Intrinsic Strength of X-I⋯OA-Type Halogen Bonds in Molecular Crystals with Periodic Local Vibrational Mode Theory

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1589 ◽  
Author(s):  
Yunwen Tao ◽  
Yue Qiu ◽  
Wenli Zou ◽  
Sadisha Nanayakkara ◽  
Seth Yannacone ◽  
...  
Keyword(s):  
Bond Strength ◽  
Vibrational Mode ◽  
Halogen Bond ◽  
Molecular Crystals ◽  
Halogen Bonding ◽  
Halogen Bonds ◽  
Mode Theory ◽  
Local Vibrational Mode ◽  
Intrinsic Strength

Periodic local vibrational modes were calculated with the rev-vdW-DF2 density functional to quantify the intrinsic strength of the X-I⋯OA-type halogen bonding (X = I or Cl; OA: carbonyl, ether and N-oxide groups) in 32 model systems originating from 20 molecular crystals. We found that the halogen bonding between the donor dihalogen X-I and the wide collection of acceptor molecules OA features considerable variations of the local stretching force constants (0.1–0.8 mdyn/Å) for I⋯O halogen bonds, demonstrating its powerful tunability in bond strength. Strong correlations between bond length and local stretching force constant were observed in crystals for both the donor X-I bonds and I⋯O halogen bonds, extending for the first time the generalized Badger’s rule to crystals. It is demonstrated that the halogen atom X controlling the electrostatic attraction between the σ -hole on atom I and the acceptor atom O dominates the intrinsic strength of I⋯O halogen bonds. Different oxygen-containing acceptor molecules OA and even subtle changes induced by substituents can tweak the n → σ ∗ (X-I) charge transfer character, which is the second important factor determining the I⋯O bond strength. In addition, the presence of the second halogen bond with atom X of the donor X-I bond in crystals can substantially weaken the target I⋯O halogen bond. In summary, this study performing the in situ measurement of halogen bonding strength in crystalline structures demonstrates the vast potential of the periodic local vibrational mode theory for characterizing and understanding non-covalent interactions in materials.

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