Polar Order by Rational Design:  Crystal Engineering with Parallel Beloamphiphile Monolayers†

2007 ◽  
Vol 40 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Rainer Glaser
Keyword(s):  
Crystal Engineering ◽  
Rational Design ◽  
Polar Order

Sulfur as hydrogen-bond acceptor in cocrystals of 2-thio-modified thymine

2018 ◽  
Vol 74 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Engineering ◽  
Rational Design ◽  
Three Dimensional ◽  
Good Reliability ◽  
Hydrogen Bond Acceptor ◽  
Hydrogen Bonding Interactions ◽  
Hydrogen Bonding Site ◽  
Hydrogen Bonded

Doubly and triply hydrogen-bonded supramolecular synthons are of particular interest for the rational design of crystal and cocrystal structures in crystal engineering since they show a high robustness due to their high stability and good reliability. The compound 5-methyl-2-thiouracil (2-thiothymine) contains an ADA hydrogen-bonding site (A = acceptor and D = donor) if the S atom is considered as an acceptor. We report herein the results of cocrystallization experiments with the coformers 2,4-diaminopyrimidine, 2,4-diamino-6-phenyl-1,3,5-triazine, 6-amino-3H-isocytosine and melamine, which contain complementary DAD hydrogen-bonding sites and, therefore, should be capable of forming a mixed ADA–DAD N—H...S/N—H...N/N—H...O synthon (denoted synthon 3s N·S;N·N;N·O), consisting of three different hydrogen bonds with 5-methyl-2-thiouracil. The experiments yielded one cocrystal and five solvated cocrystals, namely 5-methyl-2-thiouracil–2,4-diaminopyrimidine (1/2), C5H6N2OS·2C4H6N4, (I), 5-methyl-2-thiouracil–2,4-diaminopyrimidine–N,N-dimethylformamide (2/2/1), 2C5H6N2OS·2C4H6N4·C3H7NO, (II), 5-methyl-2-thiouracil–2,4-diamino-6-phenyl-1,3,5-triazine–N,N-dimethylformamide (2/2/1), 2C5H6N2OS·2C9H9N5·C3H7NO, (III), 5-methyl-2-thiouracil–6-amino-3H-isocytosine–N,N-dimethylformamide (2/2/1), (IV), 2C5H6N2OS·2C4H6N4O·C3H7NO, (IV), 5-methyl-2-thiouracil–6-amino-3H-isocytosine–N,N-dimethylacetamide (2/2/1), 2C5H6N2OS·2C4H6N4O·C4H9NO, (V), and 5-methyl-2-thiouracil–melamine (3/2), 3C5H6N2OS·2C3H6N6, (VI). Synthon 3s N·S;N·N;N·O was formed in three structures in which two-dimensional hydrogen-bonded networks are observed, while doubly hydrogen-bonded interactions were formed instead in the remaining three cocrystals whereby three-dimensional networks are preferred. As desired, the S atoms are involved in hydrogen-bonding interactions in all six structures, thus illustrating the ability of sulfur to act as a hydrogen-bond acceptor and, therefore, its value for application in crystal engineering.

scholarly journals Design of Mechanically Flexible Organic Crystals: A Crystal Engineering Approach

2014 ◽  
Vol 70 (a1) ◽  
pp. C648-C648
Author(s):  
Gamidi Krishna ◽  
Ramesh Devarapalli ◽  
Garima Lal ◽  
C. Reddy
Keyword(s):  
Crystal Structures ◽  
Organic Solar Cells ◽  
Crystal Engineering ◽  
Rational Design ◽  
Organic Materials ◽  
Building Blocks ◽  
Design Strategy ◽  
High Plasticity ◽  
Simple Strategy ◽  
Slip Planes

Utilization of organic single crystal materials is increasing day by day owing to their promising applications in organic light emitting diodes [1], organic solar cells, mechanochromic luminescence [2] and tablatability [3] of APIs etc. These desirable functions, especially mechanical properties, can be achieved by imparting soft nature in organic materials, however unfortunately there is no simple strategy to attain this. Till date all the findings are serendipitous discoveries, so a rational design strategy is necessary to accomplish such soft mechanical behavior in molecular crystals. Here we propose a design strategy to attain plastically deformable organic materials by introducing slip planes in the crystal structures. The high plasticity can be achieved by introducing hydrophobic groups, such as t-Bu, -OMe, -Me and multiple –Cl (or) –Br groups on -Ar building blocks, for example on naphthalene diimide (NDI), which leads to the formation of slip planes in the crystal structures (as shown in attached figure), hence facilitate the plastic (irreversible) bending [2].

scholarly journals Improving Hydride Conductivity in Layered Perovskites via Crystal Engineering

2020 ◽  
Author(s):  
Harry W. T. Morgan ◽  
Harry J. Stroud ◽  
Neil Allan
Keyword(s):  
Crystal Engineering ◽  
Density Functional ◽  
Rational Design ◽  
Ionic Mobility ◽  
Theory Approach ◽  
Ion Migration ◽  
Energy Applications ◽  
Migration Pathway ◽  
Migration Pathways ◽  
Layered Perovskites

Hydride ion conduction in layered perovskites is of great interest for sustainable-energy applications. In this report we study Ba2ScHO3, a recently synthesized oxyhydride with an unusual anion ordering, using a multifaceted density functional theory approach involving both transition state calculations and molecular dynamics simulations. Beyond simply identifying the key ion migration pathways, we perform detailed analysis of transition states and identify key interactions which drive trends in ionic mobility. Our key findings are that ionic mobility is, remarkably, independent of hydride-oxide disorder, the dominant migration pathway changes under pressure, and a reduction in A-site cation size accelerates hydride diffusion. Local structural flexibility along migration pathways is understood in terms of dimensionality and ionic size, and we thus identify crystal engineering principles for rational design of ion conductors. On the basis of our new insights into these materials, we predict that Sr2ScHO3 will show improved conductivity over existing analogues.

scholarly journals New Ag(I) Coordination Complexes Based on Bis(1-isoquinolinecarboxamide)ethane.

2014 ◽  
Vol 70 (a1) ◽  
pp. C665-C665
Author(s):  
Nicole Parra ◽  
Julio Belmar ◽  
Claudio Jiménez ◽  
Jorge Pasán ◽  
Catalina Ruiz-Pérez
Keyword(s):  
Crystal Engineering ◽  
Rational Design ◽  
Crystal Packing ◽  
Functional Materials ◽  
Coordination Complexes ◽  
Intermolecular Forces ◽  
Research Area ◽  
Molecular Structures ◽  
Gauche Conformation ◽  
Design And Synthesis

Crystal Engineering is an interdisciplinary research area that involves chemists, physicists, biologists and materials scientists.1It is an important field inside Supramolecular Chemistry which has been considered as a new form of synthesis, named Supramolecular Synthesis.2It is known that important properties in molecular solids are closely related with the way that molecules are aggregated in the condensed phase. Consequently, the ability to control the molecular association in the crystal packing could offer control over specific properties and potential applications. Because of that, the main goal of Crystal Engineering is the rational design and synthesis of functional materials using the nature of the intermolecular forces as a toolkit. Our strategy is the systematic study of non-covalent forces in homologous series.3In this work our interest is focused on the study of crystal packing of two homologous ligands N,N'-bis(1-isoquinolinecarboxamide)-1,2-ethane (1) and N,N'-dimethyl-N,N'-bis(1-isoquinolinecarboxamide)-1,2-ethane (2) and their Ag(I) coordination complexes. The compound 1 consists of two isoquinoline rings and one ethylene bridge linked by amide functional groups. Compound 2 is the result of the N-methylation of 1. The main difference in the molecular structures is that while 1 present a gauche conformation in the 1,2-ethanediamine bridge (600) 2 present a staggered conformation (1800). Curiously, in spite of this fact, the Ag(I) complexes in both cases present a small torsion angle of 4501-Ag(I) and 6502-Ag(I). These orientations allow the torsion of the isoquinoline moiety and the formation of homonuclear 0D coordination complexes, over the 1D coordination polymer expected. The main intermolecular interaction in 1 is the amide-to-amide hydrogen bond that is replaced by a weak CH··O interaction in 2 On the other hand, both Ag(I) complexes use the nitrate counteranion to build a chain using NH··O(nitrate) in 1 and CH(quinoline)··O(nitrate) in 2.Acknowledgment: Grant DIUC 212.023.049-1.0

6-Propyl-2-thiouracilversus6-methoxymethyl-2-thiouracil: enhancing the hydrogen-bonded synthon motif by replacement of a methylene group with an O atom

2016 ◽  
Vol 72 (8) ◽  
pp. 634-646 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Ernst Egert ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Engineering ◽  
Rational Design ◽  
Antithyroid Drug ◽  
Chemical Properties ◽  
Structural Similarity ◽  
Molecular Solids ◽  
Hydrogen Bond Acceptor ◽  
Methylene Group

The understanding of intermolecular interactions is a key objective of crystal engineering in order to exploit the derived knowledge for the rational design of new molecular solids with tailored physical and chemical properties. The tools and theories of crystal engineering are indispensable for the rational design of (pharmaceutical) cocrystals. The results of cocrystallization experiments of the antithyroid drug 6-propyl-2-thiouracil (PTU) with 2,4-diaminopyrimidine (DAPY), and of 6-methoxymethyl-2-thiouracil (MOMTU) with DAPY and 2,4,6-triaminopyrimidine (TAPY), respectively, are reported. PTU and MOMTU show a high structural similarity and differ only in the replacement of a methylene group (–CH2–) with an O atom in the side chain, thus introducing an additional hydrogen-bond acceptor in MOMTU. Both molecules contain anADAhydrogen-bonding site (A= acceptor andD= donor), while the coformers DAPY and TAPY both show complementaryDADsites and therefore should be capable of forming a mixedADA/DADsynthon with each other,i.e. N—H...O, N—H...N and N—H...S hydrogen bonds. The experiments yielded one solvated cocrystal salt of PTU with DAPY, four different solvates of MOMTU, one ionic cocrystal of MOMTU with DAPY and one cocrystal salt of MOMTU with TAPY, namely 2,4-diaminopyrimidinium 6-propyl-2-thiouracilate–2,4-diaminopyrimidine–N,N-dimethylacetamide–water (1/1/1/1) (the systematic name for 6-propyl-2-thiouracilate is 6-oxo-4-propyl-2-sulfanylidene-1,2,3,6-tetrahydropyrimidin-1-ide), C4H7N4+·C7H9N2OS−·C4H6N4·C4H9NO·H2O, (I), 6-methoxymethyl-2-thiouracil–N,N-dimethylformamide (1/1), C6H8N2O2S·C3H7NO, (II), 6-methoxymethyl-2-thiouracil–N,N-dimethylacetamide (1/1), C6H8N2O2S·C4H9NO, (III), 6-methoxymethyl-2-thiouracil–dimethyl sulfoxide (1/1), C6H8N2O2S·C2H6OS, (IV), 6-methoxymethyl-2-thiouracil–1-methylpyrrolidin-2-one (1/1), C6H8N2O2S·C5H9NO, (V), 2,4-diaminopyrimidinium 6-methoxymethyl-2-thiouracilate (the systematic name for 6-methoxymethyl-2-thiouracilate is 4-methoxymethyl-6-oxo-2-sulfanylidene-1,2,3,6-tetrahydropyrimidin-1-ide), C4H7N4+·C6H7N2O2S−, (VI), and 2,4,6-triaminopyrimidinium 6-methoxymethyl-2-thiouracilate–6-methoxymethyl-2-thiouracil (1/1), C4H8N5+·C6H7N2O2S−·C6H8N2O2S, (VII). Whereas in (I) only anAA/DDhydrogen-bonding interaction was formed, the structures of (VI) and (VII) both display the desiredADA/DADsynthon. Conformational studies on the side chains of PTU and MOMTU also revealed a significant deviation for cocrystals (VI) and (VII), leading to the desired enhancement of the hydrogen-bond pattern within the crystal.

Noncentrosymmetry in Mixed Metal Oxide-Fluorides, Can We Control It?

2008 ◽  
Vol 1148 ◽  
Author(s):  
Rachelle Ann F. Pinlac ◽  
Michael R. Marvel ◽  
Julien J.-M. Lesage ◽  
Kenneth R. Poeppelmeier
Keyword(s):  
Crystal Structure ◽  
Crystal Engineering ◽  
Rational Design ◽  
Crystal Structure Analysis ◽  
Mixed Metal Oxide ◽  
Polar Structure ◽  
Chiral Structures ◽  
Jahn Teller ◽  
Cation Coordination ◽  
Oxide Ions

AbstractThe rational design of crystal structures, in particular noncentrosymmetric materials, and how to differentiate polar, polar-chiral, and chiral structures, is an ongoing theme in crystal engineering. In KNaNbOF5, the combination of a second-order Jahn Teller active d0 transition metal oxyfluoride anionic unit and mixed K/Na cation coordination environments are shown to result in a polar structure (space group Pna21). The crystal structure analysis of the Na/K-O/F interactions reveals that the potassium cations form one of the two contacts to the under-bonded oxide ions. These interactions satisfy the expected bond valence sums and Pauling's second crystal rule (PSCR), leading to O/F ordering and acentric packing of the [NbOF5]2− anionic unit.

scholarly journals New platforms for gas separations and storage, chemical sensing, and catalysis

2014 ◽  
Vol 70 (a1) ◽  
pp. C1221-C1221
Author(s):  
Michael Zaworotko ◽  
John Perry
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Crystal Engineering ◽  
Chemical Sensing ◽  
High Performance ◽  
Rational Design ◽  
Gas Storage ◽  
Structure Property ◽  
Energy Applications ◽  
Metal Organic

"Over the past two decades Metal-Organic Materials (MOMs), as exemplified by porous coordination polymers, discrete metal-organic polyhedra and metal-organic frameworks, have experienced tremendous growth in both the number of research papers and their impact. MOMs are receiving such attention thanks to their modular nature which affords them the potential to offer game-changing solutions for several important technological problems. MOMs can exhibit permanent porosity and many of their most anticipated applications, such as gas storage (carbon dioxide sequestration, natural gas, and hydrogen storage for energy applications), chemical separations, chemical sensing, catalysis, and drug delivery, involve the uptake or encapsulation of guests. Further, as they can often be obtained in a crystalline form, MOMs are also well suited to act as platforms materials for probing structure-property relationships. This presentation will survey several promising new MOM platforms that are being pursued by our research group and will address their performance with respect to carbon dioxide capture and sequestration, natural gas storage, and catalysis. Additionally, we will place these results in the context of the ""2-step"" crystal engineering principles that guided our research into the rational design of these high-performance materials (see Figure)."

scholarly journals Improving Hydride Conductivity in Layered Perovskites via Crystal Engineering

2020 ◽  
Author(s):  
Harry W. T. Morgan ◽  
Harry J. Stroud ◽  
Neil Allan
Keyword(s):  
Crystal Engineering ◽  
Density Functional ◽  
Rational Design ◽  
Ionic Mobility ◽  
Theory Approach ◽  
Ion Migration ◽  
Energy Applications ◽  
Migration Pathway ◽  
Migration Pathways ◽  
Layered Perovskites

Hydride ion conduction in layered perovskites is of great interest for sustainable-energy applications. In this report we study Ba2ScHO3, a recently synthesized oxyhydride with an unusual anion ordering, using a multifaceted density functional theory approach involving both transition state calculations and molecular dynamics simulations. Beyond simply identifying the key ion migration pathways, we perform detailed analysis of transition states and identify key interactions which drive trends in ionic mobility. Our key findings are that ionic mobility is, remarkably, independent of hydride-oxide disorder, the dominant migration pathway changes under pressure, and a reduction in A-site cation size accelerates hydride diffusion. Local structural flexibility along migration pathways is understood in terms of dimensionality and ionic size, and we thus identify crystal engineering principles for rational design of ion conductors. On the basis of our new insights into these materials, we predict that Sr2ScHO3 will show improved conductivity over existing analogues.

Sign in / Sign up

Export Citation Format

Share Document