Organic Crystal Engineering with Piperazine-2,5-diones. 4. Crystal Packing of Piperazinediones Derived from 2-Amino-7-cyano-4-methoxyindan-2-carboxylic Acid

2003 ◽  
Vol 3 (5) ◽  
pp. 811-821 ◽  
Author(s):  
Bhumasamudram Jagadish ◽  
Michael D. Carducci ◽  
Christian Bosshard ◽  
Peter Günter ◽  
Jason I. Margolis ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Organic Crystal

Organic crystal engineering with piperazine-2,5-diones. 2. Crystal packing of weakly dipolar piperazinediones derived from 2-amino-4-bromo-7-methoxyindan-2-carboxylic acid

Tetrahedron ◽  
1999 ◽  
Vol 55 (50) ◽  
pp. 14301-14322 ◽  
Author(s):  
Lawrence J. Williams ◽  
B. Jagadish ◽  
Michael G. Lansdown ◽  
Michael D. Carducci ◽  
Eugene A. Mash
Keyword(s):  
Carboxylic Acid ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Organic Crystal

Organic Crystal Engineering with 1,4-Piperazine-2,5-diones. 7. Crystal Packing of Piperazinediones Derived from 2-Amino-7-nitro-4-methoxyindan-2-carboxylic Acid

2008 ◽  
Vol 8 (9) ◽  
pp. 3257-3270 ◽  
Author(s):  
Deogratias Ntirampebura ◽  
Bhumasamudram Jagadish ◽  
Gary S. Nichol ◽  
Michael D. Carducci ◽  
Alice Dawson ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Organic Crystal

Organic Crystal Engineering with 1,4-Piperazine-2,5-diones. 8. Synthesis, Crystal Packing, and Thermochemistry of Piperazinediones Derived from 2-Amino-4,7-dialkoxyindan-2-carboxylic Acids

2012 ◽  
Vol 12 (10) ◽  
pp. 5056-5068 ◽  
Author(s):  
Kirk E. Wells ◽  
Robin A. Weatherhead ◽  
Francis N. Murigi ◽  
Gary S. Nichol ◽  
Michael D. Carducci ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Organic Crystal

Organic crystal engineering with piperazine-2,5-diones. 1. Crystal packing of piperazinediones derived from substituted 2-aminoindan-2-carboxylic acids

Tetrahedron ◽  
1999 ◽  
Vol 55 (50) ◽  
pp. 14281-14300 ◽  
Author(s):  
Lawrence J. Williams ◽  
B. Jagadish ◽  
Scott R. Lyon ◽  
Robin A. Kloster ◽  
Michael D. Carducci ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Organic Crystal

scholarly journals Towards computer-guided tuning of the crystal packing of porous organic cages

2014 ◽  
Vol 70 (a1) ◽  
pp. C667-C667
Author(s):  
Angeles Pulido ◽  
Ming Liu ◽  
Paul Reiss ◽  
Anna Slater ◽  
Sam Chong ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Engineering ◽  
Molecular Sieves ◽  
Structure Prediction ◽  
Crystal Packing ◽  
Aromatic Aldehydes ◽  
Lattice Energy ◽  
Building Blocks ◽  
Molecular Assembly ◽  
Computational Techniques

Among microporous materials, there has been an increasing recent interest in porous organic cage (POC) crystals, which can display permanent intrinsic (molecular) and extrinsic (crystal network) porosity. These materials can be used as molecular sieves for gas separation and potential applications as enzyme mimics have been suggested since they exhibit structural response toward guest molecules[1]. Small structural modifications of the initial building blocks of the porous organic molecules can lead to quite different molecular assembly[1]. Moreover, the crystal packing of POCs is based on weak molecular interactions and is less predictable that other porous materials such as MOFs or zeolites.[2] In this contribution, we show that computational techniques -molecular conformational searches and crystal structure prediction- can be successfully used to understand POC crystal packing preferences. Computational results will be presented for a series of closely related tetrahedral imine- and amine-linked porous molecules, formed by [4+6] condensation of aromatic aldehydes and cyclohexyl linked diamines. While the basic cage is known to have one strongly preferred crystal structure, the presence of small alkyl groups on the POC modifies its crystal packing preferences, leading to extensive polymorphism. Calculations were able to successfully identify these trends as well as to predict the structures obtained experimentally, demonstrating the potential for computational pre-screening in the design of POCs within targeted crystal structures. Moreover, the need of accurate molecular (ab initio calculations) and crystal (based on atom-atom potential lattice energy minimization) modelling for computer-guided crystal engineering will be discussed.

scholarly journals Crystal structures of 2-aminopyridine citric acid salts: C5H7N2 +·C6H7O7 − and 3C5H7N2 +·C6H5O7 3−

2018 ◽  
Vol 74 (8) ◽  
pp. 1111-1116 ◽  
Author(s):  
Shet M. Prakash ◽  
S. Naveen ◽  
N. K. Lokanath ◽  
P. A. Suchetan ◽  
Ismail Warad
Keyword(s):  
Hydrogen Bond ◽  
Citric Acid ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Crystal Engineering ◽  
Molecular Conformation ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Almost All

2-Aminopyridine and citric acid mixed in 1:1 and 3:1 ratios in ethanol yielded crystals of two 2-aminopyridinium citrate salts, viz. C5H7N2 +·C6H7O7 − (I) (systematic name: 2-aminopyridin-1-ium 3-carboxy-2-carboxymethyl-2-hydroxypropanoate), and 3C5H7N2 +·C6H5O7 3− (II) [systematic name: tris(2-aminopyridin-1-ium) 2-hydroxypropane-1,2,3-tricarboxylate]. The supramolecular synthons present are analysed and their effect upon the crystal packing is presented in the context of crystal engineering. Salt I is formed by the protonation of the pyridine N atom and deprotonation of the central carboxylic group of citric acid, while in II all three carboxylic groups of the acid are deprotonated and the charges are compensated for by three 2-aminopyridinium cations. In both structures, a complex supramolecular three-dimensional architecture is formed. In I, the supramolecular aggregation results from Namino—H...Oacid, Oacid...H—Oacid, Oalcohol—H...Oacid, Namino—H...Oalcohol, Npy—H...Oalcohol and Car—H...Oacid interactions. The molecular conformation of the citrate ion (CA3−) in II is stabilized by an intramolecular Oalcohol—H...Oacid hydrogen bond that encloses an S(6) ring motif. The complex three-dimensional structure of II features Namino—H...Oacid, Npy—H...Oacid and several Car—H...Oacid hydrogen bonds. In the crystal of I, the common charge-assisted 2-aminopyridinium–carboxylate heterosynthon exhibited in many 2-aminopyridinium carboxylates is not observed, instead chains of N—H...O hydrogen bonds and hetero O—H...O dimers are formed. In the crystal of II, the 2-aminopyridinium–carboxylate heterosynthon is sustained, while hetero O—H...O dimers are not observed. The crystal structures of both salts display a variety of hydrogen bonds as almost all of the hydrogen-bond donors and acceptors present are involved in hydrogen bonding.

scholarly journals Tuning colour in multi-component complexes: Molecular disorder as a design tool

2014 ◽  
Vol 70 (a1) ◽  
pp. C1007-C1007
Author(s):  
Charlotte Jones ◽  
Chick Wilson ◽  
Lynne Thomas
Keyword(s):  
Single Crystal ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Colour Change ◽  
Molecular Complexes ◽  
Design Tool ◽  
Layered Crystal ◽  
Molecular Rearrangement ◽  
Organic Systems ◽  
Inorganic Systems

The key aim of multi-component crystallisation is modification of the physicochemical properties for a specific task.[1] Tuning colour using molecular components is a relatively unexplored area, which is surprising given the possible advantages in pigment development. In crystalline materials, the optical characteristics are not solely dependent on the molecules but also on the crystal packing;[2] it follows that the optical properties could be modified using crystal engineering techniques. We have systematically investigated co-crystallising haloanilines with dinitrobenzoic acids to build an understanding of the intermolecular interactions. Molecular disorder of one or more of the components tends to lead to layered crystal structures that include stacking interactions and therefore strong colour, indicating that molecular disorder is desirable. Defects in inorganic systems are routinely exploited as a route to enhancing or introducing physical properties but similar effects in organic systems are yet to be properly exploited. We will discuss the methods by which disorder can be designed into molecular complexes, and the local ordering effects which give rise to strong diffuse scattering. Additionally we have identified a pair of thermochromic molecular complexes, 2-iodoaniline/2-bromoaniline 3,4-dinitrobenzoic acid, where disorder appears to be crucial in lending the materials their properties. Both complexes undergo a temperature-induced colour change from red to yellow corresponding to a significant molecular rearrangement. The thermochromic transition is a single-crystal to single-crystal effect; the role of molecular disorder as a facilitator for the molecular rearrangement, maintaining the crystal integrity, will be discussed. Despite the complexes being isostructural, only the bromoaniline complex shows reversible thermochromic behaviour; subtleties in the manifestation of this disorder can explain the differences in the reversibility of the transition.

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