Crystallographic Databases: Search and Retrieval of Information from the Cambridge Structural Database

1994 ◽  
pp. 71-110 ◽  
Author(s):  
Frank H. Allen ◽  
Olga Kennard ◽  
David G. Watson
Author(s):  
E. Grothe ◽  
H. Meekes ◽  
R. de Gelder

The automated identification of chiral centres in molecular residues is a non-trivial task. Current tools that allow the user to analyze crystallographic data entries do not identify chiral centres in some of the more complex ring structures, or lack the possibility to determine and compare the chirality of multiple structures. This article presents an approach to identify asymmetric C atoms, which is based on the atomic walk count algorithm presented by Rücker & Rücker [(1993),J. Chem. Inf. Comput. Sci.33, 683–695]. The algorithm, which we implemented in a computer program namedChiChi, is able to compare isomeric residues based on the chiral centres that were identified. This allows for discrimination between enantiomers, diastereomers and constitutional isomers that are present in crystallographic databases.ChiChiwas used to process 254 354 organic entries from the Cambridge Structural Database (CSD). A thorough analysis of stereoisomerism in the CSD is presented accompanied by a collection of chiral curiosities that illustrate the strength and versatility of this approach.


1990 ◽  
Vol 55 (8) ◽  
pp. 2059-2065 ◽  
Author(s):  
Jaroslav Vojtěchovský ◽  
Jindřich Hašek ◽  
Jiří Ječný ◽  
Karel Huml

Title compound is triclinic, Mr = 461.60; P1, a = 9.158(1), b = 16.062(3), c = 19.472(3) Å, α = 110.69(1)°, β = 89.70(1)°, γ = 103.17(1)°, V = 2 600(1) Å3, Z = 4, Do = 1.15(3), Dc = 1.179(1) Mg m-3, λ(CuKα) = 1.5418 Å, μ = 0.509 mm-1, F(000) = 976 K, R = 0.040 for 8 059 unique observed reflections. Both symmetrically independent molecules show a different geometry of the 1,4-dihydropyridine ring: either the boat conformation with apexes C(sp3), N and boat angles 14.7(3)° and 10.3(2)° respectively, or the planar conformation. The conformation has been compared with similar dihydropyridines obtained from Cambridge Structural Database.


2020 ◽  
Vol 11 (32) ◽  
pp. 8373-8387 ◽  
Author(s):  
Peyman Z. Moghadam ◽  
Aurelia Li ◽  
Xiao-Wei Liu ◽  
Rocio Bueno-Perez ◽  
Shu-Dong Wang ◽  
...  

Large-scale targeted exploration of metal–organic frameworks (MOFs) with characteristics such as specific surface chemistry or metal-cluster family has not been investigated so far.


2002 ◽  
Vol 58 (3) ◽  
pp. 398-406 ◽  
Author(s):  
A. Guy Orpen

Applications of the data in the Cambridge Structural Database (CSD) to knowledge acquisition and fundamental research in molecular inorganic chemistry are reviewed. Various classes of application are identified, including the derivation of typical molecular dimensions and their variability and transferability, the derivation and testing of theories of molecular structure and bonding, the identification of reaction paths and related conformational analyses based on the structure correlation hypothesis, and the identification of common and presumably energetically favourable intermolecular interactions. In many of these areas, the availability of plentiful structural data from the CSD is set against the emergence of high-quality computational data on the geometry and energy of inorganic complexes.


2004 ◽  
Vol 76 (5) ◽  
pp. 959-964 ◽  
Author(s):  
J. Karolak-Wojciechowska ◽  
A. Fruzinski

Based on our contemporary studies on the structures of biologically active molecules, we focus our attention on the aliphatic chain and its conformation. That flexible spacer definitely influenced the balanced position of all pharmacophoric points in molecules of biological ligands. The one atomic linker and two or three atomic spacers with one heteroatom X =O, S, CH2, NH have been taken into account. The conformational preferences clearly depend on the heteroatom X. In the discussion, we utilize our own X-ray data, computation chemistry methods, population analysis, and statistical data from the Cambridge Structural Database (CSD).


Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.


2020 ◽  
Author(s):  
Stephanie Boer ◽  
Li-Juan Yu ◽  
Tobias Genet ◽  
Kaycee Low ◽  
Duncan Cullen ◽  
...  

<div><div><div><p>Despite their apparent similarity, framework materials based on tetraphenylmethane and tetraphenylsilane building blocks often have quite different structures and topologies. Herein, we describe a new silicon tetraamidinium compound and use it to prepare crystalline hydrogen bonded frameworks with carboxylate anions in water. The silicon-containing frameworks are compared with those prepared from the analogous carbon tetraamidinium: when biphenyldicarboxylate or tetrakis(4-carboxyphenyl)methane anions were used similar channel-containing networks are observed for both the silicon and carbon tetraamidinium. When terephthalate or bicarbonate anions were used, different products form. Insights into possible reasons for the different products are provided by a survey of the Cambridge Structural Database and quantum chemical calculations, both of which indicate that, contrary to expectations, tetraphenylsilane derivatives have less geometrical flexibility than tetraphenylmethane derivatives, i.e. they are less able to distort away from ideal tetrahedral bond angles.</p></div></div></div>


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