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Quantification of Solid Structure Similarity. Thomas Gelbrich University of Southampton. Compound. A. B. C. D. E. Polymorphic forms. Crystal Structure. i. ii. Construct. 3D. 2D. 1D. 0D. Formation of crystals Crystal engineering Prediction …. “Family”. ?.
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Quantification of Solid Structure Similarity Thomas Gelbrich University of Southampton
Compound A B C D E Polymorphic forms Crystal Structure i ii Construct 3D 2D 1D 0D
Formation of crystals • Crystal engineering • Prediction • … “Family” ? Robust building blocks
A B Construct
A B Method Construct
A B ? Construct
Construct, Cluster and Shell Shell of a molecule in a crystal structure One molecule + nearest neighbours • Representative cluster of a supramolecular construct • All independent molecules + their nearest neighbours: • Representative • Similar constructs have similar clusters • Component of a shell
Construct, Cluster and Shell Similar constructs >> Similar clusters >> Shells will contain certain similar components • Generate all shells • Identify similar components in shells • These are the representative clusters of a common construct
Corresponding Points A CPS 1. 2. 3. 4. 5. B C1 C2 O5 S1 N2 C11 C23 O3 S1 N1 Pairs of points which would conceivably adopt similar relative positions in different instances of a supramolecular construct.
Example 1 (i) (ii) II Hecht et al., Z. Anorg. Allg. Chem.,624 (1998), 315.
Example 1 – Shell (i) (ii)
Example 1 (i) (ii)
A B CIF, CP CIF, CP General information Corresponding vectors Degree of similarity Construct
N (N-1) / 2 individual tests NT 4 6 20 190 50 1225 200 19900 Construct Construct Construct Construct Construct Construct Families of N Structures N Structures
X~IX~CF3CH3~CF3(X = CF3, I, Br, Cl, F, H) Br~Br(ii) Br~Br (i)I~BrCF3~Cl Br~Br (iii)I~ClI~Br (ii)I~I (iii) CN~Br (i)CN~CN 3D 2D C2 C3 C1 1D I-Dimer 0D
Example 3 – Alkali and ammonium H-tartrates Chiral / racemic pairs : hydrogen tartrates racemic chiral
H2O QAPTEG ZELRUD LIGXEE BYPTAR10 [ ] H2O ½ ENHTAR H2O NETXAL HIDGOQ Example 3 –144 structures of H-tartrates racemic / chiral: K+, Rb+, Cs+, NH4+, Tl+, mixed crystals
Example 3 – Chains A 55 Structures B 34 Structures
Example 4 – Small degree of packing similar similarity
Example 4 – Small degree of packing similar similarity
Examples Racemic / chiral alkali and ammonium H-tartrates Gelbrich et al., Z. Anorg. Allg. Chem.,630 (2004), 1451. AgI/ FeII coordination polymers Krautscheid et al., Z. Anorg. Allg. Chem.,630 (2004), 1427. Polymorphism in TNT Vrcelj et al., Cryst Growth Des.,3 (2003), 1027.
Conclusion • Polymorphs • Multi-component structures • Coordination polymers • Small degree of packing similarity • Large families (N > 100)
What next? • Reverse search • (find matching structures to a known construct ) • GUI / Output . • . • . • Database of supramolecular constructs