Introduction

Please follow the links below or on the left for more details:

• What is Z' - An introduction to Z'
• Z' Limitations - A guide to some common pitfalls and problems with the definition of Z'
• Our Work - An overview of our research on structures with high Z'
• Database - A database of known structures with Z' > 4
• Literature - A selection of papers concerning the Z' phenomenon
• Submit - Please add to our database by submitting your unpublished high Z' structures
• Useful Links - Some useful websites
• Steed Research Group - A link to the Durham Supramolecular Chemistry group homepage

• 21/9/18 - Schönleber and coworkers have redetermined the ostensibly Z' = 32 structure of trimethyl tin hydroxide and shown it to be a Z' = 4 a × b × 8c eight-fold superstructure with orthorhombic P2₁cn symmetry.
• 21/9/18 - The Z' database has been updated with the May and Aug CSD updates. This includes a remarkable Z' = 24 structure arising from an incomplete spin crossover transition published by Halcrow and coworkers, refcode VIFXEQ.
• 29/3/18 - The Z' database has been updated to cover structures up to and including the Nov 2017 and Feb 2018 updates of v5.39 of the Cambridge Structural Database.
• 14/11/17 - The Z' database has been updated to cover structures up to and including the May 2017 update of v5.38 of the Cambridge Structural Database and earlier missing entries have been restored.
• 12/16 - Prof. Carol Brock has published an extremely useful critical analysis of high Z' structures entitled High-Z' structures of organic molecules - have a look at it and other reviews in our Literature section 
• 6/8/15 - The Z' world record has been broken! A recent report by Zentner and coworkers in Chem. Commum. entitled "High surface area and Z ' in a thermally stable 8-fold polycatenated hydrogen-bonded framework" reports a hydrogen bonded framework with Z' = 56, shattering the previous world record of 32 for Me₃SnOH which had stood since 1965.
• 12/2/15 - Our comprehensive review "Packing Problems: High Z' Crystal Structures and their Relationship to Cocrystals and Polymorphism", has just been published in Chem. Rev. 2015 .
• 02/09/14 - Site URL changed to zprime.co.uk. Updates added so that the site is complete for Z' > 4 up to the May 2014 CSD release (see Database). Literature section significantly expanded and further subdivided.
• 22/09/09 - Our paper "Designing Co-Crystals of Pharmaceutically Relevant Compounds That Crystallize with Z' > 1" is featured in the Virtual Issue on Pharmaceutical Co-crystals published in Crystal Growth & Design

We would like to thank Professor Len Barbour (University of Stellenbosch, South Africa) for his invaluable assistance.
We would also like to thank the EPSRC for funding (Grant Numbers: EP/D040329/1 and EP/E031153).

This site is dedicated to Dr. Andrés E. Goeta.

If you have any questions or queries about this site then please let us know.
If you have a high Z' structure which you would like to add to the database then please click here.
For more information on research in our group, please visit our research group homepage.