Shape-selective crystallisation of fluxional carbon cages

Aisha N. Bismillah, Jiri Sturala, Brette M. Chapin, Dmitry S. Yufit, Paul Hodgkinson, Paul R. McGonigal*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Dynamic covalent rearrangements of fluxional carbon cages, such as bullvalenes and barbaralanes, impart 'shapeshifting' molecular properties. Here, a series of five barbaralanes each interconvert dynamically between two constitutional isomers in solution, but resolve to single isomers upon crystallisation. Unexpectedly, the minor solution-phase isomers are resolved in two instances. Through dynamic NMR, crystallographic and DFT analyses, we show that the isomer observed in the solid state is not a direct consequence of the equilibrium distribution in solution or any specific noncovalent interactions. Rather, the dynamic preferential crystallisation is dictated by differences in molecular size and shape.

Original languageEnglish
Pages (from-to)8631-8636
Number of pages6
JournalChemical Science
Issue number46
Publication statusPublished - 2018

Bibliographical note

Funding Information:
A. N. B. acknowledges an EPSRC DTG. J. S. acknowledges an Experientia Foundation Fellowship, Advanced Functional Nanorobots (CZ.02.1.01/0.0/0.0/15_003/0000444 nanced by the EFRR), and computational resources from the MSMT under the CESNET (LM2015042) and CERIT-Scientic Cloud (LM2015085) projects. B. M. C. and P. R. M. thank the EPSRC for funding (EP/ N029992/1). We thank Dr Mark Miller and Prof. Jon Steed for useful discussions. We are grateful to Dr David Apperley and Dr Raquel Belda-Vidal for assistance with NMR measurements.

Publisher Copyright:
© The Royal Society of Chemistry 2018.

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