Projects per year
Abstract
Seven multi-component molecular crystals containing O-H⋯O/O+-H⋯O- and N+-H⋯O- short strong hydrogen bonds (SSHBs) have been engineered by combining substituted organic acids with hydrogen bond acceptor molecules N,N-dimethylurea and isonicotinamide. In these materials, the shortest of the SSHBs are formed in the N,N-dimethylurea set for the ortho/para nitro-substituted organic acids whilst a twisted molecular approach favours the shorter SSHBs N+-H⋯O- in the isonicotinamide set. Temperature dependent proton migration behaviour has been explored in these systems using single crystal synchrotron X-ray diffraction (SCSXRD). By using a protocol which considers a combination of structural information when assessing the hydrogen atom (H-atom) behaviour, including refined H-atom positions alongside heavy atom geometry and Fourier difference maps, temperature dependent proton migration is indicated in two complexes (2: N,N-dimethylurea 2,4-dinitrobenzoic acid 1 : 1 and 5: isonicotinamide phthalic acid 2 : 1). We also implement Hirshfeld atom refinement for further confidence in this observation; this highlights the importance of having corroborating trends when applying the SCSXRD technique in these studies. Further insights into the SSHB donor-acceptor distance limit for temperature dependent proton migration are also revealed. For the O-H⋯O/O+-H⋯O- SSHBs, the systems here support the previously proposed maximum limit of 2.45 Å whilst for the charge assisted N+-H⋯O- SSHBs, a limit in the region of 2.55 Å may be suggested.
Original language | English |
---|---|
Pages (from-to) | 5249-5260 |
Number of pages | 12 |
Journal | CrystEngComm |
Volume | 21 |
Issue number | 35 |
Early online date | 12 Aug 2019 |
DOIs | |
Publication status | Published - 21 Sept 2019 |
Funding
We acknowledge the support from the University of Bath and the Diamond Light Source Ltd for a studentship to L. K. S. C. C. W. and P. R. R. are grateful to the EPSRC for continued support (EP/K004956/1). We thank Florian Kleemis from the University of Bremen for his assistance in implementing the HAR software. We thank Diamond Light Source for access to beamline I19 (NR18193-1) for data for samples 2, 4, 6, 8. We thank the Advanced Light Source, LBNL for beamtime to collect on samples 1, 3, 5 and 7 and S. J. Teat and K. J. Gagnon for assistance. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under contract no. DE-AC02-05CH11231.
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics
Fingerprint
Dive into the research topics of 'Exploring short strong hydrogen bonds engineered in organic acid molecular crystals for temperature dependent proton migration behaviour using single crystal synchrotron X-ray diffraction (SCSXRD)'. Together they form a unique fingerprint.Projects
- 1 Finished
-
Applying Long-Lived Metastable States in Switchable Functionality via Kinetic Control of Molecular Assembly
Raithby, P. (PI), Burrows, A. (CoI), Lewis, D. (CoI), Marken, F. (CoI), Parker, S. (CoI), Walsh, A. (CoI) & Wilson, C. (CoI)
Engineering and Physical Sciences Research Council
1/11/12 → 30/04/18
Project: Research council