High-resolution crystallographic studies on mechanically flexible crystals

Project description

Mechanically flexible molecular crystals have gained a significant research interest recently, owing to their implications in flexible electronics, actuators, pharmaceutical drug formulation, optical waveguides and in molecular ferroelectrics and piezoelectric materials [1-4]. Despite the increasing number of flexible molecular crystals that are being reported lately, there is a significant knowledge gap between in our understanding of the mechanism and structural factors leading to flexibility in crystals. Different models based on anisotropy, slip planes, mechanical interlocking, etc., are proposed to explain the flexible behavior in crystals [4-7]. However, there exists no consensus or structural model that explains the wide varieties of bending crystals that are reported. In this project, we aim to develop mechanistic models of flexibility in organic and metal-organic molecular crystals based on an in-depth structural analysis that combines quantum chemical calculations with high-resolution crystallography. We will employ advanced crystallographic techniques such as quantum crystallography, synchrotron micro-XRD mapping,[4] microscopic techniques, and nanoindentation measurements of the mechanical properties of a series of organic and metal-organic crystals. Our recent work in this direction indicates that building an understanding of the flexibility in such materials requires a multi-pronged approach [8]. The insights derived from these studies are expected to have implications in molecular materials such as flexible electronics, molecular piezoelectric sensors, and actuators.
The specific aims of the project will be:
1. To discover novel classes of molecular organic and metal-organic materials exhibiting mechanical flexibility and photophysical properties.
2. To employ high-resolution crystallographic studies to derive structure-property relations in these materials.

References
[1] Sun, C. C. In Pharmaceutical Crystals: Science and Engineering, Li, T., Mattei, A., Eds.; John Wiley & Sons: 2019.
[2] Thompson, A. J.; Orué, A. I. C.; Nair, A. J.; Price, J. R.; McMurtrie, J.; Clegg, J. K., Chem. Soc. Rev., 2021,50, 11725.
[3 ] P. Naumov, S. Chizhik, M. K. Panda, N. K. Nath, E. Boldyreva, Chemical Reviews, 2015, 115, 22, 12440-12490.
[4] Worthy, A.; Grosjean, A.; Pfrunder, M. C.; Xu, Y.; Yan, C.; Edwards, G.; Clegg, J. K.; McMurtrie, J. C., Nature Chemistry 2018, 10 (1), 65-69.
[5] Brock, A. J.; Whittaker, J. J.; Powell, J. A.; Pfrunder, M. C.; Grosjean, A.; Parsons, S.; McMurtrie, J. C.; Clegg, J. K., Angew. Chem. Int. Ed. 2018, 57 (35), 11325-11328.
[6] Thomas, S. P.; Shi, M. W.; Koutsantonis, G. A.; Jayatilaka, D.; Edwards, A. J.; Spackman, M. Angew. Chem., Int. Ed. 2017, 56, 8468–8472.
[7] Turner, M. J.; Thomas, S. P.; Shi, M. W.; Jayatilaka, D.; Spackman, M. A., Chem. Commun. 2015, 51, 3735.
[8] Thomas, S.P.; Worthy, A.; Eikeland, E. Z.; Thompson, A. J.; Grosjean, A.; Tolborg, K.; Krause, L., Sugimoto, K.; Spackman, M. A.; McMurtrie, J. C.; Clegg, J. K.; Iversen, B. B., Chem. Mater. 2023, 35, 6, 2495.

Outcomes

1. Discovery of novel classes of molecular organic and metal-organic materials exhibiting mechanical flexibility and photophysical properties.

2. Building structural and mechanistic models to explain the properties of these materials by combining quantum chemical methods and high-resolution crystallography.

3. Derive design inputs for the generation of such flexible materials having desirable opto-electronic properties.

Essential capabilities

Primary knowledge of chemistry , crystal growth and crystallography

Desireable capabilities

Essential chemistry lab experience, data analysis

Expected qualifications (Course/Degrees etc.)

Masters degree in Chemistry with courses on physical chemistry and material chemistry