About
Dewald P. van Heerden completed his PhD in 2020 under the supervision of Leonard Barbour at the University of Stellenbosch with the project titled Computational Assessment and Visualization of Guest Inclusion in Porous Crystalline Materials. Soon thereafter, he joined the Structural Biology Research Unit at the University of Cape Town as a postdoctoral research fellow under the mentorship of Trevor Sewell. His current research interests are focused on the computational elucidation of the reaction mechanisms of the nitrilase superfamily.
Selected recent publications
1485676
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1.
van Heerden, D. P. & Barbour, L. J. Guest-occupiable space in the crystalline solid state: a simple rule-of-thumb for predicting occupancy. Chemical Society Reviews 50, 735–749 (2021). Cite
1.
Van Heerden, D. P., Smith, V. J., Aggarwal, H. & Barbour, L. J. High Pressure In Situ Single‐Crystal X‐Ray Diffraction Reveals Turnstile Linker Rotation Upon Room‐Temperature Stepped Uptake of Alkanes. Angewandte Chemie 133, 13542–13547 (2021). Cite
1.
Korica, M. et al. Inclusion of CO2, NH3, SO2, Cl2 and H2S in porous N4O4-donor macrocyclic Schiff base. Microporous and mesoporous materials 332, 111708 (2022). Cite
1.
Heerden, V. & Pepler, D. Computational assessment and visualization of guest inclusion in porous crystalline materials. (Stellenbosch : Stellenbosch University, 2020). Cite