NUS Chemistry Distinguished Lectureship

October 2023

24 Oct 2023

10.30 – 12.00

U-Hall Auditorium

Scientific Lecture

Speaker: Professor Omar M. Yaghi, James and Neeltje Tretter Chair Professor of Chemistry, University of California, Berkeley, USA

Lecture Title: Molecular Weaving

Abstract:The synthesis of covalently-linked organic extended structures has been a long-standing objective. The fundamental problem is that attempts to link organic molecular building blocks into extended structures often led to intractable amorphous solids and ill-defined materials, thus impeding development of this field. This changed when the reaction and crystallization conditions for making covalent organic frameworks (COFs) were worked out and reported in 2005 for 2D COFs and 2007 for 3D COFs. This advance extended the field of organic chemistry beyond discrete molecules (0D) and polymers (1D) to infinite layered (2D) and network (3D) extended structures.

The ability to combine the strong bond approach of reticular chemistry with the mechanical bond results in unprecedented class of molecularly woven structures. This presentation will outline the strategies for carrying out molecular weaving using covalent organic framework building blocks. The result is a vast chemical space in which robustness and porosity are combined with flexibility to yield materials of exceptional resiliency and mechanical properties. The reaction chemistry and crystallization methodologies for producing woven structures in which threads are interlaced, and rings and polyhedra are interlocked will be discussed. The inclusion chemistry and evolution of dynamics in these systems will also be presented. Details can be found here. 

23 Oct 2023

10.30 – 12.00

U-Hall Auditorium

Public Lecture

Speaker: Professor Omar M. Yaghi, James and Neeltje Tretter Chair Professor of Chemistry, University of California, Berkeley, USA

Lecture Title: Reticular Chemistry for Carbon Capture and Water Harvesting from Desert Air

Abstract: The extra carbon in the air is impacting our climate in ways detrimental to our lives and livelihoods. This climate challenge is also exacerbating the long-standing water stress in the world. Reticular Chemistry in the form of ultra-porous crystals called metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) can be designed to seek out and capture carbon dioxide from air to address the climate challenge. The thermal and chemical stability as well as the flexibility with which these harvesting structures can be made and modified has also led to trapping water from air to provide clean water anywhere in the world at any time of the year. Details can be found here

January 2023

17 Jan 2023

10.30 – 12.00

U-Hall Auditorium

Public Lecture

Speaker: Professor David MacMillan, the James S. McDonnell Distinguished University Professor of Chemistry at Princeton University, USA. 

Lecture Title: The Path to Invention and Discovery in Catalysis

Abstract: This lecture will describe the development of asymmetric organocatalysis in his laboratory. As part of this overview, he will explore concepts of chemical reactivity, catalysis, and the asymmetry of organic molecules. He will examine the impact of organocatalysis on modern synthetic chemistry and explore real-world applications of this technology. He will discuss the ways in which organocatalysis created a bridge to the development of a new field of research in his lab: visible light photoredox catalysis. Last, he will look to the future and consider how organocatalysis may continue to impact scientific research and society. Details can be found here

16 Jan 2023

10.30 – 12.00

U-Hall Auditorium

Scientific Lecture

Speaker: Professor David MacMillan, the James S. McDonnell Distinguished University Professor of Chemistry at Princeton University, USA. 

Lecture Title: The Development of Asymmetric Organocatalysis and Metallaphotoredox

Abstract: This lecture will first discuss the advent of organocatalysis in his laboratory. As part of this overview, he will highlight why organic catalysts have become widely explored in modern synthetic chemistry. This lecture will also discuss the application of visible light photocatalysis to the discovery or invention of transformations that will be conceptually or synthetically valuable. He will describe why a healthy balance of reaction discovery and mechanistic understanding has been important to the development of a field of research that is now being widely adopted in both industrial and academic settings.  In particular, he will discuss the application of photocatalysis to the development of new metallaphotoredox reactions involving copper, a development that we hope will have an impact on the discovery of new biologically relevant molecules. Finally, he will examine an exciting recent application of photoredox catalysis in his group; namely, the high-resolution µMap technology, which provides a powerful means to probe biological pathways at the subcellular level. Details can be found here