Our research focuses on the synthesis, characterisation and application of inorganic and inorganic-organic hybrid solids, and in particular porous solids such as zeolites and metal-organic frameworks. We pride ourselves in identifying unique opportunities, often from disparate areas of science, to impact both academic and industrial research. The following are the main areas of interest in the laboratory.
1. Ionothermal Materials Chemistry and Chiral Induction
The ionothermal method for the preparation and processing of solids, developed by in our laboratory, is widely viewed as a ground-breaking and world-leading advance in the field. The primary concept, first published in Nature, is the use of ionic liquids as both solvent and structure directing agent in the formation of unusual materials with unique structure and function. Originally designed for the synthesis of porous solids, the technique has been extended to almost all types of inorganic, organic and hybrid materials. The research has exploited the distinctive features of ionic liquids to develop a synthetic methodology that is now widely used. These features lead to the possibility of entirely new concepts that are unique to the ionothermal method, such as the use of ambient pressure solvothermal conditions, the controlled delivery of structure directing agents, anion control (and the exquisite control over water as a mineraliser it allows) and effective chiral induction etc, which have enabled the synthesis of many new materials that cannot be accessed using other routes. The work at St Andrews has stimulated a whole new field that is followed by many research groups around the world – since 2006 there have been several hundred research papers that use the term ‘ionothermal’ and several hundred more that can be traced back to the original Nature paper.
Translational Medicinal Chemistry – Porous materials in medicine
It is quite a paradox that many gases of medical interest are extremely toxic in larger amounts (e.g. nitric oxide, hydrogen sulfide, carbon monoxide), and so safe storage and delivery in only beneficial amounts becomes a major challenge. Morris’s research developed zeolites and metal-organic frameworks that show exceptional properties for this process, delivering controllable amounts of gas at biologically suitable rates. The research is truly translational – beginning in the chemistry laboratory and developing the in vitro biological testing, through in vivo testing first in animal models and then to humans (and in fact well into the commercialisation phase). The research is also truly multidisciplinary – encompassing chemistry, biology, medicine and materials science.
We have many notable firsts in this area – the first demonstration of a biological action of metal-organic frameworks (anti-thrombosis activity in human blood) and the first clinical experiments on human skin (completed at Edinburgh Royal Infirmary) to name but two. This primarily commercially-targeted applications research is also underpinned by leading science in the synthesis and characterisation. The high level characterisation of the gas-framework interactions has been vital to the development of a real understanding of the ongoing processes in the applications.
New concepts in Metal-Organic Framework (MOF) Chemistry
During our research into MOFs we have also developed several new concepts in that have been published in high impact journals. One example is ‘hemilabile’ MOFs, where unique properties (such as ultraselective adsorption) can be engineered into a material by controlling the relative bonding in different parts of the structure. In addition he has also developed the very first example of a MOF where adsorption can be switched between two channels with different surface chemistries on demand. As always the new concepts are underpinned by exquisite chemical and structural studies, deciphering features such as the synthesis mechanisms of the in situ ligand functionalisation that is vital for switchable adsorption.
New Concepts in Zeolite Synthesis – the ADOR process
In addition to ionothermal synthesis described above, we have been particularly involved in developing other new concepts in zeolite preparative science. Prime amongst these is the very recent development of the ADOR principle (Assembly-Disassembly-Organisation-Reassembly), a technique whereby a preformed zeolite can be disassembled through selective chemistry into its constituent units, before being reassembled into a new zeolite with, importantly, a predictable structure. This latter feature, a designer zeolite, has been one of the holy grails of the field. He has shown how he can prepare a family of zeolites with targeted pore sizes and channel systems starting from a 14 x 12 ring system, and then systematically replace structural units to make a two materials with a 12 x 10 ring and a 10 x 8 ring system respectively. This is the first time such a top down approach has been used to make new zeolites, and of great significance to the field, the first time that zeolites with targeted pore sizes have been prepared.
Characterisation: Powder and Microcrystal X-ray diffraction, NMR and PDF
A continuing theme throughout our work has been the development and application of cutting edge characterisation, especially in the area of X-ray diffraction. Early work concentrated on powder diffraction, but since the mid-nineties we have been a major developer of X-ray diffraction on micron-sized crystals at synchrotron sources around the world. His work allowed not only the structure solution of novel and exciting materials but also enabled mechanistic studies of interesting physical properties of zeolites, such as negative thermal expansion. The simultaneous use of multiple techniques to solve complex problems that are not tractable using one technique alone is a recurring aspect of Morris’s research. Diffraction studies combined with solid-state NMR and X-ray PDF allowed the solution of structural problems and the solution of zeolite and MOF architectures.
A feature of Morris’s research has been his ability to make connections between seemingly disparate areas of science and invent new areas of research. Another good example of this is his identification of silsesquioxane molecules as similar to zeolite secondary building units and that they could be chemically modified to produce molecules that combined properties of zeolites and dendrimers. As well as developing the initial synthesis chemistry, which had the important advantage over some dendrimer chemistries of producing large numbers of end groups at low generation numbers, Morris then applied the dendrimers in various areas, including a demonstration of the first so-called positive dendrimer effect on a homogenously-catalysed reaction.
Industrial and Commercial Chemistry
A significant recent focus of our research has been the translation of his leading academic research into industrial and commercial impact. His medical gas delivery technology has led to a large commercial licence at St Andrews and a subsequent spin out company (Zeomedix) who are taking the technology to the market place through clinical trials. He also leads a major Scottish initiative to develop new multifunctional anti-bacterial matreials, with another spin-out company (MOFgen) currently in the process of being formed. This commercially-focussed activity has led to several awards from the Royal Society (e.g. Brian Mercer Award for Innovation), the Royal Society of Edinburgh, GEMI (Germany) and the Royal Society of Chemistry Applied Inorganic Chemistry award.