Chi-Ming Che is currently the Dr Hui Wai-Haan Chair of Chemistry at the University of Hong Kong.

Professor Che's research interests encompass a diverse area, including inorganic and organic synthesis, metal-catalyzed organic transformations, mechanism of nitrogen fixation, organometallic and inorganic photochemistry, electron transfer reactions in biological systems, synthesis of chiral metal complexes and asymmetric oxidation of alkenes. 

He has been publishing his research in ChemComm since 1979 and is listed among our most cited authors. 

 

What was your first article published in ChemComm? 

As a Ph.D. student, my first publication with my Ph.D. supervisor, Professor C.-K. Poon, was published in ChemComm (J. Chem. Soc., Chem. Commun., 1979, 861). However, my first publication as a corresponding author was when I returned from the California Institute of Technology (Caltech) to take up a position as a faculty member of the Chemistry Department at the University of Hong Kong (HKU) in the middle of 1983, was also in ChemComm. This paper was titled "Synthesis and Characterisation of a Ruthenyl (RuIV=O) Complex with a Saturated Macrocyclic Tetramine" (J. Chem. Soc., Chem. Commun., 1984, 641). This was my first work to kick-start the chemistry of high-valent macrocyclic ruthenium-oxo complexes in Hong Kong. 

Que and co-workers also employed the 14-tmc as a ligand to stabilise high-valent Fe(IV)=O, and the crystal structure of [FeIV(14-tmc)O(CH3CN)]2+ was published in Science, 2003, 299, 1037. The Fe(IV)=O complex reported by Que is isostructural to the Ru(IV)=O complex published in our earlier work in Chem. Commun., 1985, 546. 

Why do you choose to publish your work in ChemComm?

I received my B.Sc. and Ph.D. education at HKU, which was and probably still is a British-style institution. ChemComm has been regarded to be a top journal with a very high international reputation in the field of Chemical Sciences. Indeed, many of my innovative works were published in ChemComm and I consider that ChemComm carries the tradition of excellence to the 21st century. It is always a pleasure to read the many stimulating and original chemistry articles published in ChemComm. This is truly an international chemistry journal with submissions from every part of world and with a fair and rigorous referee system and that is why I submit my work there. 

Tell me about your three most significant papers published in ChemComm. 

I have chosen three articles from the early stage of my career that I consider having impact. The first one, published in 1985, is on the "Characterisation of a High-Valent Ruthenyl (RuIV=O) Cation Stabilized by the Macrocyclic 1,4,8,11-Tetramethyl-1,4,8,11-tetraazacyclotetradecane (tmc) Ligand: Crystal and Molecular Structure of trans-[RuIV(tmc)O(CH3CN)][PF6]2" (J. Chem. Soc., Chem. Commun., 1985, 546). This paper described the first crystal structure of mono oxo-ruthenium complexes, which have been demonstrated to have rich oxidation chemistry. Indeed, ruthenium-oxo complexes remain a unique class of reactive metal-oxo oxidants, in that they are reactive toward organic oxidation but can be isolated with diverse auxiliary ligands. In addition, complexes of ruthenium ions in different oxidation states, tuneable redox potentials and with the oxo ligands in both cis and trans configurations can also be prepared and structurally characterised. The use of tmc as a ligand to stabilise highly reactive metal-oxo complexes has subsequently been adopted by Que and co-workers for preparation and structural determination of non-heme oxo-iron(IV) complexes. 

The second paper is entitled "Model Reactions for Nitrogen Fixation. Photo-Induced Formation and X-Ray Crystal Structure of [Os2(NH3)8(CH3CN)2(N2)]5+ from [OsVI(NH3)4N]3+" (J. Chem. Soc., Chem. Commun., 1989, 1883). This paper provided the first evidence including kinetics and structural determination of reaction products for bimolecular nitrido coupling reactions to give µ-dinitrogen complexes, which were proposed by Taube and co-workers in 1979. Using the principle of microscopic reversibility, observation of nitrido coupling reactions would imply that the cleavage of dinitrogen complexes to nitrido complexes could take place under certain conditions. Indeed, six years after publication of this work in 1995, Cummins and co-workers at Massachusetts Institute of Technology reported the cleavage of dinitrogen to nitrido metal complexes using molybdenum (III) catalysts, and the work was published in Science, 1995, 268, 861. 

The third paper entitled "Spectroscopic Properties and Redox Chemistry of the Phosphorescent Excited Stateof [Au2(dppm)2](ClO4)2 (dppm = bis(diphenylphosphino) methane)" was published in 1989 (J. Chem. Soc., Chem. Commun., 1989, 885). This paper, together with a similar work published by Fackler and co-workers in Inorganic Chemistry in the same year (Inorg.Chem.,1989, 28,2145), marked the development of luminescent gold(I) chemistry, which has now become a topic of immense interest. I should emphasise that the phosphorescence of [Au2(dppm)2]2+ remains unique since, besides its high quantum yield and long life-time, the [Au2(dppm)2]2+* emission features an interesting example of highly emissive molecular exciplex from a metal-centred excited state. Excited state complex formation leading to exciplex emission could form the operatingprinciple of luminescent signalling for molecular recognition. The gold(I) photoluminescence, in essence, has stimulated the interest of various groups to develop the photochemistry and photophysics of two- and three-coordinate metal complexes. I expect that the interest will continue in the forthcoming decades. 

How has your research changed since you first began publishing in ChemComm? 

Well, I am still interested in the chemistry of reactive metal-ligand multiple bonded complexes and phosphorescent metal complexes of platinum group metals. My research, in essence, has not significantly changed but the methodologies used for illustrating the importance of inorganic chemistry to the society have changed. I consider inorganic chemistry has a lot of potential to excel in materials science, catalysis, and medicines. For these reasons, we have recently engaged in developing practical applications of metalloporphyrins in organic synthesis, chemical biology of structurally defined inorganic compounds, and phosphorescent metal compounds for optoelectronics. But the innovative part would remain the design and understanding the bonding properties, particularly the properties arising from weak interactions of metal-organic compounds, either in their molecular forms or in supramolecular assemblies. 

What is the inspiration behind your research?

Well, I am interested in the life style of a scientist in that I can do the kind of things that I like. In this regard, the Universityof Hong Kong has been very supportive to my research. An inspiration would be to train and develop my students to acquire self-confidence and to have clear and critical thinking through doing research with me. I consider that innovative research is of great importance to the development of Chinain the forthcoming decades. 

What part of your research are you most proud? 

I am satisfied with my research on ruthenium-ligand multiple bonded complexes and phosphorescent coordinatively unsaturated metal complexes. The formerrelates to my interest in catalysis, whereas the latter is on the excited state chemistry. I am happy with my work in understanding reactive molecules, either in their ground states or in the triplet excited states. I consider that shining light to molecules is a means to synthesise new molecules that are highly energetic, though short-lived. Thus, I should say I am interested in synthetic chemistry. 

Where do you see yourself in 10-15 years time?

I believe that I will still be doing research in 10-15 years time, but perhaps more into interdisciplinary areas such as medicinal inorganic chemistry. I hope to really focus on just one area of research once I am in my fifties. I have not yet decided which area I should focuson, either in catalysis or excited state chemistry, or simply hard-core inorganic chemistry. I am very interested in hard-core synthetic chemistry, but I do not know whether I could get the funding to do pure basic chemistry research nowadays. 

What scientists do you most admire? 

Of course I admire my mentors, Professor C.-K. Poon and Professor Harry B. Gray since they taught me a lot. I admire Linus Pauling. When I was a high school student, I read a book by Linus Pauling on the Nature of Chemical Bond, and I still consider that chemical bonding is the essence of my research and I am still trying hard to understand it. Professor Harry B. Gray's research on photochemistry of metal compounds has really inspired my interest in this area. After my return from Caltech to HKU, I employed synthetic chemistry approach for the photochemistry research.