Chemistry Tour De Force In Hungary

For centuries, chemists in Europe have been at the forefront of the molecular sciences, making discoveries that have changed the way we live and helping to tackle some of the most urgent problems facing the world today-for example, those relating to the environment, energy, health care, and medicine. Yet, despite the long history of chemistry in Europe, a congress on chemistry bringing together chemists from around Europe has never been held. That changed during the last week of August when the first-ever European Chemistry Congress took place at Eötvös Lorënd University, which is located on the west bank of the river Danube on the Buda side of Budapest, Hungary.

The meeting attracted 2,348 industrial, academic, and governmental chemists and molecular scientists from 57 countries. For the plenary sessions, the participants, just over 90% of whom were from Europe, gathered together in a white marquee, known as the plenary tent, on the university campus. The wind that blew along the Danube at times shook and rattled the tent but, apart from a few unsettling moments, failed to distract the audience or the plenary speakers from the chemistry that was presented.

The congress was organized by the European Association for Chemical & Molecular Sciences (EuCheMS) and cosponsored by the French Chemical Society, the German Chemical Society, and the U.K.'s Royal Society of Chemistry (RSC). EuCheMS was registered as a not-for-profit organization in Belgium earlier this year. Before 2004, it was known as the Federation of European Chemical Societies, which was founded in 1970. The association now has 50 member societies from 36 countries. The individual membership of the societies totals about 150,000.

The geographical diversity of Europe's chemical societies has led to a proliferation of national meetings and voices in European chemistry over the past century. EuCheMS aims to provide a powerful single voice for European chemists that addresses some of the major challenges faced today, both inside and outside the European Union.

"EuCheMS plans to establish European chemistry as a recognizable entity, comparable with the American Chemical Society in the U.S.," said W. James Feast, who became RSC president in July. Feast is a research professor at Durham University in England, and also works at Eindhoven University of Technology, in the Netherlands. "We have to put together the structures and mechanisms to support European chemistry for the sake of all our futures," he said. The Budapest congress was one of the initial steps in this mission.

"The growing need to enter into partnership with other science groups related to chemistry and the molecular sciences led European chemists to organize the congress," said congress Chairman Gábor Náray-Szabó, who is a past president of EuCheMS and the Hungarian Chemical Society and a chemistry professor at Eötvös Loránd University. "Our aim was to provide a showcase for chemical sciences in Europe," he told C&EN.

The meeting consisted of around 1,400 oral and poster presentations, including plenary lectures by five Nobel Laureates. A glance at the titles of the special topic symposia indicates the ambitious and wide-ranging nature of the congress. Symposia topics included theoretical and computational chemistry, spectroscopy, catalysis, medicinal chemistry, chemical imaging, nanomaterials, environmental chemistry, food and health, teaching, green and sustainable chemistry, polymer architecture, organic synthesis, coordination chemistry, biomolecules, and nuclear and radiochemistry. Some of the presentations are highlighted in meeting briefs that follow (see page 44).

Ahmed H. Zewail, professor of chemistry and physics at California Institute of Technology, was invited to present the opening plenary lecture. "Unlike the other plenary lecturers, I was not born in Europe, nor do I live in Europe, so I'm an honorary European today," he remarked. Zewail won the Nobel Prize in Chemistry in 1999 for his work on the development of femtochemistry, the study of fundamental chemical reactions on the femtosecond timescale using ultrashort laser flashes.

Zewail introduced some of the challenges facing chemists today by showing a letter, written in 2004 by a 10-year-old named Hani. "Although we can't see our future with a crystal ball, what we do today will affect our planet tomorrow," Hani wrote.

"Protecting our world now is an overriding challenge," Zewail said. "We can help to do this by making chemistry exciting for boys and girls. To do this, we need to get to the fundamentals of chemistry. And one of the fundamentals, which no other scientific discipline addresses, is the chemical bond."

The chemical bond is central to life, but it has been mainly studied in systems that are in equilibrium, he observed, adding that, in biological systems, structures are dynamic and often far from equilibrium.

"Nature employs huge and highly complex architectures to carry out specific and selective processes, for example, to move ions through channels in cells," he said. "One of the key challenges for chemists is understanding selectivity in biological systems. At present, we do not understand why there is a bias toward the formation of one complex structure rather than another for a specific function. And we know little about how dynamics influences and controls structure and function in biological systems."

The development of instruments that can image atoms in real time and enable us to visualize structures as they pass through transition states will help us to understand the bonding in and dynamics of complex structures that are not at equilibrium, according to Zewail. He calls this four-dimensional visualization, the four dimensions being time and the three dimensions of space.

Zewail described a technique known as 4-D ultrafast electron microscopy (UEM) that is being developed by his group. UEM relies on the use of femtosecond laser pulses to free electron packets, some containing only one electron, from a photocathode. "Electrons scatter more efficiently than X-rays and therefore allow us to obtain diffraction patterns with atomic resolution," he explained. "We can use the 4-D imaging technique to visualize complex systems and observe how chemical bonds are forming, changing, and breaking with femtosecond time resolution and angstrom spatial resolution. Eventually, we hope to use UEM for biological imaging, for example, to study how cell membranes and ion channels function."

Kurt Wüthrich, professor of biophysics at Swiss Federal Institute of Technology (ETH), Zurich, also described the use of instrumental techniques to explore the interface between chemistry and biology. Wüthrich, who is also the Cecil H. & Ida M. Green Professor of Structural Biology at Scripps Research Institute, won the Nobel Prize in Chemistry in 2002 for his development of nuclear magnetic resonance spectroscopy for determining the 3-D structures of biological macromolecules in solution.

NMR spectroscopy, which was first reported in 1946, has played a pivotal role in modern biology and medicine, Wüthrich said in his plenary lecture. He focused his talk on structure determination of proteins such as prions.

"In my own field, the use of solution NMR techniques to study proteins has been pursued at an ever-increasing pace over the past 35 years," he noted. The Wüthrich group has employed NMR techniques to determine the structures of a variety of proteins including small membrane proteins reconstituted in water-soluble micelles.

In another plenary lecture, Jean-Marie Lehn, chemistry professor in the Coll??ge de France at Louis Pasteur University in Strasbourg, discussed complexity and dynamics in chemical systems. Lehn won the Nobel Prize in Chemistry in 1987 for his work on molecular recognition and the development of supramolecular chemistry.

"Chemistry started when, after the Big Bang, the universe became cool enough for molecules to form," he said. "The basic question is: How did matter become complex? The answer is self-organization."

Supramolecular chemistry explores systems undergoing self-organization. Lehn explained that it is intrinsically a dynamic chemistry because of the lability of the noncovalent interactions connecting the molecular components of a supramolecular entity and the resulting ability of the supramolecular species to exchange their constituents reversibly.

These characteristics of supramolecular chemistry are also observed in molecular chemistry when covalent bonds that break and re-form reversibly are introduced into molecules. Molecules with reversible covalent bonds can be used as building blocks to construct combinatorial libraries of molecules in dynamic equilibrium. When a template molecule is introduced to such a library, it selects the best-fitting molecule from the library and uses noncovalent interactions, such as hydrogen bonding, to form a host-guest complex.

Lehn has a name for the chemistry of systems that are dynamic at both the molecular and supramolecular levels. He calls it "constitutional dynamic chemistry," or CDC, and contrasts it with "constitutional static chemistry." The latter relies on explicit programming and self-organization by design to synthesize a desired molecular or supramolecular product. CDC, on the other hand, takes advantage of dynamic diversity to achieve variation and selection.

"The implementation of selection in chemistry introduces a fundamental change in outlook," Lehn observed. "CDC opens the way to adaptive and evolutive chemistry—a kind of Darwinian chemistry."

Mastering complexity is one of the key challenges for chemists, according to Igor Tkatchenko, a director of research at the University of Bourgogne in Dijon, France. He was vice chairman of the French Chemical Society until earlier this year and represented the society at the congress. "But the ultimate challenge lies in tackling problems relating to energy and the environment," he told C&EN.

Geoscientist Paul Crutzen, of Max Planck Institute for Chemistry in Mainz, Germany, and Scripps Institution of Oceanography, painted a frightening picture of the impact of human activities on Earth. "Human activities accelerated over the past few hundred years, creating a new geological era, the 'Anthropocene,' " said Crutzen, who shared the Nobel Prize in Chemistry in 1995 for his work on the formation and decomposition of ozone in the atmosphere.

Over the past three centuries, he noted, the human population has increased to over 6 billion people; industrial output and fish catch have both increased 40-fold; and energy usage, 16-fold. Almost 50% of the land surface has been transformed by human activities. In particular, since World War II, there has been a "great acceleration" in population, water usage, transport, tourism, and many other human activities. "All this has played a major and increasing role in changing the basic properties of the atmosphere and Earth's surface," he observed.

"Human activities are affecting and, in many cases, out-competing natural processes, causing, for instance, the rise of greenhouse gases, which has had an impact on climate, urban and regional air pollution, and consequently on human and ecosystem health," he continued. "We have created chemical instability in the atmosphere. If we do not reduce rising temperatures, we may well cook."

Although tremendous progress has already been made, for example, in reducing emissions of chlorofluorocarbons and consequently ozone depletion, major questions remain and much research needs to be done, Crutzen said. Energy saving, the use of nuclear and renewable forms of energy, and carbon dioxide sequestration will help to reduce the emission of greenhouse gases into the atmosphere, he suggested. "But the tasks are enormous," he added.

One possibility Crutzen and others have proposed for consideration as a last resort, if we cannot reduce global warming by other means, is to fire rockets into the atmosphere to discharge hydrogen sulfide (C&EN, Aug. 7, page 19; Sept. 18, page 13). H₂S would form sulfate particles that could cool our planet in the same way sulfate particles produced by volcanic eruptions do.

George Olah, professor of chemistry and director of the Loker Hydrocarbon Research Institute at the University of Southern California, reminisced about Budapest at the beginning of his plenary lecture. "It is pleasure to be back in my native city, which I left 50 years ago," said Olah, who won the 1994 Nobel Prize in Chemistry for his work on carbocation and hydrocarbon chemistry.

Like Crutzen, his lecture focused on the environment. "Air belongs to everybody," he said in his plenary lecture. "It does not matter who releases CO₂ into the atmosphere. It's an international problem, and we need to find solutions.

"Despite the diminishing resources of nonrenewable fossil fuels and the effect of CO₂ formed from them on global warming, there is a continuing need for hydrocarbons and their derived products," he continued. "Nature gave us hydrocarbons, in the form of oil, coal, natural gas, and other resources, as a great present. But they are not renewable on a human timescale, and we are using them up at a frightening rate."

Olah outlined an approach to solving this problem that relies on methanol. This liquid, he said, can be used as a fuel for internal combustion engines and fuel cells, and it can also be converted to important synthetic hydrocarbons such as ethylene and propylene by catalytic dehydration. The methanol could be produced by direct oxidation of methane in existing supplies of natural gas without resorting to the production of synthesis gas (carbon monoxide and hydrogen) by Fischer-Tropsch chemistry, a process that consumes vast amounts of energy.

But the true methanol economy, as Olah calls it, will not depend on the methane oxidation route. It will rely on the use of hydrogen to reduce CO₂ sequestered from the atmosphere, he said.

Both the oxidation and reduction routes present major scientific and technological challenges. For example, current methods for both routes lead to the formation of formaldehyde and formic acid as by-products and low yields of methanol.

In addition, substantial amounts of energy would be needed to generate sufficient supplies of hydrogen from water to convert CO₂ into methanol. This energy, Olah suggested, could come from safe nuclear power plants as well as alternative energy sources such as sunlight and wind. The selective absorption of CO₂ from the atmosphere is also difficult, he added.

"The methanol economy can free mankind from dependence on diminishing supplies of natural fossil fuels," Olah said. "At the same time, recycling excess CO₂ from the atmosphere will mitigate the man-made effects of global warming."

The Budapest congress also tackled the challenge of enhancing the public's perception of chemistry.

"The image of chemistry is continually worsening all over the world," Náray-Szabó told C&EN. "One reason is the potential environmental threat by the uncontrolled production and use of chemicals."

Tkatchenko added that, although chemistry is a central science, it has poor visibility. "Chemistry should be regarded as a fundamental partner rather than just a service science in its interactions with physics, biology, and other sciences," he said. "Furthermore, we need to bring more youngsters to chemistry."

The Molecular Frontiers Institute, unveiled at the Budapest congress, attempts to address the image problem, particularly in regard to encouraging young people to take an interest in chemistry (C&EN, Sept. 11, page 13). Its activities will include the award of prizes to youngsters 12 to 18 years old who submit the best questions about molecular science.

Youth also featured in another event at the congress, the 2006 European Young Chemist Award. "The award was intended to showcase and recognize the excellent research being carried out by young scientists working in the chemical sciences," explained Bruno Pignataro, chemistry professor at the University of Palermo, Italy. He organized the competition, which was sponsored by the Italian Chemical Society in conjunction with other European chemical societies.

Almost 120 chemists, all of whom participated in the Budapest congress and were under 34 years old, entered the competition. The award was open not just to chemists working in Europe but also to European chemists working outside the European Union. For example, Jasminka Mizdrak, who was born in Croatia and was one of the 14 finalists, is carrying out Ph.D. research on the chemistry of human lens and cataracts at the University of Macquarie, in Sydney, Australia.

The 14 finalists made short presentations of their research during the congress. Jonathan Nitschke, an organic chemist at the University of Geneva, Switzerland, won first prize, which consisted of $2,280, a certificate, and a gold medal with the EuCheMS logo. His group is developing techniques based on the simultaneous formation of covalent and coordinative bonds during the course of a single overall self-assembly process.

"We are learning how to direct this process, enabling us to build structurally complex objects from simple subcomponents," Nitschke told C&EN. "We are also investigating new routes to metal-containing polymers and ways to use self-assembly to complement traditional techniques of organic synthesis."

Two second prizes, each consisting of $1,020, a certificate, and a silver medal with the EuCheMS logo, went to Lee Cronin, a chemistry professor at the University of Glasgow in Scotland, and Javier García-Martínez, who leads the molecular nanotechnology group at the University of Alicante in Spain. In his presentation at the congress, Cronin outlined his recent research on the supramolecular self-assembly of polyoxometalate clusters. GarcÍa-MartÍnez described his work on hierarchical nanostructures prepared by combining biomolecules found in cell membranes and cationic surfactants.

The award jury also gave special mentions to two other finalists: Elisabete Carvalho, a Ph.D. student at the University of Porto in Portugal, and Iryna A. Koval, a recent Ph.D. graduate in chemistry at Leiden University in the Netherlands. Carvalho presented research on the interaction of salivary proteins with grape seed procyanidins. Koval talked about her work at Leiden on the use of synthetic model compounds to unravel the mechanism of the enzymatic cycle of catechol oxidase, an enzyme that is responsible for melanin formation in plant tissues.

Toward the end of the congress, Feast spoke about his vision of chemistry research in Europe. "As chemists, we live in interesting times and face a number of significant challenges that we have to solve if we are to pass the planet on to our grandchildren in a decent state," he said. "These challenges can also be regarded as opportunities for doing useful things for society and creating wealth.

"Society requires us to provide new pharmaceuticals and medical diagnoses, improved methods of food production, and new materials," he continued. "Chemists are also required to monitor and control the fate of chemicals, agrochemicals, and pharmaceuticals; develop renewable sources of energy; and remove and recycle greenhouse gases. In addition, there is a need for clean and energy-efficient methods for the production of chemicals, agrochemicals, and pharmaceuticals using renewable feedstocks."

The chemical sciences will thus play a key role in meeting the scientific, technological, economic, and human challenges of the 21st century, he added. Although these challenges are not unique to Europe, chemists there have the responsibility to help solve them, especially by building up influence and contacts among the public and decisionmakers, he said.

However, if European chemists want to use these congresses to showcase European chemistry and influence public opinion, they will need to get the press on board. Surprisingly, press were not encouraged to cover the congress. Accredited journalists who registered on the congress website received a press badge that entitled them to attend the congress on one day only.

The 2nd European Chemistry Congress will be coorganized by EuCheMS and the Italian Chemical Society. It will take place in Torino, Italy, on Sept. 16-20, 2008.