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takes note of exciting developmentsand is keen to get involved. A case inpoint occurred while he was a doc-toral student at Purdue University inIndiana (USA), focusing on the man-ufacture and spectroscopic charac-terization of self-organizing mono-molecular layers. Jean-Marie Lehnvisited the institute to give a lectureon supramolecular chemistry. Evenbeforehand, after reading an articlein the German-language magazineANGEWANDTE CHEMIE, Dirk G. Kurthwas fascinated by the world of weakinteraction revealed by Lehn, winnerof the 1987 Nobel Prize for chem-istry.

The concepts and ideas, the shearpotential offered by hydrogen bond-ing and similar intermolecular forceshad him in their grip. And whenKurth listened to Lehn’s lecture, hewas convinced that he wanted tospend his postdoctoral time withLehn. The two men spoke, and inJune 1994, Kurth found himself inStrasbourg. He spent just under twoyears at the Université Louis Pasteur– a time that he describes as fruit-ful and formative. “The atmospherethere was unique. Everything wasinternationally oriented. There were20 of us welded into a team in next to no time.” Dirk G. Kurth hasfond memories of stimulating dis-cussions with his colleagues. Jean-Marie Lehn himself regularly visitedthe laboratories, was always well in-formed, and had something to add toevery conversation – be it technicalor social.

In terms of the intellectual benefits,says Kurth, his time in France wasthe richest in his career to date –even if Albuquerque, New Mexico,where he spent his first year and ahalf in the U.S. in 1989/90, scores

For 40 days a year he finds himself immersed in another culture. DIRK G. KURTH

from the MAX PLANCK INSTITUTE OF COLLOIDS AND INTERFACES in Potsdam

spends part of his working life as the youngest – and the first foreign – Director at

the NATIONAL INSTITUTE FOR MATERIAL SCIENCE in Tsukuba, Japan.

His task there is to develop a department specializing in “supramolecular functional

materials” – a challenge that requires more than just a knack for science.

In the course of their search, theJapanese took notice of the GermanMax Planck researcher. It’s not hardto guess why. More than 70 publica-tions attest to his scientific creativi-ty, and the time he has already spentabroad in the U.S. and France showsthat he is quite at home anywhere inthe world, and keen to experiencenew things. Following their visit toPotsdam, the Japanese delegationwere convinced not just that he wasprofessionally qualified, but alsothat Kurth would cope admirablywell in their country. His friendlypersonality, quiet manner and openacceptance of other traditions allstand him in good stead.

DREAM OFFER

FROM THE FAR EAST

“The offer from Japan was irre-sistible – simply fantastic,” saysKurth. With a budget of around twomillion euros, over the next threeyears he will be able to establish adepartment for supramolecular func-tional materials. Dirk G. Kurthspends about 40 days per year inJapan, developing and implementingnew ideas together with NIMS re-searchers. The rest of his time isspent at his home institute in Ger-many. In the absence of the Director,the day-to-day business in Japan ishandled by a deputy who also makesregular visits to the Max Planck In-stitute in Potsdam for discussions,planning meetings and scientific ac-tivities. It is likely that he himselfwill one day become a Director.

Even while he was a student, Kurthhad made up his mind to write hisdissertation in America. However, acloser look reveals that, for all of hismeticulous planning, he always re-mains open to new challenges. He

“Ihope I can bring some of thefriendly and relaxed atmos-

phere back to Germany with me.”The mindset that Dirk G. Kurth, achemist at the Max Planck Instituteof Colloids and Interfaces in Pots-dam, encounters daily in Japan hasmade a deep impression on him. Heis just back from his third trip to the“land of the rising sun.” Raised voic-es are rare, he says, and aggressive-ness unknown. The reason thatKurth is able to gather these andother experiences lies in the factthat, at present, Potsdam is not theonly place he calls home. He is alsoresearching at Japan’s NIMS (Na-tional Institute for Material Science)in the scientific city of Tsukuba,northeast of Tokyo. At the age of 40,he is the youngest, and above all, thefirst foreign Director to be appointedthere.

Dirk G. Kurth is justly proud – heknows, after all, what the NIMSmeans to the Japanese. He describesthe situation thus: “They aim to bethe world’s number one. So threeyears ago, they embarked on a majorrestructuring program to amalga-mate several institutes. The resultwas NIMS, which Japan hopes will take a leading position in thematerial sciences.” What’s more:“When the Japanese put somethingon the political agenda, they see itthrough.” The Japanese strategy, asKurth describes it, is to look farahead into the future, identify newkey technologies and focal points forresearch, and then create the infra-structure needed to do the job. An-other element is a desire to be moreopen on an international front,which includes bringing the best sci-entists to Japan, and with them, therequisite know-how.

Dirk G. KurthDirk G. KurthPERSONAL Portrait

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The supramolecular modules synthesized by the group headed by Dirk G. Kurth spontaneously arrange

themselves as nano-rods on a graphite surface.

NANOtechnologyPERSONAL Portrait

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highest for its landscape and qualityof life. “But it was in Strasbourg thatI learned to think in entirely newways. I discovered how to designmolecules, what forces and interac-tions you can use, and that the pointis always to keep the syntheses ofthese molecules as simple as possi-ble.” Today Kurth, who began hisstudy of chemistry in Cologne, usesthis knowledge to produce supra-molecular self-generating structures.

As the head of his own workinggroup at the Max Planck Institute ofColloids and Interfaces, he has longsince become an idea-man. The factthat he is not now himself an inhab-itant of the laboratory is somethinghe no longer misses. “In those days,in America, when I was heavily in-volved with spectroscopy and otheroptical methods – in other wordsphysics – I missed the chemical lab-oratory work. But in Strasbourg Iwas able to really indulge myselfwith synthetic chemistry.” Cre-ativity in the laboratory was apowerful experience, he says. Ashead of a research group, henow enjoys discussions with hisstudents, post-graduates and post-docs, developing, coordinating and

implementing new ideas. His ownexperiences in the laboratory comein very handy. As do the lectures hegives in his capacity as external lec-turer at the University of Potsdam.

RESEARCHERS PLAY

MOLECULAR LEGOS

When asked to describe what he andhis colleagues and partners actuallydo, Kurth resorts to the term “molec-ular Legos.” After all, “it’s like join-ing little building blocks together toform larger structures. But the bestpart is that the molecules do this oftheir own accord. We design themolecules and construct the interac-tions so that the individual bricksorganize themselves into complex

architectures.” All the chemists haveto do is select suitable molecules andcreate the right conditions, for ex-ample by choosing the concentra-tions of individual building blocks.

Since 1996, Kurth has found theideal conditions for his scientificwork at the Max Planck Institute ofColloids and Interfaces, in the de-partment headed by Helmuth Möh-wald. The ideas behind this molecu-lar Lego game, which Dirk G. Kurthbrought with him from Strasbourg,convinced Möhwald, himself aphysicist, to support a post-doctoralchemist on his way to becoming aprofessor. Their interdisciplinary co-operation, which has endured forsome eight years, might well be de-scribed as waving a chemical magicwand and using physics to investi-gate the results.

At the heart of the functional ma-terials that Kurth creates, there arealways metal ions that form complexcombinations with various organicligands. His team has, for example,been successful with so-called bis-terpyridines. These ligands were firstdescribed in 1991/92 by the Britishchemist Edwin Constable. Dirk G.Kurth found these ligands appealingand became the first to use them tobuild macromolecular functionalunits. “The ligand is neutral, themetal ion is charged, and we use thisto create water-soluble polyelec-trolytes,” says Kurth. The polyelec-trolytes can then be precipitated atinterfaces. The results include mono-layers, Langmuir-Blodgett films,nanostructures, liquid crystallinephases and other architectures thatcould also have interesting nano-technological applications. Today,

the Max Planck researchers, to-gether with their cooperationpartners, have access to a whole

repertoire of methods that enablethem to build such structures.

And because the individualbuilding blocks are held together

scribes the recent occasion whenSpanish post-doc Jesús PitarchLópez discovered something totallynew and unexpected: a kind of“molecular selection.” This is a sys-tem comprising two different ligandsand one metal ion that, in solution,forms three different complexes.However, only one compound crys-tallizes out of the solution. “Onespecies sorts itself out of the mix-ture,” explains Kurth, “as if we hadinstructed the molecules to produceonly one product. And what’s more,it is the most interesting of the threecompounds.” In further experiments,however, it was initially impossibleto replicate these measurements.That, too, is part of everyday re-search life.

“THE JAPANESE ARE

EXTREMELY SUCCESSFUL”

When Dirk G. Kurth first began tostudy chemistry in Cologne in 1984,he found a job during semesterbreaks at Bayer Leverkusen, wherehe became engrossed in technicalchemistry and the idea of transfer-ring laboratory-scale processes tohuge plants. In order to study tech-nical chemistry, he switched to theRWTH, a specialist technical collegein Aachen. It was there that he was

only by weak interaction, some ofthe properties of the resulting func-tional materials appear to be verypromising. In response to externalstimuli, they can change their struc-ture or function and adapt to theirenvironment. This opens the way forentirely new technologies – for in-stance, materials that can heal them-selves. The spectrum of possibilitiesis unlimited, says Kurth, offeringsomething for everyone. The use ofweak intermolecular interaction tobuild functional materials has thusdeveloped into the guiding principleof nanoscience and chemical materi-al research in recent years.

Since obtaining his doctorate andpursuing his postdoctoral studies,Dirk G. Kurth has succeeded in doingwhat he set out to do: combinesupramolecular chemistry and thepossibilities it offers with what helearned in America while manufac-turing and characterizing thin films.“The numerous structures that canbe created by weak interaction alsooffer a host of fascinating physicalproperties,” he concludes. Elec-trochromic, photochromic and mag-netic properties, for example – not tomention catalytic and sensory func-tions. “It is clear at least that thestructures are not only important forbasic research, but also that theymight well have direct applications.”

It is this broad spectrum of poten-tial that fills Dirk G. Kurth with en-thusiasm. And he promptly showsgreat delight when talking about hiswork – for example, when he de-

first gripped by a fascination for ba-sic research – a grip that, to this day,has not loosened. He has alreadyheld a professorship for more than ayear now.

The fact that a Director is treatedalmost like a king in Japan takessome getting used to but, he admitswith a grin, so much attention is notentirely unenjoyable. “Even if I amthe kind of person who prefers flathierarchies – such as those at theMax Planck Institute,” he adds. InJapan, on the other hand, it is hierar-chical differentiation that defines so-cial interaction. No one sits until theDirector has taken his seat. Andwhen he leaves an event, everyoneleaves. Of course, says Kurth, his col-leagues in Japan are pleased by anyefforts to adopt their manners. Buttheir calm composure remains unruf-fled by a failure to remember all ofthe subtleties of Japanese etiquette –harmony is, after all, the primary ob-jective. On the other hand, “TheJapanese, for all their finely graduat-ed social organization, are extremelysuccessful,” says Kurth. One morereason, then, to devote time and at-tention to the country and its way oflife in order to understand the Japan-ese secret to success and bring someof that understanding back home.

INA HELMS

A team player by nature and a scientist by conviction: Dirk G. Kurth of the Max Planck Institute of Colloids and Interfaces with laboratory technician Anne Heilig, working with the scanning force microscope.

Simple but complex: The interaction between inorganic and organic molecules that spontaneously organize themselves into highly structured mesophases with interesting magnetic properties.

The functional unit, a polyoxo-metalate cluster (left), is formed by the spontaneous amalgamation of molecular sub-units. Integrated into a thin film between two transparent electrodes, a window is created which, with the application of an electric voltage, can change color fromtransparent to deep blue (right).

Scientists use computer calculations

to model molecular structures such as this polyoxometalate cluster.

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