Achim Müller Explained

Achim Müller
Birth Date:	14 February 1938
Birth Place:	Detmold, Gau Westphalia-North, Germany
Field:	Chemistry, Nanoscience
Work Institution:	University of Bielefeld
Alma Mater:	University of Göttingen
Known For:	Tailor-made porous nanoclusters and their use as versatile materials

Achim Müller (14 February 1938 – 28 February 2024) was a German chemist. He was Professor Emeritus at the Faculty of Chemistry, University of Bielefeld.

His research involved mainly the chemistry of transition metals, especially with relation to nanochemistry.^{[1] [2] [3] [4] [5] [6] [7]}

His later research related mainly to the synthesis of spherical porous metal oxide nanocapsules Mo₁₃₂ Keplerates. Müller also worked on simple transition metal sulphur compounds, including related hydrodesulfurization catalysis and a new type of host guest chemistry based on polyoxovanadates He had also strong interest in history and philosophy of science.^[8]

Academic career

Achim Müller studied chemistry and physics at the University of Göttingen and received there his PhD degree (1965) and the Habilitation (1967). In 1971, he became professor at the University of Dortmund and in 1977 professor of Inorganic Chemistry at the University of Bielefeld. In 2006 he was awarded the Manchot-Forschungsprofessur of the Technische Universität München.

Müller was a member of the German Academy of Sciences Leopoldina,^[9] Polish Academy of Sciences, The Indian National Science Academy, National Academy of Exact Physical and Natural Sciences in Argentina, and Academia Europaea. He has received honorary degrees from the Russian Academy of Sciences (RAS) and the Université Pierre et Marie Curie, Paris as well as the “Profesor Honorario“ of the National University of La Plata. He has also received the Alfred Stock Memorial Prize 2000, Prix Gay-Lussac/Humboldt 2001, Sir Geoffrey Wilkinson Prize 2001, and the Centenary Medal of the Royal Society of Chemistry 2008/9, London.^[10] In 2012 he was awarded the prestigious Advanced Grant by the European Research Council (ERC). He was an Honorary Fellow of the Chemical Research Society of India.

Research

His later research related mainly to bottom-up pathways towards tailor-made spherical porous metal oxide nanocapsules Mo₁₃₂ Keplerates. Müller's discovery of the molecular giant spheres (Keplerates) of the type Mo₁₃₂ (diameter ca. 3 nm) and their derivatives,^[11] of the wheel shaped cluster Mo₁₅₄ (Refs. and ^{[12] [13] [14]}) and hedgehog shaped cluster Mo₃₆₈ (as large as 6 nm) has caused a paradigm shift due to the unique structural features and huge application range of these molecular nanoclusters .

The capsule has 20 well-defined pores with crown-ether functions which may be reversibly opened and closed. Substrates enter through these pores, and they can react to form a variety of species depending on the internal tapestry of the nanocontainer. This inorganic nanocell also allows ion transport through the cavity. Several new phenomena under confined conditions can be studied by variation of the internal ligands with hydrophilic and/or hydrophobic character, based on a variety of reactive substrates inside (for the interdisciplinary character of the whole compound class see Ref.^[15]). These single molecules are quite large; this can be shown by taking the length of an oxygen molecule with two atoms (length 0.12 nm) as a unit, then considering Mo₃₆₈ which is 50 times larger.

All the mentioned nanomaterials belong to a class commonly termed polyoxometalates and some special ones to the molybdenum blue family; the elucidation by Müller of the chemical nature of molybdenum blue was a real tour de force.^{[16] [17]}

There are two older synthetic topics where Achim Müller did pioneering work. This refers to basic simple transition metal sulphur compounds, including related hydrodesulfurization catalysis and a new type of host guest chemistry based on polyoxovanadates (for both topics see especially the three Honorary Issues under Bibliography). One paper about polyoxometalates was cited ca. 2000 times.^[18] The publications of Achim Müller were highlighted many times in the media and related magazines.^[19] Important last sentences: “Giant polyoxometalates (POMs) are of particular interest, as they are the largest inorganic molecules ever made, combined with fascinating structures and manifold applications in catalysis, medicine and material sciences. Typically, Müller‘s group has achieved great success in creating giant polyoxomolybdates (POMos) during the past two decades, establishing a series of incredibly large POMos with hundreds of Mo centers, such as,,, and . Especially, with more than 360 Mo atoms, still is the largest POM to date...“^[20]

Applications and impact

These are soluble in water and are very probably one of the most versatile materials regarding applications in nanoscience.It is evident that such applications are of interest not only for chemistry but also for biology, supramolecular chemistry and materials science as well as discrete mathematics.The applications include the following topics:

• Investigating processes, including catalytic ones, under confined conditions, especially in capsules with stepwise tunable pores and tunable internal functions
• Coordination chemistry at surfaces, in pores and in cavities of nanocapsules: sphere-surface supramolecular chemistry, controlled exchange of guests at different internal sites with each other and with the outside, nano ion-chromatography, nucleation processes under confined conditions
• Modelling ion transport across transmembrane channels
• New insights into hydrophobic interactions, e.g. thermodynamics of hydrophobic clustering, sequestration of hydrophobic organic pollutants, and nano-dewetting
• Structure and dynamics of encapsulated high and low density water
• Towards multifunctionality and hierarchical complexity: examples for chemical adaptability and for a supramolecular chemical Darwinism, self-assembly of capsules into various patterns in different phases (e.g. blackberry-like hollow spherical assemblies as well as two- and three-dimensional structures)

Müller's related work shows many applications (see above), for example, how cellular processes like ion-transport can be modelled based on the spherical porous capsules^{[21] [22]} and how the latter can be used to remove toxic compounds from water.^[23]

The compounds are studied worldwide by many groups especially in relation to potential applications in Materials Science (see Ref. and below). One aspect is modelling of the Lotus effect,^[24] another one is chemical adaptability as a new phenomenon.^[25]

An interesting mathematical treatment of the Keplerates could be developed in relation to spherical viruses and Buckminster Fuller Domes based on Archimedean and Platonic solids.^[26] The unique range of potential applications of the Mo₁₃₂ Keplerates has also been highlighted by several other authors, e.g.:^[27] "Thus, Keplerate-type capsules represent unique supramolecular objects offering a tunable spatially-restricted environment and promising in many domains such as catalysis, electric conductivity, non-linear optics, liquid crystals, vesicles and "blackberry" aggregates. ...a key point to promote confined space engineering." In another publication^[28] it is written: "Initiated and led by Müller and co-workers, the synthesis and structural characterization of protein-sized metal oxide clusters (2-6 nm) have generated great interest in the areas of physics, biology, chemistry, and materials science"; see also regarding a similar comment Ref.^[29] Some of the clusters can be obtained by planned synthesis,^[30] while the related derivative (also because of the structure of a Keplerate^[31]) Mo₇₂Fe₃₀ has unique magnetic properties.

Personal life and death

Müller enjoyed ancient Greek philosophy, classical music, and mountain hiking. He had a passion for woodland birds from his early childhood, a pastime which his father cherished also.

Achim Müller died on 28 February 2024, at the age of 86.^[32]

Bibliography

• Honorary Issue of Inorganica Chimica Acta (Biography) with a dedication by E. Diemann and B. Krebs, 2010, 363, 4145.
• Honorary Issue of Journal Cluster Science with Foreword by M. T. Pope, 2003, 14, 189.
• Honorary Issue of Journal of Molecular Structure with a Dedication by A. J. Barnes, E. Diemann, and H. Ratajczak, 2003, 656, 1.
• Prof. Achim Müller awarded 2001 Sir Geoffrey Wilkinson Prize, S. Migchielsen, G. Férey, Solid State Sciences, 2002, 4, 753 https://doi.org/10.1016/S1293-2558(02)01335-3; past winners include: M. F. Hawthorne (1993), F. A. Cotton (1995), Lord Jack Lewis (1997).
• In a section about Achim Müller of F. A Cotton's book (pp 310/11): My Life in the Golden Age of Chemistry: More Fun Than Fun, the author writes: “'The Most Unforgetable Character I Have Met.' For me Achim Müller could be that man."

See also the following titles:

• Cronin . Leroy . Inorganic Molecular Capsules: From Structure to Function . Angewandte Chemie International Edition . Wiley . 45 . 22 . 26 May 2006 . 1433-7851 . 10.1002/anie.200600090 . 3576–3578. 16683287 .
• Müller . Achim . Bringing inorganic chemistry to life . Chemical Communications . Royal Society of Chemistry (RSC) . 7 . 24 March 2003 . 1359-7345 . 10.1039/b300207c . 803–806.
• Achim Müller . Angewandte Chemie International Edition . Wiley . 52 . 3 . 2 January 2013 . 1433-7851 . 10.1002/anie.201209135 . 800–802. 23283763 . Müller . A. .
• See additionally Reference 16 b) l’actualité chimique.

External links

• Web site: Achim Müller Bielefeld . Uni Bielefeld . de . 23 July 2023.

Notes and References

1. Müller . Achim . Gouzerh . Pierre . From linking of metal-oxide building blocks in a dynamic library to giant clusters with unique properties and towards adaptive chemistry . Chemical Society Reviews . 2012 . 41 . 22 . 7431–63 . 10.1039/C2CS35169B . 22948798 .
2. Müller . Achim . Gouzerh . Pierre . Capsules with Highly Active Pores and Interiors: Versatile Platforms at the Nanoscale . Chemistry - A European Journal . 22 April 2014 . 20 . 17 . 4862–4873 . 10.1002/chem.201305010 . 24644235 .
3. Müller . Achim . Reuter . Hans . Dillinger . Stephan . Supramolecular Inorganic Chemistry: Small Guests in Small and Large Hosts . Angewandte Chemie International Edition in English . 17 November 1995 . 34 . 21 . 2328–2361 . 10.1002/anie.199523281 .
4. DAY . VICTOR W. . KLEMPERER . WALTER G. . YAGHI . OMAR M. . Induced molecule self-organization . Nature . July 1991 . 352 . 6331 . 115–116 . 10.1038/352115c0 . 1991Natur.352..115D . 45122433 .
5. Müller . A. . Supramolecular inorganic species: An expedition into a fascinating, rather unknown land mesoscopia with interdisciplinary expectations and discoveries . Journal of Molecular Structure . September 1994 . 325 . 1 . 13–35 . 10.1016/0022-2860(94)80014-6 . 1994JMoSt.325...13M .
6. Rohmer . Marie-Madeleine . Bénard . Marc . Blaudeau . Jean-Philippe . Maestre . Juan-M . Poblet . Josep-M . From Lindqvist and Keggin ions to electronically inverse hosts . Coordination Chemistry Reviews . December 1998 . 178-180 . 1019–1049 . 10.1016/S0010-8545(98)00162-3 .
7. Müller’s work on a new type of isopolyoxovanadates has provided some of the most instructive examples of host-guest inorganic chemistry, leading to the recognition that a polyoxometalate is a supramolecular species involving a negatively charged host cage and a negatively charged encapsulated guest, and hence opening a new era in polyoxometalate chemistry. The template self-organization of an ”electronically inverse host” around a negatively charged guest might seem somewhat puzzling: According to theoretical studies, this follows from the fact that electrostatic repulsion is overcome by maximizing the molecular electrostatic potential at the guest
8. For example: a) Die inhärente Potentialität materieller (chemischer) Systeme, A. Müller, Philosophia naturalis, 1998, Bd. 35, Heft 2, 333; b) Naturgesetzlichkeiten – Chemie lediglich ein Bereich zwischen Physik und biologischem Geschehen? A. Müller, Philosophia naturalis, 2000, Bd. 37, Heft 2, 351; c) Chemie und Ästhetik - die Formenvielfalt der Natur als Ausdruck ihrer Kreativität, A. Müller, ZiF (Center for Interdisciplinary Research), Mitteilungen, 1999, 4, 7; d) Science, Society, and Hopes of a Renaissance Utopist, A. Müller, Science & Society, 2000, 1, 23.
9. Web site: List of Members . Nationale Akademie der Wissenschaften Leopoldina . 29 June 2023 . 23 July 2023.
10. Web site: Centenary Lectureship Winner 2008/09. www.rsc.org.
11. Garai . Somenath . Haupt . Erhard T. K. . Bögge . Hartmut . Merca . Alice . Müller . Achim . Picking up 30 CO₂ Molecules by a Porous Metal Oxide Capsule Based on the Same Number of Receptors . Angewandte Chemie . 15 October 2012 . 124 . 42 . 10680–10683 . 10.1002/ange.201204089 . 2012AngCh.12410680G .
12. Liu . Tianbo . Diemann . Ekkehard . Li . Huilin . Dress . Andreas W. M. . Müller . Achim . Self-assembly in aqueous solution of wheel-shaped Mo154 oxide clusters into vesicles . Nature . 6 November 2003 . 426 . 6962 . 59–62 . 10.1038/nature02036 . 14603315 . 2003Natur.426...59L . 4430852 .
13. Müller . Achim . Diemann . Ekkehard . Kuhlmann . Christoph . Eimer . Wolfgang . Serain . Claire . Tak . Thomas . Knöchel . Arndt . Pranzas . P. Klaus . Hierarchic patterning: architectures beyond 'giant molecular wheels' . Chemical Communications . 2001 . 19 . 1928–1929 . 10.1039/B103639B . 12240223 .
14. Polyoxomolybdate Clusters: Giant Wheels and Balls, A. Müller, S. K. Das, E. Krickemeyer, C. Kuhlmann (checked by: M. Sadakane, M. H. Dickman, M. T. Pope), Inorganic Syntheses, Editor J. R. Shapley, 2004, 34, 191.
15. Molecular growth from a Mo₁₇₆ to a Mo₂₄₈ cluster, A. Müller, S. Q. N. Shah, H. Bögge, M. Schmidtmann, Nature, 1999, 397, 48.
16. Soluble Molybdenum blues - "des Pudels Kern", A. Müller, C. Serain, Acc. Chem. Res., 2000, 33, 2.
17. a) A Nanosized Molybdenum Oxide Wheel with a Unique Electronic-Necklace Structure: STM Study with Submolecular Resolution, D. Zhong, F. L. Sousa, A. Müller, L. Chi, H. Fuchs, Angew. Chem. Int. Ed., 2011, 50, 7018; b) From Scheele and Berzelius to Müller: Polyoxometalates (POMs) revisited and the "missing link" between the bottom up and top down approaches, P. Gouzerh, M. Che, l’actualité chimique, 2006, June Issue, No. 298, 9.
18. Polyoxometalate Chemistry: An Old Field with New Dimensions in Several Disciplines, M. T. Pope, A. Müller, Angew. Chem. Int. Ed. Engl., 1991, 30, 34.
19. Like Frankfurter Allgemeine Zeitung, Die Welt, Süddeutsche Zeitung, Neue Zürcher Zeitung, Handelsblatt, Göttinger Tagesblatt, The Hindu, El Pais, Gazeta Wyborcza, Situs Kimia Indonesia, Times of India, Science in Siberia, Scientific American, American Mathematical Society, New Scientist, Chemistry World, Chemistry in Britain, Materials Today, Spektrum der Wissenschaft, Bild der Wissenschaft, Naturwissenschaftliche Rundschau, Chem. i. u. Zeit, La Recherche, Der Spiegel. For details see http://www.uni-bielefeld.de/chemie/emeriti/ac1-mueller/ and Reference 6 c) Mitteilungen .
20. Wu . Yan-Lan . Li . Xin-Xiong . Qi . Yan-Jie . Yu . Hao . Jin . Lu . Zheng . Shou-Tian .

    A Macromolecular Polyoxometalate with Close to 300 Niobium Atoms

    . Angewandte Chemie International Edition . Wiley . 57 . 28 . 14 June 2018 . 1433-7851 . 10.1002/anie.201804088 . 8572–8576. 29809317 . 44101110 .
21. Petina . Olga . Rehder . Dieter . Haupt . Erhard T. K. . Grego . Alina . Weinstock . Ira A. . Merca . Alice . Bögge . Hartmut . Szakács . Julia . Müller . Achim . Guests on Different Internal Capsule Sites Exchange with Each Other and with the Outside . Angewandte Chemie International Edition . Wiley . 50 . 2 . 5 December 2010 . 1433-7851 . 10.1002/anie.201005596 . 410–414. 21132826 .
22. Merca . Alice . Haupt . Erhard T. K. . Mitra . Tamoghna . Bögge . Hartmut . Rehder . Dieter . Müller . Achim . Mimicking Biological Cation-Transport Based on Sphere-Surface Supramolecular Chemistry: Simultaneous Interaction of Porous Capsules with Molecular Plugs and Passing Cations . Chemistry - A European Journal . Wiley . 13 . 27 . 17 September 2007 . 0947-6539 . 10.1002/chem.200700294 . 7650–7658. 17639541 . free .
23. a) * Schäffer . Christian . Todea . Ana Maria . Bögge . Hartmut . Petina . Olga A. . Rehder . Dieter . Haupt . Erhard T. K. . Müller . Achim . Hydrophobic Interactions and Clustering in a Porous Capsule: Option to Remove Hydrophobic Materials from Water . Chemistry - A European Journal . Wiley . 17 . 35 . 11 July 2011 . 0947-6539 . 10.1002/chem.201101454 . 9634–9639. 21748814 . b) Garai . Somenath . Bögge . Hartmut . Merca . Alice . Petina . Olga A. . Grego . Alina . Gouzerh . Pierre . Haupt . Erhard T. K. . Weinstock . Ira A. . Müller . Achim . Densely Packed Hydrophobic Clustering: Encapsulated Valerates Form a High-Temperature-Stable Capsule System . Angewandte Chemie International Edition . Wiley . 55 . 23 . 3 May 2016 . 1433-7851 . 10.1002/anie.201601140 . 6634–6637. 27140207 . (front cover picture).
24. Müller . Achim . Garai . Somenath . Schäffer . Christian . Merca . Alice . Bögge . Hartmut . Al-Karawi . Ahmed Jasim M. . Prasad . Thazhe Kootteri . Water Repellency in Hydrophobic Nanocapsules-Molecular View on Dewetting . Chemistry - A European Journal . Wiley . 20 . 22 . 29 April 2014 . 0947-6539 . 10.1002/chem.201402986 . 6659–6664. 24782303 . free .
25. Müller . Achim . Merca . Alice . Al-Karawi . Ahmed Jasim M. . Garai . Somenath . Bögge . Hartmut . Hou . Guangfeng . Wu . Lixin . Haupt . Erhard T. K. . Rehder . Dieter . Haso . Fadi . Liu . Tianbo . Chemical Adaptability: The Integration of Different Kinds of Matter into Giant Molecular Metal Oxides . Chemistry - A European Journal . Wiley . 18 . 51 . 23 November 2012 . 0947-6539 . 10.1002/chem.201203186 . 16310–16318. 23180718 .
26. a) Book: Delgado . O. . Dress . A. . Müller . A. . Polyoxometalate Chemistry From Topology via Self-Assembly to Applications . Spherical (Icosahedral) Objects in Nature and Deliberately Constructable Molecular Keplerates: Structural and Topological Aspects . 2002 . Kluwer Academic Publishers . Dordrecht . 0-7923-7011-2 . 10.1007/0-306-47625-8_6 . 69–87. b) Müller . Achim . A chemist finds beauty in molecules that resemble an early model of the Solar System . Nature . 447 . 2007 . 0028-0836 . de . 23 July 2023. c) Müller . Achim . The beauty of symmetry . Science . 300 . 5620 . 2003 . 749–750 . 10.1126/science.1084991 . 12730586 . 98108174 . 0036-8075 . de . 23 July 2023.
27. Lai . Thanh-Loan . Awada . Mouhamad . Floquet . Sébastien . Roch-Marchal . Catherine . Watfa . Nancy . Marrot . Jérôme . Haouas . Mohamed . Taulelle . Francis . Cadot . Emmanuel . Tunable Keplerate Type-Cluster "Mo₁₃₂" Cavity with Dicarboxylate Anions . Chemistry - A European Journal . Wiley . 21 . 38 . 29 July 2015 . 0947-6539 . 10.1002/chem.201406648 . 13311–13320. 26224211 .
28. Yin . Panchao . Wu . Bin . Li . Tao . Bonnesen . Peter V. . Hong . Kunlun . Seifert . Soenke . Porcar . Lionel . Do . Changwoo . Keum . Jong Kahk . Reduction-Triggered Self-Assembly of Nanoscale Molybdenum Oxide Molecular Clusters . Journal of the American Chemical Society . American Chemical Society (ACS) . 138 . 33 . 8 August 2016 . 0002-7863 . 10.1021/jacs.6b05882 . 10623–10629. 27459601 . 1324096 .
29. Yin . Panchao . Wu . Bin . Mamontov . Eugene . Daemen . Luke L. . Cheng . Yongqiang . Li . Tao . Seifert . Soenke . Hong . Kunlun . Bonnesen . Peter V. . Keum . Jong Kahk . Ramirez-Cuesta . Anibal J. . X-ray and Neutron Scattering Study of the Formation of Core–Shell-Type Polyoxometalates . Journal of the American Chemical Society . American Chemical Society (ACS) . 138 . 8 . 18 February 2016 . 0002-7863 . 10.1021/jacs.5b11465 . 2638–2643. 26848596 . 1240563 .
30. Schäffer . Christian . Todea . Ana Maria . Gouzerh . Pierre . Müller . Achim . Spontaneous self-assembly of a giant spherical metal-oxide Keplerate: addition of one building block induces "immediate" formation of the complementary one from a constitutional dynamic library . Chem. Commun. . Royal Society of Chemistry (RSC) . 48 . 3 . 2012 . 1359-7345 . 10.1039/c1cc15907k . 350–352. 22038273 .
31. a) Kögerler . Paul . Tsukerblat . Boris . Müller . Achim . Structure-related frustrated magnetism of nanosized polyoxometalates: aesthetics and properties in harmony . Dalton Trans. . Royal Society of Chemistry (RSC) . 39 . 1 . 2010 . 1477-9226 . 10.1039/b910716a . 21–36. 20023927 . b) Book: Gatteschi . Dante . Sessoli . Roberta . Villain . Jacques . Molecular Nanomagnets . Oxford University Press . 2 March 2006 . 978-0-19-856753-0 . 10.1093/acprof:oso/9780198567530.001.0001.
32. Web site: Achim Müller (1938 – 2024) . Chemistry Views . 10 March 2024.