We are an interdisciplinary group of scientists and engineers who think big and build small.
Hyejin Kwon, Postdoc
Hyejin received her BS and MS degrees in Chemistry from Sogang University in South Korea and a PhD in Materials Chemistry from the University of Maryland-College Park (2016), under the guidance of Professor YuHaung Wang, where she intensively investigated the photophysical properties of carbon-based semiconducting nanomaterials. She joined CU Boulder after working at Samsung as a Senior Engineer from 2016 to 2018.
Jesse Butterfield, PhD Student
Jesse received his BS in mechanical engineering from the University of Washington in 2013 with a focus on nanoscience and molecular engineering. He spent two years as an engineer for Boeing Commercial Airplanes before joining the Department of Mechanical Engineering at CU Boulder to pursue his PhD.
Karan Dikshit, PhD Student
Karan completed his undergraduate education in polymer engineering in 2014 at the University of Pune, India. He served in different roles in academia and industry before joining the Materials Science and Engineering PhD program at CU Boulder.
Kailey Shara, PhD Student
Originally from Montreal, Canada, Kailey studied both chemistry and electrical engineering at Case Western Reserve University before joining the ATLAS Institute in 2018 to pursue her PhD. Her current research focus includes the synthesis of artificial molecular machines, as well as engineering systems for laboratory automation.
Purnendu, PhD Student
Purnendu holds an MS degree in physics (specialization in material science) from the Indian Institute of Technology (IIT) Roorkee. He has co-founded a graphene nanotechnology company in India and a multidisciplinary design studio at IIT Roorkee. He completed human-computer interaction internships at the Max Planck Institute for Informatics and Bauhaus University, Germany. Purnendu is co-advised by Daniel Leithinger in ATLAS.
The Mechanical Bond
Prior to CU
Sluysmans, D.; Hubert, S.; Bruns, C. J.; Zhu, Z.; Stoddart, J. F.; Duwez, A.-S. Synthetic Oligorotaxanes Exert High Forces When Folding Under Mechanical Load. Nature Nanotech. 2018, 13, 209–213.
Sluysmans, D.; Devaux, F.; Bruns, C. J.; Stoddart, J. F.; Duwez, A.-S. Dynamic Force Spectroscopy of Synthetic Oligorotaxane Foldamers. Proc. Natl. Acad. Sci. U.S.A. 2018, 115, 9362–9366.
Loser, S.; Lou, S. J.; Savoie, B. M.; Bruns, C. J.; Timalsina, A.; Leonardi, M. J.; Harschneck, T.; Turrisi, R.; Zhou, N.; Stern, C. L.; Sarjeant, A. A.; Facchetti, A.; Chang, R. P. H.; Stupp, S. I.; Ratner, M. A.; Chen, L. X.; Marks, T. J. Systematic Evaluation of Structure-Property Relationships in Heteroacene-Diketopyrrolopyrrole Molecular Donors for Organic Solar Cells. J. Mater. Chem. A 2017, 5, 9217–9232.
Slack, C. C.; Finbloom, J. A.; Jeong, K.; Bruns, C. J.; Wemmer, D. B.; Pines, A.; Francis, M. B. Rotaxane Probes for Protease Detection by 129Xe HyperCEST NMR. Chem. Commun. 2017, 53, 1076–1079.
Bruns, C. J.; Liu, H.; Francis, M. B. Near-Quantitative Aqueous Synthesis of Rotaxanes via Bioconjugation to Oligopeptides and Proteins. J. Am. Chem. Soc. 2016, 138, 15307–15310.
Finbloom, J. A.; Slack, C. C.; Bruns, C. J.; Jeong, K.; Wemmer, D. E.; Pines, A.; Francis, M. B. Rotaxane-Mediated Suppression and Activation of Cucurbituril for Molecular Detection by 129Xe HyperCEST NMR. Chem. Commun. 2016, 52, 3119–3122.
Aytun, T.; Santos, P. J.; Bruns, C. J.; Huang, D.; Koltonow, A. R.; Olvera de la Cruz, M.; Stupp, S. I. Self-Assembling Tripodal Small-Molecule Donors for Bulk Heterojunction Solar Cells. J. Phys. Chem. C 2016, 120, 3602–3611.
Hou, X.*; Ke, C.*; Bruns, C.; McGonigal, P. R.; Pettman, R. B.; Stoddart, J. F. Tunable Solid-State Fluorescent Materials for Supramolecular Encryption. Nature Commun. 2015, 6, 6884.
Bruns, C. J.*; Fujita, D.*; Hoshino, M.; Sato, S.; Stoddart, J. F.; Fujita, M. Emergent Ion-Gated Binding of Cationic Host-Guest Complexes Within Cationic M12L24 Molecular Flasks. J. Am. Chem. Soc. 2014, 136, 12027–12034
Bruns, C. J.; Stoddart, J. F. Rotaxane-Based Molecular Muscles. Acc. Chem. Res. 2014, 47, 2186–2199.
Bruns, C. J.; Frasconi, M.; Iehl, J.; Hartlieb, K. J.; Schneebeli, S. T.; Cheng, C.; Stupp, S. I.; Stoddart, J. F. Redox Switchable Daisy Chain Rotaxanes Driven by Radical-Radical Interactions. J. Am. Chem. Soc. 2014, 136, 4714–4723. Featured in JACS Spotlights
Bruns, C. J.; Li, J.; Frasconi, M.; Schneebeli, S. T.; Iehl, J.; Jacquot de Rouville, H.-P.; Stupp, S. I.; Voth, G. A.; Stoddart, J. F. An Electrochemically and Thermally Switchable Donor-Acceptor [c2]Daisy Chain Rotaxane. Angew. Chem., Int. Ed. 2014, 53, 1953–1958.
Fahrenbach, A. C.; Bruns, C. J.; Li, H.; Trabolsi, A.; Coskun, A.; Stoddart, J. F. Ground-State Kinetics of Bistable Redox-Active Donor-Acceptor Mechanically Interlocked Molecules. Acc. Chem. Res. 2014, 47, 482–493.
Bruns, C. J.; Stoddart, J. F. Mechanically Interlaced and Interlocked Donor-Acceptor Foldamers. Adv. Polym. Sci. 2013, 261, 271–294.
Bruns, C. J.*; Herman, D. J.*; Minuzzo, J. B.; Lehrman, J. A.; Stupp, S. I. Rationalizing Molecular Design in the Electrodeposition of Anisotropic Lamellar Nanostructures. Chem. Mater. 2013, 25, 4330–4339.
Ruiz-Carretero, A.; Aytun, T.; Bruns, C. J.; Newcomb, C. J.; Tsai, W.-W.; Stupp, S. I. Stepwise Self-Assembly to Improve Solar Cell Morphology. J. Mat. Chem. A 2013, 1, 11674–11681.
Guerrero, A.; Loser, S. C.; Garcia-Belmonte, G.; Bruns, C. J.; Smith, J.; Miyauchi, H.; Stupp, S. I.; Marks, T. J.; Bisquert, J. Solution-Processed Small Molecule: Fullerene Bulk-Heterojunction Solar Cells: Impedance Spectroscopy Deduced Bulk and Interfacial Limits to Fill-Factor. Phys. Chem. Chem. Phys. 2013, 15, 16456–16462.
Juriček, M.*; Barnes, J. C.*; Dale, E. J.; Liu, W.-G.; Strutt, N. L.; Bruns, C. J.; Vermeulen, N. A.; Ghooray, K.; Sarjeant, A. A.; Stern, C. L.; Botros, Y. Y.; Goddard, W. A. III; Stoddart, J. F. Ex2Box: Interdependent Modes of Binding in a Two-Nanometer-Long Synthetic Receptor. J. Am. Chem. Soc. 2013, 135, 12736–12746.
Bruns, C. J.; Stoddart, J. F. Molecular Machines Muscle Up. Nature Nanotechnol. 2013, 8, 9–10.
Zhu, Z.; Bruns, C. J.; Li, H.; Lei, J.; Ke, C.; Liu, Z.; Shafaie, S.; Colquhoun, H. M.; Stoddart, J. F. Synthesis and Solution-State Dynamics of Donor-Acceptor Oligorotaxane Foldamers. Chem. Sci. 2013, 4, 1470–1483.
Barnes, J. C.*; Juriček, M.*; Strutt, N. L.; Frasconi, M.; Sampath, S.; Giesener, M. A.; McGrier, P. L.; Bruns, C. J.; Stern, C. L.; Sarjeant, A. A.; Stoddart, J. F. ExBox: A Polycyclic Aromatic Hydrocarbon Scavenger. J. Am. Chem. Soc. 2013, 135, 183–192.
Bruns, C. J.; Stoddart, J. F. The Mechanical Bond: A Work of Art. Top. Curr. Chem. 2012, 323, 19–72.
Gothard, C. M.*; Bruns, C. J.*; Gothard, N. A.; Grzybowski, B. A.; Stoddart, J. F. Modular Synthesis of Bipyridinium Oligomers and Corresponding Donor-Acceptor Oligorotaxanes with Crown Ethers. Org. Lett. 2012, 14, 5066–5069.
Jacquot de Rouville, H.-P.; Iehl, J.; Bruns, C. J.; McGrier, P. L.; Frasconi, M.; Sarjeant, A. A.; Stoddart, J. F. A Neutral Naphthalene Diimide Rotaxane. Org. Lett. 2012, 14, 5188–5191.
Basuray, A. N.; Jacquot de Rouville, H.-P.; Hartlieb, K. J.; Kikuchi, T.; Strutt, N. L.; Bruns, C. J.; Ambrogio, M. W.; Avestro, A.-J.; Schneebeli, S. T.; Fahrenbach, A. C.; Stoddart, J. F. The Chameleonic Nature of Diazopyrenium Recognition Processes. Angew. Chem., Int. Ed. 2012, 51, 11872–11879.
Fahrenbach, A. C.; Hartlieb, K. J.; Sue, C.-H.; Bruns, C. J.; Barin, G.; Basu, S.; Olson, M. A.; Botros, Y. Y.; Bagabas, A.; Khdary, N.; Stoddart, J. F. Rapid Thermally Assisted Donor-Acceptor Catenation. Chem. Commun. 2012, 48, 9141–9143.
Fahrenbach, A. C.; Bruns, C. J.; Cao, D.; Stoddart, J. F. Ground-State Thermodynamics of Redox-Active Donor-Acceptor Mechanically Interlocked Molecules. Acc. Chem. Res. 2012, 45, 1581–1592.
Loser, S.; Bruns, C. J.; Miyauchi, H.; Ponce Ortiz, R.; Facchetti, A.; Stupp, S. I.; Marks, T. J. A Naphthodithiophene-Diketopyrrolopyrrole Donor Molecule for Efficient Solution-Processed Solar Cells. J. Am. Chem. Soc. 2011, 133, 8142–8145.
Bruns, C. J.; Basu, S.; Stoddart, J. F. Improved Synthesis of 1,5-DinaphthoCrown-10. Tetrahedron Lett. 2010, 51, 983–986.
Forgan, R. S.; Friedman, D. C.; Stern, C. L.; Bruns, C. J. Stoddart, J. F. Directed Self-Assembly of a Ring-in-Ring Complex. Chem. Commun. 2010, 5861–5863. Front Cover
Boonya-Udtayan, S.; Yotapan, N.; Woo, C.; Bruns, C. J.; Ruchirawat, S.; Thasana, N. Synthesis and Biological Activities of Azalamellarins. Chem. Asian J. 2010, 5, 2113–2123.
"This book will serve very well to inform any chemist or chemistry student curious as to the workings of molecular topology and the molecular machines that depend upon it, and should be read by anyone seeking to enter these fields. The writing is elegant and at times playful-thoroughly enjoyable to read. This book will certainly occupy pride of place in my research group' library." Jonathan Nitschke
“… a spectacular book! Many chemists will want to have it on their desks and regard it as the holy writ.” Josef Michl
“The story is told by THE inventor-pioneer-master in the field and is accompanied by amazing illustrations… [it] will become an absolute reference and a best seller in chemistry!” Alberto Credi
“… the great opus on the mechanical bond. A most impressive undertaking!” Jean-Marie Lehn
“I love the first chapter, and its romp through the mechanical bond.” Roald Hoffman
“… what a wonderful read… I thoroughly enjoyed the scientifically atypical perspective. A real pleasure.” Bruce Gibb
“… comprehensive coverage [and] exceptional top-quality graphics… this [is a] definitive book.” Paul Beer
"The Nature of the Mechanical Bond will open new horizons for generations of readers and will stimulate the creativity of many architects of matter who wish to design more and more fascinating molecular systems." Claude Millot
In molecules, the mechanical bond is not shared between atoms—it is a bond that arises when molecular entities become entangled in space. Just as supermolecules are held together by supramolecular interactions, mechanomolecules, such as catenanes and rotaxanes, are maintained by mechanical bonds. This emergent bond endows mechanomolecules with a whole suite of novel properties relating to both form and function. They hold unlimited promise for countless applications, ranging from their presence in molecular devices and electronics to their involvement in remarkably advanced functional materials. The Nature of the Mechanical Bond is a comprehensive review of much of the contemporary literature on the mechanical bond, accessible to newcomers and veterans alike. Topics covered include:
– Supramolecular, covalent, and statistical approaches to the formation of entanglements that underpin mechanical bonds in molecules and macromolecules
– Kinetically and thermodynamically controlled strategies for synthesizing mechanomolecules
– Chemical topology, molecular architectures, polymers, crystals, and materials with mechanical bonds
– The stereochemistry of the mechanical bond (mechanostereochemistry), including the novel types of dynamic and static isomerism and chirality that emerge in mechanomolecules
– Artificial molecular switches and machines based on the large-amplitude translational and rotational motions expressed by suitably designed catenanes and rotaxanes.
This contemporary and highly interdisciplinary field is summarized in a visually appealing, image-driven format, with more than 800 illustrations covering both fundamental and applied research. The Nature of the Mechanical Bond is a must-read for everyone, from students to experienced researchers, with an interest in chemistry’s latest and most non-canonical bond.