THE CAO LAB

Organic materials research at a primarily undergraduate institution
NEWS

Ferroelectric Paper

Another piece of the saga of lock-arm supramolecular ordering-based organic ferroelectric crystals from Dennis’ ongoing graduate and postdoctoral project has been published in JACS. This time, the observation of two dimensions of polarization is presented alongside strong evidence for non-centrosymmetry.

Summer students

Once again this summer we have a busy group. This year we welcome four fresh faces as part of an HHMI-funded Young Researchers program. Stella, Fernando, Nhu, and Hiywot will be with us for 10 weeks, studying organic chemistry and synthesizing aromatic compounds. Welcome!

Honors for Penny

Penny successfully defended her thesis today! Her interdisciplinary Honors project relied on her chemistry skills to determine the content of secretions made by harvestmen, better known as daddy long-legs. Penny’s findings have provided significant insight into the evolution of mating behavior. Congrats Penny!

Welcome Kellie

Kellie Stellmach is a first-year who is joining the lab. She will be investigating the co-crystallization of complementary hydrogen-bonding partners, welcome Kellie!

Been away for a while? Old News can be found here.

RESEARCH

REDOX-ACTIVE SMALL MOLECULES

We are intrigued by small molecules with optical and electronic properties that are attractive in electronic materials applications. Specifically, our efforts revolve around the design, synthesis, and characterization of aromatic imides.

SELF-ASSEMBLED STRUCTURES

We are interested in new synthetic strategies for bringing small molecules together to build higher order structures. Currently, we are tackling the formation of both discrete single molecular oligomers and developing new motifs for the formation of extended supramolecular networks.

PEOPLE

Nhu Nguyen '20

Nhu is from Portland, Oregon. She plans to major in biology with a concentration in community and global health, along with a minor in chemistry. Although this is her first research experience, she is excited to expand her knowledge in chemistry and hopes to gain valuable skills from working in the Cao lab. After Macalester, she is pursuing a career in the health field, specifically into nursing or a physician assistant. Outside of research, Nhu enjoys traveling, hiking, photography, and learning about different cultures.

Mohammed Modan '18

Aromatic Imides

Mohammed is from Marin County, California. He is a Chemistry major with an emphasis in Biochemistry. Although this is his first research experience, he is excited to apply what he has learned from years of chemistry in the classroom to make discoveries in the lab. He began this research with a focus on computational chemistry, marrying the subject with his love of technology. As for the future, Mohammed is considering a career in healthcare, either as a physician, or in a related science such as medicinal chemistry. Outside of chemistry and technology, Mohammed enjoys hiking/camping, trail running, slacklining, and posting pictures of Joe.

Qifan Xiao '18

Aromatic Imides

Qifan is from Chengdu, China. He is a sophomore Chemistry major. Qifan’s passion for chemistry started with the copper sulfate solution he found in his “Little Chemist's Kit” birthday gift. He got a glimpse of real chemistry world in the summer of 2015 when he worked in Professor Xia’s group in Nuclear Chemistry Laboratory at Sichuan University, focusing on the grafting of graphite oxide to synthesize porous materials. He is excited to join the Cao Lab and to work on novel compounds, and is looking forward to become a chemical engineer in the future. Besides chemistry, Qifan likes chess, classical guitar, travelling and exploring restaurants.

Eman Ahmed '17

Self-Assembled Structures

Eman is from Karachi, Pakistan. She is a rising junior, Chemistry major and Biology minor. She developed her interest for research after working in Dr. Marcos Ortega’s lab last summer, where she purified protein gpA, which is involved in the insertion of the viral DNA into a procapsid. After taking organic chemistry at Macalester, she developed an interest in the synthesis of molecules, since it allows her to challenge herself. She is excited to be a part of the Cao lab where she will be working on assembling organic cages. Outside of Chemistry, Eman enjoys eating desserts, travelling, exercising and shopping.

Stella Matutina Ikuzwe ‘20

Aromatic Imides

Stella is from Kigali, Rwanda. She is a rising sophomore majoring in Chemistry and considering doing Biochemistry emphasis and Statistics minor. Her interest in Chemistry grew when she conducted an independent research in which she analyzed factors that affect the alcohol content produced during the fermentation of banana juice; as part of her International Baccalaureate program requirement. Stella is so excited to work in Professor Cao’s lab and hopes to further enhance her interest in Chemistry. As for the future, Stella is hoping to pursue a career in medicinal chemistry and related fields. Outside of school, Stella likes to read, watch movies, sing, dance and volunteer.

Kellie Stellmach '20

Self-Assembled Structures

Kellie is from Salem, Oregon. She plans to major in chemistry, and is considering minoring in mathematics. As a student in the International Baccalaureate program, she conducted an independent research project to analyze the impact of fertilization practices at a local vineyard on the chemical quality of the groundwater. She is eager to further explore her interests in organic chemistry and material sciences in the Cao Lab. After Macalester, she hopes to attend graduate school and possibly pursue a career in research and development. She loves to sing, play piano, and spend time with animals, including her cats, goats, and chicken back at home.

Joseph Romo '18

Self-Assembled Structures

Joe is from Long Island, New York. He is a sophomore Chemistry major with Added Emphasis in Biochemistry. Joe’s interest in research started early on during his high school career. Under the guidance of Dr. Michael Vaccariello, Joe investigated the effects of artificial sweeteners on Drosophila melanogaster. His work led him to receive the notable Principal’s Award of Excellence in Scientific Research for four consecutive years. Outside of the lab, Joe enjoys fishing, traveling, photography, and watching New York Yankees baseball.

Hiywot Tulu

Hiywot Tulu is originally from Addis Abeba, Ethiopia but she immigrated to Nashville, TN. She is a rising sophomore who’s interested in majoring in neuroscience and minoring in chemistry and arbaic. Hiywot enjoy chemistry and is hoping to use her first research experience in the Cao lab to help decide whether she wants to pursue a major in chemistry. In the future, she plans on pursuing a career in the medical/health field. Hiywot is a Bonner Community Scholar and she’s excited to work at Peter J. King Family Health Clinic this upcoming fall. Outside of school, Hiywot enjoys attending church, swimming, hiking, running, traveling, and reading.

Dennis Cao

Dennis was born in Konstanz, Germany and grew up in San Diego, California. He began his education at UC Berkeley in 2006 and did his undergrad research with Dr. Yi Liu at Lawrence Berkeley National Laboratory. In 2010, Dennis found his way into grad school and Prof. J. Fraser Stoddart's lab at Northwestern where he crystallized metal-organic frameworks and organic ferroelectrics before graduating in June 2014. He then did a postdoctoral stint in Prof. Samuel I. Stupp’s group, working on self-assembling materials. Dennis' independent career at Macalester College began in August 2015, where he is teaching organic chemistry and mentoring research students. Outside of chemistry, Dennis tries to balance his lifestyle with passions for photography, travel, Houston Rockets basketball, and a various random hobbies.

PUBLICATIONS

2017

Tayi, Alok S; Shveyd, Alexander K; Sue, Andrew C -H; Szarko, Jodi M; Rolczynski, Brian S; Cao, Dennis ; Kennedy, Jackson T; Sarjeant, Amy A; Stern, Charlotte L; Paxton, Walter F; Wu, Wei ; Dey, Sanjeev K; Fahrenbach, Albert C; Guest, Jeffrey R; Mohseni, Hooman ; Chen, Lin X; Wang, Kang L; Stoddart, Fraser J; Stupp, Samuel I

Tayi et al. reply to G. D’Avino et al. (regarding Nature 488, 485–489 (2012)) Journal Article

Nature, 547 (7662), pp. E14–E15, 2017, ISSN: 0028-0836.

Links | BibTeX

Narayanan, Ashwin ; Cao, Dennis ; Frazer, Laszlo ; Tayi, Alok S; Blackburn, Anthea K; Sue, Andrew C -H; Ketterson, John B; Stoddart, Fraser J; Stupp, Samuel I

Ferroelectric Polarization and Second Harmonic Generation in Supramolecular Cocrystals with Two Axes of Charge-Transfer Journal Article

Journal of the American Chemical Society, 139 (27), pp. 9186–9191, 2017, ISSN: 0002-7863.

Abstract | Links | BibTeX

2015

Sun, Junling ; Wu, Yilei ; Liu, Zhichang ; Cao, Dennis ; Wang, Yuping ; Cheng, Chuyang ; Chen, Dongyang ; Wasielewski, Michael R; Stoddart, Fraser J

Visible Light-Driven Artificial Molecular Switch Actuated by Radical–Radical and Donor–Acceptor Interactions Journal Article

J. Phys. Chem. A, 119 (24), pp. 6317–6325, 2015, ISSN: 1089-5639.

Abstract | Links | BibTeX

Sue, Andrew C -H; Mannige, Ranjan V; Deng, Hexiang ; Cao, Dennis ; Wang, Cheng ; Gándara, Felipe ; Stoddart, Fraser J; Whitelam, Stephen ; Yaghi, Omar M

Heterogeneity of Functional Groups in a Metal–organic Framework Displays Magic Number Ratios Journal Article

Proc. Nat. Acad. Sci., 112 (18), pp. 5591–5596, 2015, ISSN: 0027-8424, 1091-6490.

Abstract | Links | BibTeX

2014

Liu, Zhichang ; Liu, Guoliang ; Wu, Yilei ; Cao, Dennis ; Sun, Junling ; Schneebeli, Severin T; Nassar, Majed S; Mirkin, Chad A; Stoddart, Fraser J

Assembly of Supramolecular Nanotubes from Molecular Triangles and 1,2-Dihalohydrocarbons Journal Article

J. Am. Chem. Soc., 136 (47), pp. 16651−16660, 2014, ISSN: 0002-7863.

Abstract | Links | BibTeX

Blackburn, Anthea K; Sue, Andrew C -H; Shveyd, Alexander K; Cao, Dennis ; Tayi, Alok ; Narayanan, Ashwin ; Rolczynski, Brian S; Szarko, Jodi M; Bozdemir, Ozgur A; Wakabayashi, Rie ; Lehrman, Jessica A; Kahr, Bart ; Chen, Lin X; Nassar, Majed S; Stupp, Samuel I; Stoddart, Fraser J

Lock-Arm Supramolecular Ordering: A Molecular Construction Set for Cocrystallizing Organic Charge Transfer Complexes Journal Article

J. Am. Chem. Soc., 136 , pp. 17224−17235, 2014, ISSN: 0002-7863.

Abstract | Links | BibTeX

Frasconi, Marco ; Kikuchi, Takashi ; Cao, Dennis ; Wu, Yilei ; Liu, Wei-Guang ; Dyar, Scott M; Barin, Gokhan ; Sarjeant, Amy A; Stern, Charlotte L; Carmieli, Raanan ; Wang, Cheng ; Wasielewski, Michael R; Goddard, William A; Stoddart, Fraser J

Mechanical Bonds and Topological Effects in Radical Dimer Stabilization Journal Article

J. Am. Chem. Soc., (136), pp. 11011−11026, 2014, ISSN: 0002-7863.

Abstract | Links | BibTeX

Cao, Dennis ; Hong, Michael ; Blackburn, Anthea K; Liu, Zhichang ; Holcroft, James M; Stoddart, Fraser J

Two-point Halogen Bonding between 3,6-Dihalopyromellitic Diimides Journal Article

Chem. Sci., (5), pp. 4242−4248, 2014, ISSN: 2041-6539.

Abstract | Links | BibTeX

Liu, Zhichang ; Lei, Juying ; Frasconi, Marco ; Li, Xiaohu ; Cao, Dennis ; Zhu, Zhixue ; Schneebeli, Severin T; Schatz, George C; Stoddart, Fraser J

A Square-Planar Tetracoordinate Oxygen-Containing Ti4O17 Cluster Stabilized by Two 1,1′-Ferrocenedicarboxylato Ligands Journal Article

Angew. Chem. Int. Ed., pp. 9193−9197, 2014, ISSN: 1521-3773.

Abstract | Links | BibTeX

2013

Hartlieb, Karel J; Blackburn, Anthea K; Schneebeli, Severin T; Forgan, Ross S; Sarjeant, Amy A; Stern, Charlotte L; Cao, Dennis ; Stoddart, Fraser J

Topological Isomerism in a Chiral Handcuff Catenane Journal Article

Chem. Sci., 5 (1), pp. 90−100, 2013, ISSN: 2041-6539.

Abstract | Links | BibTeX

Cao, Dennis ; Juríček, Michal ; Brown, Zachary J; Sue, Andrew C -H; Liu, Zhichang ; Lei, Juying ; Blackburn, Anthea K; Grunder, Sergio ; Sarjeant, Amy A; Coskun, Ali ; Wang, Cheng ; Farha, Omar K; Hupp, Joseph T; Stoddart, Fraser J

Three-Dimensional Architectures Incorporating Stereoregular Donor–Acceptor Stacks Journal Article

Chem. Eur. J., 19 (26), pp. 8457−8465, 2013, ISSN: 1521-3765.

Abstract | Links | BibTeX

Liu, Zhichang ; Frasconi, Marco ; Lei, Juying ; Brown, Zachary J; Zhu, Zhixue ; Cao, Dennis ; Iehl, Julien ; Liu, Guoliang ; Fahrenbach, Albert C; Botros, Youssry Y; Farha, Omar K; Hupp, Joseph T; Mirkin, Chad A; Fraser Stoddart, J

Selective Isolation of Gold Facilitated by Second-Sphere Coordination with α-Cyclodextrin Journal Article

Nature Commun., 4 , pp. 1855, 2013, ISSN: 2041-1733.

Abstract | Links | BibTeX

Barnes, Jonathan C; Fahrenbach, Albert C; Cao, Dennis ; Dyar, Scott M; Frasconi, Marco ; Giesener, Marc A; Benítez, Diego ; Tkatchouk, Ekaterina ; Chernyashevskyy, Oleksandr ; Shin, Weon Ho ; Li, Hao ; Sampath, Srinivasan ; Stern, Charlotte L; Sarjeant, Amy A; Hartlieb, Karel J; Liu, Zhichang ; Carmieli, Raanan ; Botros, Youssry Y; Choi, Jang Wook ; Slawin, Alexandra M Z; Ketterson, John B; Wasielewski, Michael R; Goddard, William A; Stoddart, Fraser J

A Radically Configurable Six-State Compound Journal Article

Science, 339 (6118), pp. 429−433, 2013, ISSN: 0036-8075, 1095-9203.

Abstract | Links | BibTeX

Jia, Chuancheng ; Li, Hao ; Jiang, Jiaolong ; Wang, Jindong ; Chen, Hongliang ; Cao, Dennis ; Stoddart, Fraser J; Guo, Xuefeng

Interface-Engineered Bistable [2]Rotaxane-Graphene Hybrids with Logic Capabilities Journal Article

Adv. Mater., 25 (46), pp. 6752−6759, 2013, ISSN: 1521-4095.

Links | BibTeX

2012

Xue, Min ; Cao, Dennis ; Stoddart, Fraser J; Zink, Jeffrey I

Size-Selective pH-Operated Megagates on Mesoporous Silica Materials Journal Article

Nanoscale, 4 (23), pp. 7569−7574, 2012, ISSN: 2040-3372.

Abstract | Links | BibTeX

Tayi, Alok S; Shveyd, Alexander K; Sue, Andrew C -H; Szarko, Jodi M; Rolczynski, Brian S; Cao, Dennis ; Kennedy, Jackson T; Sarjeant, Amy A; Stern, Charlotte L; Paxton, Walter F; Wu, Wei ; Dey, Sanjeev K; Fahrenbach, Albert C; Guest, Jeffrey R; Mohseni, Hooman ; Chen, Lin X; Wang, Kang L; Stoddart, Fraser J; Stupp, Samuel I

Room-Temperature Ferroelectricity in Supramolecular Networks of Charge-Transfer Complexes Journal Article

Nature, 488 (7412), pp. 485−489, 2012, ISSN: 0028-0836.

Abstract | Links | BibTeX

Wang, Cheng ; Dyar, Scott M; Cao, Dennis ; Fahrenbach, Albert C; Horwitz, Noah ; Colvin, Michael T; Carmieli, Raanan ; Stern, Charlotte L; Dey, Sanjeev K; Wasielewski, Michael R; Stoddart, Fraser J

Tetrathiafulvalene Hetero Radical Cation Dimerization in a Redox-Active [2]Catenane Journal Article

J. Am. Chem. Soc., 134 (46), pp. 19136−19145, 2012, ISSN: 0002-7863.

Abstract | Links | BibTeX

Cao, Dennis ; Wang, Cheng ; Giesener, Marc A; Liu, Zhichang ; Stoddart, Fraser J

A Rigid Donor–Acceptor Daisy Chain Dimer Journal Article

Chem. Commun., 48 (54), pp. 6791−6793, 2012, ISSN: 1364-548X.

Abstract | Links | BibTeX

Fahrenbach, Albert C; Bruns, Carson J; Cao, Dennis ; Stoddart, Fraser J

Ground-State Thermodynamics of Bistable Redox-Active Donor–Acceptor Mechanically Interlocked Molecules Journal Article

Acc. Chem. Res., 45 (9), pp. 1581−1592, 2012, ISSN: 0001-4842.

Abstract | Links | BibTeX

Wang, Cheng ; Li, Zongxi ; Cao, Dennis ; Zhao, Yan-Li ; Gaines, Justin W; Bozdemir, Altan O; Ambrogio, Michael W; Frasconi, Marco ; Botros, Youssry Y; Zink, Jeffrey I; Stoddart, Fraser J

Stimulated Release of Size-Selected Cargos in Succession from Mesoporous Silica Nanoparticles Journal Article

Angew. Chem. Int. Ed., 51 (22), pp. 5460−5465, 2012, ISSN: 1521-3773.

Links | BibTeX

Wang, Cheng ; Cao, Dennis ; Fahrenbach, Albert C; Grunder, Sergio ; Dey, Sanjeev K; Sarjeant, Amy A; Stoddart, Fraser J

The Effects of Conformation on the Noncovalent Bonding Interactions in a Bistable Donor–Acceptor [3]Catenane Journal Article

Chem. Commun., 48 (74), pp. 9245−9247, 2012, ISSN: 1364-548X.

Abstract | Links | BibTeX

Wang, Cheng ; Cao, Dennis ; Fahrenbach, Albert C; Fang, Lei ; Olson, Mark A; Friedman, Douglas C; Basu, Subhadeep ; Dey, Sanjeev K; Botros, Youssry Y; Stoddart, Fraser J

Solvent-Dependent Ground-State Distributions in a Donor–Acceptor Redox-Active Bistable [2]Catenane Journal Article

J. Phys. Org. Chem., 25 (7), pp. 544−552, 2012, ISSN: 1099-1395.

Abstract | Links | BibTeX

Fahrenbach, Albert C; Zhu, Zhixue ; Cao, Dennis ; Liu, Wei-Guang ; Li, Hao ; Dey, Sanjeev K; Basu, Subhadeep ; Trabolsi, Ali ; Botros, Youssry Y; Goddard, William A; Stoddart, Fraser J

Radically Enhanced Molecular Switches Journal Article

J. Am. Chem. Soc., 134 (39), pp. 16275−16288, 2012, ISSN: 0002-7863.

Abstract | Links | BibTeX

Forgan, Ross S; Wang, Cheng ; Friedman, Douglas C; Spruell, Jason M; Stern, Charlotte L; Sarjeant, Amy A; Cao, Dennis ; Stoddart, Fraser J

Donor–Acceptor Ring-in-Ring Complexes Journal Article

Chem. Eur. J., 18 (1), pp. 202−212, 2012, ISSN: 1521-3765.

Abstract | Links | BibTeX

2011

Hanifi, David ; Cao, Dennis ; Klivansky, Liana M; Liu, Yi

Novel C3-Symmetric n-Type Tris(aroyleneimidazole) and its Analogs: Synthesis, Physical Properties and Self-Assembly Journal Article

Chem. Commun., 47 (12), pp. 3454−3456, 2011, ISSN: 1364-548X.

Abstract | Links | BibTeX

2010

Koshkakaryan, Gayane ; Jiang, Peng ; Altoe, Virginia ; Cao, Dennis ; Klivansky, Liana M; Zhang, Yue ; Chung, Sungwook ; Katan, Allard ; Martin, Florent ; Salmeron, Miquel ; Ma, Biwu ; Aloni, Shaul ; Liu, Yi

Multilayered Nanofibers from Stacks of Single-Molecular Thick Nanosheets of Hexakis(alkoxy)triphenylenes Journal Article

Chem. Commun., 46 (45), pp. 8579−8581, 2010, ISSN: 1364-548X.

Abstract | Links | BibTeX

Cao, Dennis ; Amelia, Matteo ; Klivansky, Liana M; Koshkakaryan, Gayane ; Khan, Saeed I; Semeraro, Monica ; Silvi, Serena ; Venturi, Margherita ; Credi, Alberto ; Liu, Yi

Probing Donor−Acceptor Interactions and Co-Conformational Changes in Redox Active Desymmetrized [2]Catenanes Journal Article

J. Am. Chem. Soc., 132 (3), pp. 1110−1122, 2010, ISSN: 0002-7863.

Abstract | Links | BibTeX

Koshkakaryan, Gayane ; Cao, Dennis ; Klivansky, Liana M; Teat, Simon J; Tran, Jasper L; Liu, Yi

Dual Selectivity Expressed in [2 + 2 + 1] Dynamic Clipping of Unsymmetrical [2]Catenanes Journal Article

Org. Lett., 12 (7), pp. 1528−1531, 2010, ISSN: 1523-7060.

Abstract | Links | BibTeX

2009

Koshkakaryan, Gayane ; Klivansky, Liana M; Cao, Dennis ; Snauko, Marian ; Teat, Simon J; Struppe, Jochem O; Liu, Yi

Alternative Donor−Acceptor Stacks from Crown Ethers and Naphthalene Diimide Derivatives: Rapid, Selective Formation from Solution and Solid State Grinding Journal Article

J. Am. Chem. Soc., 131 (6), pp. 2078−2079, 2009, ISSN: 0002-7863.

Abstract | Links | BibTeX

Klivansky, Liana M; Koshkakaryan, Gayane ; Cao, Dennis ; Liu, Yi

Linear π-Acceptor-Templated Dynamic Clipping to Macrobicycles and [2]Rotaxanes Journal Article

Angew. Chem. Int. Ed., 48 (23), pp. 4185−4189, 2009, ISSN: 1521-3773.

Abstract | Links | BibTeX