Seminars Archive

Dr. Lissa Anderson | Florida State University

Professor Don Hunt

Marie Payne Graham Lecture| On the Nature of the Entropic Bond | 7:00 pm | Gilmer 390

Dr. Sharon Glotzer | University of Michigan |

Professor Kateri DuBay

On the Nature of the Entropic Bond

Entropy is typically associated with disorder; yet, the counterintuitive notion that particles with no interactions other than excluded volume might self-assemble from a fluid phase into an ordered crystal has been known since the mid-20th century. First predicted for rods, and then spheres, the thermodynamic ordering of hard shapes by nothing more than crowding is now well established. In recent years, surprising discoveries of entropically ordered colloidal crystals of extraordinary structural complexity have been predicted by computer simulation and observed in the laboratory. Colloidal quasicrystals, clathrate structures, and structures with large and complex unit cells typically associated with metal alloys, or obtained in systems of interacting nanoparticles, can all self-assemble from disordered phases of identical particles due solely to entropy maximization. In this talk, we show how entropy alone can produce order and complexity beyond that previously imagined, both in colloidal crystal structure as well as in the kinetic pathways connecting fluid and crystal phases. We show how entropic forces can be directional and introduce the concept of the entropic bond. We introduce a new theory of entropic bonding and show how methods used by the quantum community to predict atomic crystal structures can be used to predict entropic colloidal crystals.

POSTPONED - Dr. Mitch Smith | Michigan State University

Professor Charlie Machan

Hecht Lecture

Dr. Neal Deveraj | University of California, San Diego | Professor of Chemistry and Biochemistry, Murray Goodman Endowed Chair in Chemistry and Biochemistry

Sidney Hecht, Ph.D.

Stereoselective Synthesis and Applications of Sulfonylcyclopropanols as Modular Cyclopropanone and Homoenolate Equivalents

Dr. Vincent Lindsay | North Carolina State University |

Professor Mike Hilinski

Cyclopropanone derivatives have long been regarded as unusable and elusive synthetic intermediates, mainly owing to their prominent ring strain and kinetic instability. In this work, we report the enantioselective synthesis of sulfonylcyclopropanols, shown to be modular and versatile
synthetic equivalents of the corresponding cyclopropanone derivatives. These reagents were found to smoothly react in a variety of reaction manifolds, including organometallic 1,2-addition affording cyclopropanols, nitrene chemistry to access chiral β-lactams, nickel-catalyzed C–C
activation to cyclopentenones, as well as olefination chemistry as a general platform to chiral alkylidenecyclopropanes and other substituted cyclopropanes. Moreover, we have shown that these sulfonylcyclopropanols can also behave as ‘electrophilic homoenolate’ equivalents,
effectively acting as ring-opened 2- or 3-carbon linchpin reagents depending on the reaction conditions. This work constitutes the first general enantioselective route to cyclopropanone equivalents, thus unlocking a number of novel synthetic disconnections relevant to a variety of
chemical industries.

Dr. Leah Dodson | University of Maryland, College Park

Professor Eric Herbst

Dr. Christina Cooley | Trinity University

Professor Mike Hilinski

Dr. Robert Gilliard | University of Virginia

Professor Jill Venton

Dr. Javier Grajeda | Eastman

Professor Brent Gunnoe

Dr. Ryan Fortenberry | University of Mississippi

Professor Robin Garrod

Dr. Charles Machan | University of Virginia

Professor Dean Harman

Special Seminar

Tuning the Reactivity Landscape of Metalloenzymes: From Active Site Modifications to Long-range Dynamic Effects | Dr. Paulo Zaragoza |University of California, Berkeley

UVA Rising Star in Chemistry Postdoctoral Seminar series

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