Larry G. Sneddon

Photo: 
First Name: 
Larry G.
Last Name: 
Sneddon
Official Title: 
Emeritus Professor of Chemistry

Inorganic, Energy and Materials Chemistry

Contact Information
Office Location: 
452 Chem ’73
Email: 
lsneddon@sas.upenn.edu
Phone: 
(215) 898-8632
Admin Support: 
Education: 
  • B.S. Centenary College of Louisiana (1967)
  • Ph.D. Indiana University (1971)
  • Postdoctoral Fellow, University of Virginia (1971-73)
  • Postdoctoral Fellow, Massachusetts Institute of Technology (1973-74)
Research Interests: 

 

Our research in inorganic chemistry, energy-storage and materials science includes synthetic studies in main-group, transition metal and materials chemistry along with physical and structural investigations of molecular, polymeric, and solid-state materials. Brief overviews of ongoing projects are presented in the following sections.

 

Alternative Energy Carriers: New Chemical Methods for Hydrogen Storage

 

The development of efficient methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. We are exploring the use of chemical hydrides such as ammonia borane and ammonia triborane to store and deliver large amounts of hydrogen through dehydrogenation and/or hydrolysis reactions. As depicted in the example in Figure 1, we have shown that the rate and the extent of hydrogen release from these amineboranes can be significantly increased through the use of metal catalysts, ionic liquids and/or chemical additives. We are continuing to investigate both new methods for the controlled hydrogen release from amineboranes and the development of energy-efficient methods for their regeneration from spent-fuel products.

 

Figure 1. Rhodium catalyzed hydrolysis of ammonia triborane

 

Chemical Precursors to Ultra High Temperature Aerospace Materials

The production of complex structural and electronic materials in useable forms is one of the most challenging problems of modern solid-state chemistry and materials science. Our research in this area is focused on the design, syntheses and applications of new processible molecular and/or polymeric precursors to advanced carbide, nitride and boride ceramics that allow the formation of these technologically important materials in forms that cannot be produced with conventional methods. We are especially interested in ultra high temperature materials, such as HfB2 and ZrB2 based composites, that are potentially important in hypersonic (i.e. flying faster than 5 times the speed of sound) aerospace vehicles (Figure 2). A second part of the project is focused on the formation and properties of micro- and nanostructured ceramics, including fibers, tubes and porous materials.

 

Figure 2. New chemical precursor systems for ultra high temperature hafnium-ceramics that were developed at Penn

 

Transition Metal-Promoted Reactions of Inorganic Compounds

We are developing new general, metal-catalyzed methodologies that enable the systematic, high-yield syntheses of important polyborane compounds and materials. Our goals are both to discover new types of catalytic reactions and to develop an understanding of their fundamental reaction mechanisms and controlling factors.

 

Figure 3. (Left) Metal-catalyzed synthesis of the poly(norbornenyldecaborane) polymer; and (Right) The crystallographically determined structure of a new dendritic decaborane (you can manipulate this molecule online at

 

Ionic Liquid Promoted Reactions

 

Ionic liquids have properties that make them attractive solvents for synthesis, including: negligible vapor pressures, thermal stability to elevated temperatures; the ability to dissolve a range of compounds, salts and gases, immiscibility with many hydrocarbons and/or water thus enabling two-phase reaction systems, weakly-coordinating anions and cations that provide a polar, inert reaction medium, and the ability to stabilize polar intermediates and/or transition states. While ionic liquids have been widely employed for organic synthesis, our recent work showing that decaborane olefin-hydroboration and alkyne-insertion reactions proceed in biphasic ionic-liquid/hydrocarbon solvents without the need of the catalysts required in conventional solvents, was the first demonstration of the unique activating effects of ionic liquids for polyborane syntheses. We are continuing to explore the scope of ionic liquid mediated polyborane reactions along with experimental and computational studies of the mechanisms by which these reactions occur.

 

Inorganometallic Chemistry

Because of the unusual ranges of their accessible charges and coordination geometries, polyboranes can function as versatile ligands that can stabilize transition metals in a much wider array of environments than their organic counterparts, such as the cyclopentadienide anion. We are using integrated synthetic, structural (NMR and X-ray crystallography), electrochemical, and computational (DFT/GIAO) investigations to elucidate the nature of polyborane-metal bonding. The unique properties of metallapolyborane complexes are also being exploited to design new metallocene-like complexes with chemical, optical and/or bioactivity properties of importance to solid-state and/or anticancer applications. 

 

 

Figure 4. (Left) Comparisons of the bonding modes of the cyclopentadienyl and tricarbadecaboranyl ligands; (Right) The crystallographically determined structures of new maganatricarbadecaboranyl complexes illustrating a cage-slippage reaction analogous to a cyclopentadienyl ring-slippage process

Amos B. Smith III

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First Name: 
Amos B.
Last Name: 
Smith III
Official Title: 
Rhodes-Thompson Professor of Chemistry

Organic Chemistry

Contact Information
Office Location: 
440N
Email: 
smithab@sas.upenn.edu
Phone: 
(215) 898-4860
Fax: 
(215) 898-5129
Admin Support: 
Education: 
  • B.S.- M.S. Bucknell University (1966)
  • Ph.D. Rockefeller University (1972)
  • Associate, Rockefeller University (1972-73)
Research Interests: 

Smith's research interests encompass three diverse areas: natural product synthesis, bioorganic chemistry and materials science. To date, more than 90 architecturally complex natural products having significant bioregulatory properties have been prepared in his Laboratory. In addition, Smith, in collaboration with Ralph Hirschmann, has achieved the design and synthesis of non-peptide peptidomimetics of neuropeptideic hormone/transmitters and protease enzyme inhibitors and, also with Stephen Benkovic (Penn State), haptens for the production of catalytic antibodies capable of peptide bond formation. At Monell, in collaboration with Peter Jurs (Penn State), he pioneered the use of computerized pattern recognition techniques for the analysis of primate chemical communication. Collaborative programs at the LRSM include the chemistry and physics of novel liquid crystals and the fullerenes. To date Smith research achievements have been reported in more than 500 peer reviewed publications.

Emmanuel Skordalakes

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First Name: 
Emmanuel
Last Name: 
Skordalakes
Official Title: 
Associate Professor, Gene Expression and Regulation Program

Biological Chemistry 

Additional Titles: 
Wistar Institute Associate Professor of Chemistry
Contact Information
Email: 
skorda@wistar.org
Phone: 
(215) 495-6884
Fax: 
(215) 573-9889
Education: 
  • 2001-2006: Postdoctoral Fellow, University of California, Berkeley
  • Ph.D.: Imperial College, University of London (2000)
  • M.Sc.: University College London (University of London) (1992)
  • B.Sc.: Anglia Ruskin University, Cambridge (1991)
Research Interests: 

 

The focus of my research lies with protein nucleic acid assemblies that participate in the replication and maintenance of eukaryotic chromosome ends, called telomeres. Telomeres protect chromosome ends from gradual length erosion, prevent end-to-end fusions and recombination, and promote proper chromosome partitioning during meiosis. Telomere length deregulation and telomerase activation are early and perhaps necessary steps in cancer cell evolution. Furthermore, telomerase and telomere dysfunction are thought to contribute to replicative senescence and programmed cell aging. Despite these fundamental roles in maintaining genome integrity and cell fate, surprisingly little is known about the molecular basis of telomere synthesis by telomerase. We are interested in elucidating the mechanism of telomere replication by telomerase and understand how telomere and telomerase binding proteins regulate telomerase activity and protect chromosome ends. The lab primarily uses structural methods coupled with biophysical and biochemical techniques to study the above systems.

Telomerase Function

Telomere replication is mediated by telomerase, an RNA dependent DNA polymerase structurally similar to retroviral reverse transcriptases and viral RNA polymerases. Biochemical studies on telomerase for more than two decades have provided a wealth of information regarding telomerase function and substrate specificity. Despite this information, the biophysical mechanisms underlying telomerase architecture and function are poorly understood. Our goal is to further elucidate the molecular basis of telomere replication by telomerase using structural and biochemical approaches. The information generated here should provide novel insights into the basic mechanisms of telomere replication and length homeostasis. It will further enrich our understanding of the mechanism of DNA replication by polymerases in general. It will provide a framework to design small molecule inhibitors of telomerase that may be of therapeutic value for cancer and other diseases associated with cellular aging.

Telomerase Regulation

In recent years, a number of factors essential for telomerase regulation and telomere maintenance have been identified. The method by which telomerase and associated regulatory factors physically interact and function with each other to maintain appropriate telomere length is poorly understood. Structural and biochemical characterization of these factors, both in isolation and in complex with one another will facilitate our understanding of how the proper function of these factors impacts telomerase function and cell proliferation.

Eric J. Schelter

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First Name: 
Eric J.
Last Name: 
Schelter
Official Title: 
Associate Professor of Chemistry

Inorganic and Materials Chemistry

Contact Information
Office Location: 
3003 IAST
Email: 
schelter@sas.upenn.edu
Phone: 
(215) 898-8633
Fax: 
(215) 573-6743
Twitter: 
@SchelterGroup
Admin Support: 
Education: 
  • B.S. Michigan Technological University (1999)
  • Ph.D. Texas A&M University, Advisor: Kim R. Dunbar (2004)
  • Glenn T. Seaborg Postdoctoral Fellow, Los Alamos National Laboratory (2004-2005)
  • Director's Postdoctoral Fellow, Los Alamos National Laboratory (2006)
  • Frederick Reines Postdoctoral Fellow in Experimental Sciences, Los Alamos National Laboratory (2006-2009)
Research Interests: 

 

Projects in the Schelter Group involve inert atmosphere/Schlenk line synthesis of inorganic and organometallic complexes. Rigorous characterization of new compounds is achieved through X-ray crystallography, NMR, FTIR, and UV-Visible absorption spectroscopies, electrochemistry and magnetic susceptibility studies. Current projects are focused on the chemistries and electronic structure effects of the lanthanides, uranium and main group elements

Advanced Rare Earths Separations Chemistry

The rare earth elements: La-Lu, Y and Sc are used in critical renewable energy applications including wind turbine generators and hybrid electric vehicle batteries. These modern applications require pure rare earth elements that must be separated from their composite mineral sources. The Peoples Republic of China currently holds ~97% of the international rare earths market comprising nearly all aspects of the (environmentally taxing) supply chain. To develop other sources of rare earths and reduce the environmental impact of their isolation, there is a clear need for new separations chemistry that reduces the cost of industrial-scale rare earths separations. This project seeks to develop a totally new extractant strategy by harnessing the physicochemical distinctiveness of certain high-value rare earths. New designer rare earth extractants will enable selective separations chemistry for these technologically critical elements.

 

Capturing Heavy-Fermion Type Electron Correlations in Molecular Complexes

The intermetallic heavy-fermion materials, comprising intermediate valence f-elements such as cerium, are characterized by exotic emergent phenomena including unconventional superconductivity. Recent results on these materials suggest a common energy scale for the emergence of the superconducting state, dependent on the local magnetic interaction of f-moments with conduction electrons. Local electron correlations are also believed to underpin the high Tc superconductivity of other families of materials. Parallel studies in molecular chemistry have begun to show inorganic and organometallic complexes are capable of exhibiting the same type of mixed-valency and correlations found in the heavy-fermion materials.

This project will generalize the requirements for emergence of Kondo-like phenomena in magnetically-dilute molecular complexes. New materials will be synthesized from fundamental units of electron correlation to three-dimensional molecular phases.

 

 

 

Exploring the Inverse Trans Influence in the Chemistry of Uranium

Antithetical to the trans influence in transition metal chemistry, which results in a weakening of metal-ligand bonds trans to strongly-bound groups, is the inverse trans influence in the chemistry of the actinides. Semi-core p-orbital mixing with valence d- or f-orbitals gives rise to the influence, however, the presence of both orbital types in the actinide valence shell precludes its simple description. The large thermodynamic stability of the ubiquitous linear, trans-dioxo uranyl cation, UO22+ is one important consequence of this influence.

This project will develop new complexes in varying geometries and coordination environments to systematically study the inverse trans influence in the structural chemistry of uranium. These results will have direct relevance to the bio-remediation of actinide contaminated ground waters, for which the thermodynamic driving force of the influence plays an important role.

Jeffery G. Saven

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First Name: 
Jeffery G.
Last Name: 
Saven
Official Title: 
Professor of Chemistry

Biological and Theoretical Physical Chemistry

Contact Information
Office Location: 
266 Cret, Lab 261 Cret
Email: 
saven@sas.upenn.edu
Phone: 
215-573-6062
Fax: 
215-573-2112
Admin Support: 
Education: 
  • BA, New College of Florida
  • PhD, Columbia University & University of Wisconsin
  • NSF Postdoctoral Fellow in Chemistry, University of Illinois, Urbana-Champaign, 1993-1995. Postdoctoral Research Associate, University of Illinois, Urbana-Champaign, 1995-1997
Research Interests: 

Computationally designed protein complex containing a nonbiological cofactor, designed and studied in collaboration with the DeGrado and Therien groups in the Department of Chemistry. On the left is the computationally designed protein scaffold (magenta) and two abiotic porphyrin cofactors (yellow). On the right is a model of the computationally designed sequence and structure.

 

Our research interests involve theoretical chemistry, particularly as it applies to biopolymers, macromolecules, condensed phases, and disordered systems. We are developing computational methods for understanding and designing molecular sytems having many physical and chemical degrees of freedom. Molecular simulation techniques are used both to study molecular systems in detail and to test and illustrate our theories. 

 

A current thrust of the group involves developing computational tools for understanding the properties of protein sequences consistent with a chosen three-dimensional structure. The group works closely with experimental groups at Penn and at other universities; some group members are involved in joint theoretical/experimental projects. Recent projects involve the design of soluble and membrane bound proteins, discerning the origins of conservation in naturally occurring proteins, biomolecular simulation, and the design of nonbiological folding molecules.

Andrew M. Rappe

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First Name: 
Andrew M.
Last Name: 
Rappe
Official Title: 
Blanchard Professor of Chemistry

Physical and Theoretical Chemistry

Additional Titles: 
Professor of Materials Science and Engineering
Co-Director, Pennergy
Contact Information
Office Location: 
264 Cret, Lab: 263, 265, 267, 268 Cret
Email: 
rappe@sas.upenn.edu
Phone: 
(215) 898-8313
Fax: 
(215) 573-2112
Admin Support: 
Education: 
  • B.A. Chemistry and Physics, Summa Cum Laude, Harvard University (1986)
  • ONR Graduate Fellow, Massachusetts Institute of Technology (1986-1989)
  • JSEP Graduate Fellow, Massachusetts Institute of Technology (1990-1992)
  • Ph. D. Physics and Chemistry, Massachusetts Institute of Technology (1992)
  • IBM Postdoctoral Fellow, University of California at Berkeley (1992-1994)
  • Assistant Professor of Chemistry, University of Pennsylvania (1994-2000)
  • Associate Professor of Chemistry, University of Pennsylvania (2000-2006)
  • Professor of Chemistry, University of Pennsylvania (2006-present)
  • NSF CAREER Award (1997-2001)
  • Alfred P. Sloan Foundation Fellow (1998-2000)
  • Dreyfus Teacher-Scholar Award (1999-2004)
Research Interests: 

 

My research group creates and uses new theoretical and computational approaches to study complex systems in materials science, condensed-matter physics, and physical chemistry.

 

We look for new phenomena that occur when different components are brought together. For example, we examine molecules adsorbing on metal surfaces, in order to understand the effect of surface composition and structure on preferred adsorption sites, dissociation pathways, and vibrational dynamics. We also study how the compositions of oxide solid solutions lead to Angstrom-scale chemical structure, nanometer scale structural disorder, and long-range ferroelectric and piezoelectric properties. These studies find real-world applications in catalysis, corrosion, SONAR, fuel cells and other important technologies. Whenever possible, we model systems analytically, in order to extract general principles and simple pictures from complex systems. We recently derived general expressions for the vibrational lifetimes of molecules on surfaces, revealing the dependence of lifetime on molecular coverage and arrangement. Our recent exploration of quantum stress fields has helped to link chemical and mechanical effects in materials.

 

We are constantly developing methods for computing new properties, and for making quantum-mechanical calculations more accurate and more efficient. We tailor computational algorithms to maximize performance on modern computing platforms such as Beowulf clusters. Wherever possible, we also model systems analytically, in order to extract general principles and simple pictures from complex systems. This combination of theoretical and computational tools enables us to identify new phenomena in complex systems, like multicenter bonds between methyl radicals and the rhodium surface. ( See figure below )

Converting the 5d wavefunction of gold to a smoother pseudowavefunction results in a dramatic reduction in the required basis set size for converged calculations.

E. James Petersson

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First Name: 
E. James
Last Name: 
Petersson
Official Title: 
Associate Professor of Chemistry
Contact Information
Office Location: 
350 N
Email: 
ejpetersson@sas.upenn.edu
Phone: 
215-746-2221
Admin Support: 
Education: 

• A.B. Dartmouth College (1998)

• Ph.D. California Institute of Technology (2005)

• NIH Postdoctoral Fellow, Yale University (2005-2008)

• Searle Scholar (2010)

• Sloan Research Fellow (2012)

• NSF CAREER Award (2012)

• Award for Early Excellence in Physical Organic Chemistry      (2013)

Research Interests: 

Protein motion underlies both proper function and disease in biological systems. Many signaling and transport proteins require complex rearrangements for function, and some proteins, such as amyloids, misfold into toxic conformations. Studying these protein motions not only aids our understanding of diverse biological phenomena, it also contributes to an important fundamental problem in biochemistry: understanding how motions propagate from one end of a protein to another. The Petersson laboratory is developing tools to address questions of how dynamic proteins mediate communication and how the cellular environment catalyzes protein misfolding, from detailed in vitro folding studies to modeling protein motion in living cells. These tools include novel chromophores, which we synthesize and incorporate into proteins through unnatural amino acid mutagenesis and synthetic protein ligation.

Selected Publications: 

Inteins as Traceless Purification Tags for Unnatural Amino Acid Proteins

Batjargal, S.; Walters, C. R.; Petersson, E. J.

J. Am. Chem. Soc. 2015, 137, 1734-1737.

 

Specific Modulation of Protein Activity Through a Bioorthogonal Reaction

Warner, J. B.; Muthusamy, A. K.; Petersson, E. J.

ChemBioChem 2014, 24, 2508-2514.

 

Thioamide-Based Fluorescent Protease Sensors

Goldberg, J. M.; Chen, X. S.; Meinhardt, N.; Greenbaum, D. C.; Petersson, E. J. 

J. Am. Chem. Soc. 2014, 136, 2086-2093.

 

Efficient Synthesis and In Vivo Incorporation of Acridonylalanine, a Fluorescent Amino Acid for Lifetime and Förster Resonance Energy Transfer/Luminescence Resonance Energy Transfer Studies 

Speight, L. C.; Muthusamy, A. K.; Goldberg, J. M.; Warner, J. B.; Wissner, R. F.; Willi, T.; Woodman, B.; Mehl, R. A.; Petersson,     E. J. 

J. Am. Chem. Soc. 2013, 135, 18806-18814.

 

Expressed Protein Ligation at Methionine: N-terminal Attachment of Homocysteine, Ligation, and Masking

Tanaka, T.; Wagner, A. M.; Warner, J. B.; Wang, Y. J.; Petersson, E. J. 

Angew. Chem. Int. Ed. 2013, 52, 6210-6213.

 

Labeling Proteins with Fluorophore/Thioamide FRET Pairs by Combining Unnatural Amino Acid Mutagenesis and Native Chemical Ligation

Wissner, R. F.; Batjargal, S.; Fadzen, C. M.; Petersson, E. J. 

J. Am. Chem. Soc. 2013, 135, 6529-6540.

 

Thioamide Quenching of Fluorescent Probes Through Photoinduced Electron Transfer: Mechanistic Studies and Applications

Goldberg, J. M.; Batjargal, S.; Chen, B. S.; Petersson, E. J. 

J. Am. Chem. Soc. 2013, 135, 18651-18658.

Virgil Percec

Photo: 
First Name: 
Virgil
Last Name: 
Percec
Official Title: 
P. Roy Vagelos Professor of Chemistry

Organic, Supramolecular and Macromolecular Chemistry

Contact Information
Office Location: 
4003 IAST, Lab: 4160 IAST
Email: 
percec@sas.upenn.edu
Phone: 
(215) 573-5527
Fax: 
(215) 573-7888
Admin Support: 
Education: 
  • B.S. 1969 Department of Organic and Macromolecular Chemistry, Polytechnic Institute of Jassy, Romania
  • Ph.D. 1976 Institute of Macromolecular Chemistry, Jassy, Romania
  • Postdoctoral July-August 1981 Hermann Staudinger Hause, University of Freiburg, Germany
  • Postdoctoral September 1981 - March 1982 Institute of Polymer Science, University of Akron, U.S.A.
Research Interests: 

Our research group is involved in the elaboration of synthetic methods, strategies and architectural concepts, as well as in the understanding of the fundamental principles that govern the rational design and synthesis of complex molecular, macromolecular, and supramolecular nonbiological systems that exhibit biological functions. Biological systems are employed as models to develop the synthetic architectural motifs and to control their self-assembly and self-organization during the creation of ordered systems. Our research strikes a balance among a diversity of interrelated disciplines, such as organic, bioorganic, macromolecular, and supramolecular synthesis and catalysis, seeking to understand, mimic, and extend Nature's solutions to the design of synthetic functional nanosystems. 

 

Hierarchical folding, supramolecular chirality, nonbiological ionic and electronic channels and nanowires, nanostructured supramolecular membranes, externally regulated drug release mechanisms, enzyme-like catalytic systems, and self-interrupted organic and macromolecular synthesis are examples of new concepts that are under investigation. Central to the capacity of biological molecules to perform critical functions is their ability to form highly organized and stable 3-D structures using a combination of molecular recognition processes. Therefore, the combinatorial libraries of synthetic building blocks required in our strategies consist of combinations of macrocyclic, dendritic, and other primary sequences that are able to fold into well-defined conformations and also contain all the information required to control and self-repair their secondary, tertiary, and quaternary structure at the same level of precision as in biological molecules. To what extent the delicate balance between the structures and functions evolved in Nature during billions of years can be transplanted to synthetic molecules is a fascinating question.

 

Towards these goals, we also develop new synthetic methods for the formation of carbon-carbon and carbon-heteroatom bonds using metal-catalyzed homo- and cross-coupling, radical, and various ionic and ion-radical reactions. Living and non-statistically self-interrupted polymerization methods are elaborated based on these organic reactions. The design of the internal structure of complex single molecules and the elucidation of the reactivity principles induced by the controlled environment confined within a single molecule or supramolecule are actively pursued. This research involves collaborations with structural and computational chemists and biochemists.

Christopher B. Murray

Photo: 
First Name: 
Christopher B.
Last Name: 
Murray
Official Title: 
Richard Perry University Professor of Chemistry and Materials Science and Engineering

Nanoscale and Inorganic Materials Chemistry

Contact Information
Office Location: 
347N (Chem 73) & 322 (LRSM) MSE
Email: 
cbmurray@sas.upenn.edu
Phone: 
(215) 898-0588
Admin Support: 
Education: 
  • 1985-1988 B.Sc. Honors Chemistry, Summa cum Laude, St. Mary's University, Halifax N.S., Canada
  • 1989 Rotary International Fellow, University of Auckland, New Zealand
  • 1990-1995 Ph.D. Physical Chemistry, Massachusetts Institute of Technology, Cambridge, MA
  • 1995- 2000 Member of research staff, IBM Corp., T. J. Watson Research Center. Established a program in the preparation and characterization of nanomaterials and devices.
  • 2000 - 2006 Manager of the Nanoscale materials and devices department leading development of nanomaterials and exploring self-organizing phenomena for applications in IT.
  • 2007- University of Pennsylvania: Richard Perry University Professor of Chemistry and Materials Science and Engineering.
Research Interests: 

Our research focuses on Materials Chemistry with full participation in both the departments of Chemistry in the School of Arts and Sciences (SAS) and in the Department of Materials Science and Engineering in the School of of Engineering and Applied Sciences (SEAS).

 

Many collective phenomena in inorganic materials have natural length scales between 1 and 50 nm. Thus size control nanometer sized crystals or "nanocrystals" allows materials properties to be engineered. Nanocrystals display new mesoscopic phenomena found in neither bulk nor molecular systems. For example, the electronic, optical and magnetic properties semiconductors and magnetic nanocrystals strongly depend on crystallite size. Excited by the potential of these nanocrystal materials our mode of operation has been to develop leading synthetic methods and to push the resulting materials toward technology demonstrations. We try to blend the perspective of academic chemistry and materials science with technological perspective that I developed in over a decade of work in industrial research. We hope this mix of influences will help to align opportunities for applications with broader understanding of nanomaterials. Materials chemistry that embraces and harnesses these principles of self-assembly is at the frontier of materials science and become one of its cornerstones within our generation. Key challenges to the advance of this field will be met by advancing synthetic design, improved analytical tools and perhaps through forethought of environmental health and safety issues. Share in efforts to meet these challenges and thus influence the evolution of both materials science and chemistry. 

Other Affiliations: 

Gary A. Molander

Photo: 
First Name: 
Gary A.
Last Name: 
Molander
Official Title: 
Hirschmann-Makineni Professor of Chemistry and Department Chair
Contact Information
Office Location: 
4001 IAST
Email: 
gmolandr@sas.upenn.edu
Phone: 
(215) 573-8604
Fax: 
(215) 573-7165
Twitter: 
@molandergroup
Admin Support: 
Research Interests: 

 

The central theme of the Molander group's research is the development of new synthetic methods and their application to the synthesis of organic molecules. The group's focus is to expand and improve the Suzuki coupling reaction for organoboron compounds. Robust, air- and water-stable potassium organotrifluoroborates (R-BF3K), are employed to carry out couplings under relatively mild conditions using non-toxic components.

Greener Routes to Standard Reagents

The preparation of aryl- and heteroaryl potassium trifluoroborate and trihydroxyborate salts has been modified to take advantage of atom-economical boron sources, such as bis-boronic acid (BBA) and tetrakis(dimethylamino)diboron, which allow low catalyst loading and relatively mild reaction conditions. Reactive boronic acid species are generated, and subsequent coupling reactions with these substrates allow greener access to biaryl products.

 

 

Improving Transformations with More Robust Reagents

 

Organotrifluoroborates allow installation of functional groups within a molecule in the place of an existing carbon-boron bond. This allows one to prepare or purchase a simple, functionalized organotrifluoroborate and to elaborate the structure, drawing on the reactivity of the boron species. Some of the transformations carried out to date in this way are outlined below, highlighting the ability to install a cyclopropyl, hydroxymethyl, or nitroso functional group using potassium trifluoroborates.

 

 

Novel Reagents and Transformations

Some methods have been developed for the synthesis of novel reagents containing alkyltrifluoroborates, namely potassium aminomethyl-, hydroxymethyl-, and a-alkoxyalkyltrifluoroborates. The synthesis of these structures is outlined below with their applications in cross coupling illustrated.

Department of Chemistry

231 S. 34 Street, Philadelphia, PA 19104-6323

215.898.8317 voice | 215.573.2112 fax | web@chem.upenn.edu

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