General

Biological Chemistry seminar: Sua Myong, Johns Hopkins University

Thu, 2018-10-11 15:00
Location: 
Carolyn Hoff Lynch Room

"Defective RNA interaction leads to aberrant phase separation of ALS-linked mutant FUS"

Inorganic Chemistry Seminar: Dr. David Goldberg, Johns Hopkins University

Tue, 2019-02-26 12:00 - 13:00
Speaker: 
Dr. David Goldberg
Location: 

Carol Lynch Lecture Hall

Chemistry Complex

Host: Tomson

Title & Abstract TBA

inquires rvargas@sas.upenn.edu

Organic Chemistry Seminar: Dr. Andrew McNally, Colorado State University

Mon, 2018-11-12 12:00 - 13:00
Speaker: 

Dr. Andrew McNally

Title: Selective Functionalization of Pyridines, Diazine and Pharmaceuticals via Heterocyclic Phosphonium Salts
Abstract: Selective methods that can functionalize electron-deficient heterocycles are in great demand due to their prevalence in biologically active compounds. Pyridines and diazines, in particular, are widespread components of pharmaceutical compounds yet methods to transform these motifs into valuable derivatives are still greatly sought after. We will present a selection of catalytic and non-catalytic methods using  phosphorus intermediates that enable multiple new bond-constructions on these heterocycles. A particular emphasis will be placed on phosphorus ligand-coupling reactions that represent an alternative means to form C–C and C-Heteroatom bonds.
Location: 

Carol Lynch Lecture Hall

Chemistry Complex

Attached Document: 

Host: Dr. Walsh

inquires rvargas@sas.upenn.edu

Inorganic Chemistry Seminar: Dr. Amy Prieto, Colorado State University

Tue, 2018-10-16 12:00 - 13:00
Speaker: 

Dr. Amy Prieto

Title "Inexpensive, Efficient Approaches for Energy Production and Storage"

 

 We are interested in developing new synthetic methods for nanoscale materials with applications in energy conversion and storage. For this talk, I will focus first on using photovoltaic devices to produce energy, and in particular the synthesis and characterization of Cu2ZnSnS4 nanoparticles. The structure-property relationships for these particles can be significantly modified as the metal and chalcogen stoichiometries are tuned.  Second, I’ll discuss our efforts to develop new architectures for rechargeable Li-ion batteries for storing that energy. We are working to incorporate high surface area structures of a novel anode material into a new battery architecture wherein the current collector is conformally coated with an electrolyte made by electrochemical deposition, then surrounded by the cathode electrode. The significant advantage is that the diffusion length for Li+ between the cathode and anode will be dramatically reduced, which should lead to much faster charging rates. The general theme between both topics is the development of new synthetic methods for useful materials with an eye toward non-toxic, earth abundant chemicals and reasonable manufacturing methods.

 

 

M. C. Schulze, R. K. Schulze, A. L. Prieto "Electrodeposited thin-film CuxSb anodes for Li-ion batteries: Enhancement of cycle life via tuning of film composition and engineering of the film-substrate interface" J. Mater. Chem. A20186, 12708-12717.


 

M. Braun, L. Korala, J.  M. Kephart, and A. L. Prieto, “Synthetic Control of Quinary Nanocrystals of a Photovoltaic Material: The Clear Role of Chalcogen Ratio on Light Absorption and Charge Transport for Cu2ZnSn(S1-xSex)4”, ACS Appl. Energy Mater.2018 1(3), 1053-1059.


 

Location: 

Carol Lynch Lecture Hall

Chemistry Complex

Host: Dr Goldberg

inquires rvargas@sas.upenn.edu

Physical Chemistry Seminar, Dr. Sanat Kumar, Columbia University

Thu, 2018-10-11 13:00 - 14:00
Speaker: 

Dr. Sanat Kumar

"Polymer-Grafted Nanoparticle Membranes with Controllable Free-Volume"

 

-Polymer based membranes play a key role in several industrially important gas separation technologies, e.g., removing CO2 from natural gas, with enormous economic and environmental impact. Baker advocates the development of novel membrane architectures since current, pure polymer membranes only offer limited systematic pathways for improvement. Here, we develop a novel hybrid membrane construct comprised entirely of nanoparticles grafted with polymers. These membranes are shown to have broadly tunable separation performance through variations in graft density and chain length. Computer simulations show that the optimal NP packing forces the grafted polymer layer to distort, yielding regions of measurably lower polymer density. Multiple experimental probes confirm that these materials have the predicted increase in “polymer free volume”, which explains their improved separation performance. These polymer-grafted NP materials thus represent a new template for rationally designing membranes with desirable separation abilities, coupled with improved aging characteristics in the glassy state and enhanced mechanical behavior.
Location: 
Carol Lynch Lecture Hall Chemistry Complex

Host: Dr. Fakhraai

 

inquires rvargas@sas.upenn.edu

 

Physical Chemistry Seminar, Dr. Paul Wennberg, Caltech

Thu, 2019-02-07 13:00 - 14:00
Location: 

Carol Lynch Lecture Hall

Chemistry Complex

Host: Dr. Lester

Title & Abstract TBA

Inquiries rvargas@sas.upenn.edu

Inorganic Chemistry Seminar, Dr. Hemamala Karunadasa, Stanford University

Tue, 2018-09-04 12:00 - 13:00
Speaker: 

Dr. Hemamala Karunadasa

Title

Between the sheets: The molecular chemistry of hybrid perovskites

Abstract

The tools of synthetic chemistry allow us to tune molecules with a level of precision not yet accessible with inorganic solids. We have investigated hybrid perovskites that couple organic small molecules with the optical and electronic diversity of extended inorganic solids. I will share our current understanding of these materials, whose technologically relevant properties are highly amenable to synthetic design.

The 3D lead-iodide perovskites have recently been identified as low-cost absorbers for high-efficiency solar cells. Although the efficiencies of devices with perovskite absorbers have risen at an impressive rate, the materials’ intrinsic instability and toxicity may impede their commercialization. I will discuss methods developed by our group to address these problems. The 2D hybrid perovskites have dramatically different properties from their 3D congeners. We discovered that some 2D perovskites emit broadband white light (similar to sunlight) when excited by UV light. I will discuss how these materials, which do not contain extrinsic dopants or obvious emissive sites, could emit every color of visible light. Although the organic molecules in hybrid perovskites have mostly played a templating role, we have investigated their role in engendering reactivity. I will describe reactions that occur between the inorganic sheets, which allow these nonporous solids to capture small molecules.

Brief Bio

Hema Karunadasa studied solid-state chemistry with Bob Cava at Princeton University and molecular catalysis with Jeff Long and Chris Chang at UC Berkeley and with Harry Gray at the California Institute of Technology. She joined Stanford Chemistry as an assistant professor in 2012. Her group synthesizes hybrid materials that harness the advantages of extended solids and discrete molecules.

Location: 

Carol Lynch Lecture Hall

Chemistry Complex

Attached Document: 

Host: Dr. Murray

inquiries rvargas@sas.upenn.edu

Inorganic Chemsitry Seminar: Dr. Matthew Kieber-Emmons, University of Utah

Tue, 2019-04-23 12:00 - 13:00
Speaker: 
Dr. Matthew Kieber-Emmons
Location: 

Carol Lynch Lecture Hall

Chemsitry Complex

Host: Tomson

Title & Abstract: TBA

inquiries rvargas@sas.upenn.edu

Inorganic Chemistry Seminar; Dr. Xavier Roy, Columbia University

Tue, 2019-04-09 00:00 - 01:00
Speaker: 
Dr. Xavier Roy
Location: 

Carol Lynch Lecture Hall

Chemistry Complex

Host: Dr. Murray

Title & Abstract: TBA

inquiries rvargas@sas.upenn.edu

Organic Chemistry Seminar: Dr. David Nagib, Ohio State University

Mon, 2018-12-10 12:00 - 13:00
Speaker: 

Dr. David Naglib

C-H and C-O functionalization via radical chaperones

 


Our research is focused on harnessing the untapped reactivity of abundant chemical feedstocks to enable late-stage functionalization of medicinally relevant molecules. We have recently developed new approaches for selective C-H and C-O functionalization of alcohols, amines, and carbonyls, using a combination of radical (1e-) and closed shell (2e-) processes that act in concert with one another. These radical chaperone strategies have enabled discovery of new classes of reactivity to streamline the synthesis of complex molecules with biological and industrial significance.

Location: 

Carol Lynch Lectrue Hall

Chemistry Complex

Host: Dr. Walsh

inquiries rvargas@sas.upenn.edu

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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