1:30 p.m.           Welcome

 

Professor Paris Svoronos,   2015 Chair, ACS New York Section, CUNY-Queensborough Community College

1:35 p.m.           Opening of the Distinguished Symposium

Professor Alison G. Hyslop,   2015 Chair-Elect, ACS New York Section, St. John's University

1:45 p.m.           Metal-Organic Frameworks

Professor Omar M. Yaghi,  University of California - Berkeley

Metal-organic frameworks (MOFs) represent an extensive class of porous crystals in which organic 'struts' are linked by metal oxide units to make open networks. The flexibility with which their building units can be varied and their ultra-high porosity (up to 10,000 m²/g) have led to many applications in gas storage and separations for clean energy. This presentation will focus on (1) how one can design porosity within MOFs to affect highly selective separations (carbon dioxide), storage (hydrogen and methane) and catalysis, and (2) a new concept involving the design of heterogeneity within crystalline MOFs to yield sequences that code for specific separations and chemical transformations.

 

2:30 p.m.           Exploring the Interactions of Ions, Peptides, and Proteins with Lipid Membranes

Professor Paul Cremer   Pennsylvania State University

Biological membranes often contain negatively charged lipids such as phosphatidylserine, phosphatidylglycerol, phosphatidic acid, and gangliosides. The groups of these lipids can strongly interact with positively charged aminoacids from peptides and (i.e. Arg and Lys residues), metal cation from the extracellular solution as well as positively charged drug molecules. These negatively charged lipids are highly regulated within cells and are highly abundant in certain organelles while almost completely absent in others. Moreover, their concentration within a particular leaflet of a given membrane is often tightly regulated. Despite the high degree of control of lipid composition within cells, little is often known about the reason for it or even the specific nature of ligand-receptor binding interaction with such moieties. To remedy this, we have employed a combination of spectroscopic techniques, microfluidic platforms, monolayer and planar supported bilayer architectures to explore the specific biophysical chemistries of these interactions. This includes the development of a novel analytical tool that employs a pH sensitive fluorophore to probe subtle changes in the surface potential of lipid bilayers upon ligand or ion binding. Both thermodynamic and molecular level details of these systems have been obtained. The results reveal that binding can be highly dependent on the concentration of specific lipids within the membrane. Moreover, the presence or absence of various uncharged lipids can also greatly influence the binding properties. Interestingly, specific interactions involving hydrogen bonding, charge transfer, and hydrophobic interactions often dominate over simple electrostatic effects.

 

3:15 p.m.           Coffee Break

3:45 p.m.           The Surface Chemical Bond: Explorations of Structure and Dynamics

Professor Steven L. Bernasek   Princeton University

The tools of molecular surface science developed over the past fifty years have enabled the examination of the nature of the surface chemical bond and its dynamic behavior in unprecedented molecular detail. In my lecture I will discuss two examples of this sort of work. I will comment on the insights that have been gained in the basic understanding of surface chemical processes using this approach, which has been pioneered by this year's recipient of the Nichols Award. This understanding provides important foundations for the range of applications described in this symposium.
The first example focuses on the process of molecular self-assembly at well-characterized surfaces. The use of molecular beam scattering as well as scanning probe microscopy, coupled with electron spectroscopic and microscopic methods, provides information about the formation and energetics of chiral and achiral organic monolayers and designed nanostructured surfaces. Implications for the understanding of homochirality in biological systems, and applications in organic electronic device design will be mentioned.
The second example uses the tools of surface science, coupled with optical pulse shaping methods, to address the quantum control of surface chemical dynamics. Carefully designed self-assembled monolayer samples along with surface sum frequency generation as a feedback signal, have been used to optimize selective bond manipulation at the surface. Possible applications to heterogeneous catalysis and electronic device preparation will be presented.

 

4:30 p.m.           The Genesis and Integration of heterogeneous, Homogeneous, and Enzyme Catalysis on the Nanoscale

Professor Gabor A. Somorjai,   University of California - Berkeley

Nichols Medalist

The synthesis of metal and bimetallic nanoparticles in the 1-10 nm range, and mesoporous high surface area oxides, were utilized as heterogeneous catalysts. The rates and chemical selectivity of multipath reactions were dependent on the nanoparticle size and the oxide-metal nanoparticle interface composition. Instruments including laser spectroscopy (sum frequency generation vibrational spectroscopy) and synchrotron based x-ray spectroscopies and scanning tunneling microscopy reveal the mobility and dynamic restructuring of adsorbed and reacting molecules and catalyst surfaces under reaction conditions. The formation of covalent bonds between the adsorbed molecules and the diverse structures of the catalyst surfaces are one important ingredient of catalytic selectivity. The charge transfer of oxide-metal interfaces to the reacting molecules (acid-base catalysis) is the other important property of catalytic reactivity. Metal nanoparticles at 1 nm size (40 atoms) and below behave as single metal-ion transition metal homogeneous catalysts. Studies of adsorbing enzyme catalysts on oxide surfaces explore how their rates and chemical selectivities are altered in progress.

 

5:45 p.m.           Social Hour

6:45 p.m.           William H. Nichols Medal Award Dinner
                Professor Kenneth Eisenthal of Columbia University
                will introduce the 2015 Medalist