The Meyer Lab has a wide range of research interests based in transition metal chemistry. We have multiple ongoing collaborations with professors in both biological to physical chemistry. Members of the Meyer lab are closely involved with other groups in the Chemistry department, including Lin, Papanikolas, Templeton, Thorp, and You.
The unifying theme of our many projects is energy conversion. By studying the basic principles of electron transfer, excited states, and redox catalysis, we hope to advance the frontier of knowledge in renewable energy research. For example, we are currently investigating mechanisms of proton-coupled electron transfer, in order to understand how water is oxidized by Photosystem II during photosynthesis.
Students and researchers in the Pielak Group, use the formalisms of equilibrium thermodynamics and the tools of molecular biology and biophysics to understand protein structure, stability, and function.
Currently, our research focuses on In-cell NMR, a new method which allows us to obtain high resolution NMR data from proteins in living cells. Much of this work involves quantifying the effects of macromolecular crowding on protein chemistry. Additionally, we study the oxidative aggregation of the key protein involved in Parkinson's disease,
α-synuclein.
As published in JACS, researchers in the Murray Group show how oxidation of dissolved 1.6 ± 0.6 nm (dia.) IrIVOx nanoparticles in pH 13 solutions leads to a 100% current efficient oxidation of water to O2, at a modest overpotential η of only 0.29 V, relative to thermodynamic expectations for the four electron H2O→O2 reaction.
Each nanoparticle contains an average of 66 Ir sites; all are electroactive, so that the nanoparticles act, effectively, as 66 electron transfer mediators in the water oxidation. Each Ir site has a turnover frequency (TO, mol O2/Ir sites/s) of 8−11 s−1, which is nearly the same as observed for films of IrIVOx nanoparticle composed of similar nanoparticles, and providing the first comparison of electrocatalysis by nanoparticle films with redox catalysis by dissolved, diffusing nanoparticles.
Carolina Chemist and John P. Barker Distinguished Professor Michael Rubinstein, has been awarded the 2010 Polymer Physics Prize from the American Physical Society. The prize recognizes outstanding contributions in polymer physics research, specifically professor Rubinstein's leadership in the field of structure and dynamics of polymer liquids, interfaces and gels.
Most of the materials around us, from plastics to tires, and inside us, DNA and proteins, are made of polymers - giant, chain-like molecules. The goal of Rubinstein’s research group is to understand how polymers move through a tangle formed by their molecule neighbors and how they are deformed if attached to each other in a network, then pulled apart, like stretching a rubber band. UNC researchers are modeling polymers in the lungs with the goal of developing treatments for diseases such as cystic fibrosis.
The unique properties of polymers that make them the materials of choice in many industries are their enormous size in comparison to ordinary molecules and their ability to change under the influence of surrounding molecules, according to Rubinstein.
Rubinstein received his bachelor’s degree from the California Institute of Technology and his master’s and doctorate degrees from Harvard University. He will be presented the award at a meeting of the American Physical Society in March 2010.
To generate model substrates for cell adhesion, the Yousaf Group has developed two different biocompatible strategies based on self-assembled monolayers (SAMs) of alkanethiolates on gold terminated with latent ketones and aldehydes. Under spatial control, the hydroquinone and alcohol terminated SAMs can be oxidized to allow for oxyamine ligand patterning on the surface with microfluidic cassettes. These immobilization strategies were characterized by electrochemistry and fluorescence microscopy. By utilizing a cell adhesive peptide, cell patterns were also generated.
These methods are of broad utility to the research community as an easily accessible chemoselective strategy to immobilize ligands to surfaces. Previous immobilization strategies require multistep synthesis to generate the reactive head group on the surface. The Yousaf method requires either a simple synthesis or commercially available materials. The many different functional groups compatible with carbonyl chemistry allow for a range of ligands to be immobilized. In the future, the ability to oxidize hydroxy terminated SAMs may be extended to tailor a broad range of materials for molecular electronic and biological sensing applications.
Joseph DeSimone, Chancellor's Eminent Professor of Chemistry at UNC, and William R. Kenan, Jr. Distinguished Professor of Chemical Engineering at NCSU, has been selected to receive this year's North Carolina Award in Science.
Considered one of the nation’s premier scientists, Joseph DeSimone was selected because of his cutting edge research with revolutionary results for cancer treatment, green chemistry and photovoltaics. His breakthroughs in nanotechnology applications and in the fields of polymer chemistry, pharmacology, and biomolecular engineering, have produced life-changing and world-saving inventions.
The North Carolina Award is the highest civilian award bestowed by the state of North Carolina, and is sometimes referred to as the "Nobel Prize of North Carolina." The awardees are chosen by the North Carolina Awards Committee, appointed by the governor of North Carolina and supervised by the state's Secretary of Cultural Resources.
Joseph DeSimone is the sixth Carolina chemist to be honored with this award. Previous Carolina recipients are Oscar Rice, 1966, Ernest Eliel, 1986, Robert Parr, 1999, Royce Murray, 2001, and Maurice Brookhart, 2008.
Protein tyrosine phosphatases (PTPs) regulate a broad range of cellular processes including proliferation, differentiation, migration, apoptosis, and immune responses. Dysfunction of PTP activity is associated with cancers, metabolic syndromes, and autoimmune disorders. Consequently, small molecule PTP inhibitors should serve not only as powerful tools to delineate the physiological roles of these enzymes in vivo but also as lead compounds for therapeutic development.
In a collaborative work published in JACS, the Lawrence Group describes a novel stepwise fluorophore-tagged combinatorial library synthesis and competitive fluorescence polarization screening approach that transforms a weak and general PTP inhibitor into an extremely potent and selective TC-PTP inhibitor with highly efficacious cellular activity. The result serves as a proof-of-concept in PTP inhibitor development, as it demonstrates the feasibility of acquiring potent, yet highly selective, cell permeable PTP inhibitory agents. Given the general nature of the approach, this strategy should be applicable to other PTP targets.
The Baer Group has published a threshold photoelectron photoion coincidence study in which the energy required to dissociatively ionize propene (C3H6 + hv → C3H5+ + H + e-) was measured to be 11.898 ± 0.024 eV. When this is combined with a recently reported ionization energy of the allyl radical, see Figure below, a high precision propene C-H bond energy (BE) as well as the proton affinity (PA) of allene could be established.
This study was complicated by the slow dissociation of the propene ion, which caused previous investigations to be too high, thereby underestimating the PA and overestimating the BE. The Baer group established the correct dissociation onset by measuring the dissociation rate constants as a function of the ion energy by time of flight mass spectrometry, and extrapolating the rate to the dissociation onset.