Viewing archived talks in: St Andrews
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St Andrews
A Marriage of Supramolecular Chemistry with Chemometrics
Speaker: Prof Eric Anslyn (University of Texas at Austin)
A Marriage of Supramolecular Chemistry wi th ChemometricOn: February 19, 2019 From: 16h30 To: 17h00
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St Andrews
Probing and harnessing the hydrophobic and Hofmeister Effects
Speaker: Prof Bruce Gibb (Tulane University)
Probing and harnessing the hydrophobic and Hofmeister Effect s A better understanding of how molecules interact in aqueous solutions has ramifications a cross the biosph ere, lithosphere, atmosphere, and hydrosphere . For example, aqueous solutions of dissolved organic molecul es and salts are central to all of biolo gy and biochemistry . Un surprisingly, documented studies of h ow organic solutes, dissolved sa lts, and water interact with each othe r arguably go back to at least the late 18 th Centur y with Franz Hoffmeister ’s seminal work on protein solubility . However, to date no comprehensive atomistic model of the interactions between this trinity of solute, s alt, and water has been forthcoming. For some time now , our research has focused on building up an atomistic view point of aqueous supramolecular chemistry. In doing so we envis age not only being able to subtly engineer and contro l specific molecular inte ractions at the atomistic level to engender un usu al phenomena , but also apply this information to build ing a better understanding of bulk phenomena such as solubility . This presentation will focus on o ur recent stu dies into aqueous supramolecular interact ions uti liz ing deep -cavity cavitands as models . We will discuss how these interactions control the bulk prop erties of the hosts, and how they can b e harnessed to yield novel supramolecular containers that function as yoctoliter reaction vess els and tools for bringing about separation protocols. 1 References 1. (a) Jordan, J. H.; Gibb, C. L. D.; Wishard, A.; Pham, T.; Gibb, B. C., J. Am. Chem. Soc. 2018, 140 (11), 4092 -4099; (b) Hill yer, M. B.; Ga n, H.; Gibb, B. C., ChemPhysC hem 2018, 19 (18), 2285 -2289; (c) Sokkalingam, P.; Shraberg, J.; Rick, S. W.; Gibb, B. C., J. Am. Chem. Soc. 2016, 138 (1), 48 -51; (d) Wa ng, K.; Gibb, B. C., J. Org. ChOn: February 19, 2019 From: 16h00 To: 16h30
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St Andrews
Structural (dis)order as a pathway to functional materials
Speaker: Sian Dutton (Cambridge)
Structural (dis)order as a pathway to functional materialsOn: February 20, 2019 From: 14h00 To: 15h00
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St Andrews
Cu(I)-Based Complexes for Photocatalysis
Speaker: Shawn Collins (University of Montreal)
The development of heteroleptic Cu(I) -based complexes for photocatalysis will be presented. Initial discovery, reaction optimization and transfer to flow chemistry wil l also be discussed. In addition, alternative photochemical syntheses using UV -light, Fe(II) -based complexes and combinatorial screening approaches to reaction optimization will be highlighted.On: February 25, 2019 From: 16h00 To: 17h00
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St Andrews
On discovery in catalysis (Merck, Sharp & Dohme Award Lecture)
Speaker: Frank Glorius (Muenster)
TBCOn: February 27, 2019 From: 14h00 To: 15h00
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St Andrews
Tailoring the Photophysics of First-row Transition Metal-based Chromophores for Light Capture and Conversion: Challenges and Opportunities
Speaker: Jim McCusker (Michigan State)
https://talks.st-andrews.ac.uk/index.php?talks/talk_details/990
Figure 1. P lot of the ground state recovery dynamics of [Fe(bpy) 3 ](PF 6 ) 2 in CH 3 CN solution as a function of temperature following 1 A 1 ® 1 MLCT excitation . The solid line corresponds to a fit of the data to an Arrhenius mod el, indicating an activation energy of 310 ± 15 cm -1 and an intercept (i.e., the rate constant in the limit of no barrier) of 230 ± 20 ps -1 . An analysis of these data in the context of semiclassical non - radiative decay theory is providing new insights into the factors controlling ultrafast dynamics in such systems. Tailoring the Photophysics of First - row Transition Metal - based Chromophores for Light Capture and Conversion: Challenges and Opportunities James K. McCusker Department of Chemistry, Michigan State University The conversion of light to chemical energy is one of the most fundamental processes on Earth. It is the basis of photosynthesis, in which light absorption results in the separation of charge that ultimately creates the chemical potential needed to drive ATP synthesis; an advantageous by - product of th is process is, of course, O 2 production. Ironically, photosynthesis is also the source of the biomass from which the fossil fuels that constitute the basis of society’s energy infrastructure are derived. The overwhelming majority of climate scientists are in agreement that it is the burning of these fossil fuels – in effect the re - release of what was sequestered carbon into the atmosphere – that is driving global climate change. Options for shifting away from fossil fuels as our primary energy source genera lly revolve around renewables such as wind, solar, biomass, nuclear, geothermal, and hydro: of these, the only renewable energy source that is limitless and carbon - free (at least in principle) is solar. The energy flux hitting the Earth is 120,000 TW: inte grated over a 24 - hour period, this translates to humankind’s total energy budget for an entire year. Despite the progress that has been made in the implementation of solar energy (due primarily to reductions in the cost of silicon), the intermittent nature of solar energy, the balance of systems costs that continue to represent a significant economic obstacle, combined with the fact that electricity constitutes only ~30% of the global energy footprint all underscore the need for continued research in solar energy conversion science. Fundamental research on solar energy conversion – which will ultimately lead to the next generation of solar energy technologies – has sought to replicate Nature’s solution through the creation of artificial constructs that mimic va rious aspect of photosynthesis. When considering large - scale (i.e., global) implementation of any solar energy conversion scheme, material availability becomes a critically important consideration in the light - capture part of the problem, particularly w hen one considers the projected two - to three - fold increase in energy de mand over the next 30 - 40 years. Unfortunately, virtually all of the molecule - based approaches for solar energy conversion that have been proven successful rely on some of the least abu ndant elements on earth. An obvious alternative is to employ chromophores based on earth - abundant materials: for transition metal - based approaches, this means moving away from the second - and third - row transition series elements (e.g., ruthenium) and devel op photoredox - active chromophores based on first - row, widely available metals like iron and copper. As our group first demonstrated in 2000, the central problem with this approach is that the charge - transfer excited states that lie at the heart of photo - in duced electron transfer chemistry exhibit sub - picosecond lifetimes (as compared to the microsecond lifetimes of their 2 nd - and 3 rd - row congeners). Our research program therefore focuses on understanding the factors that determine the dynamics associated wi th the excited states of first - row transition metal - based chromophores, with the ultimate goal of circumventing and/or redefining their intrinsic photophysical properties in order to make feasible their use as light - harvesting components in solar energy co nversion schemes . This seminar will describe the key experimental results establishing this paradigm, as well as survey several approaches that we are pursuing in an effort to broaden the utility of this class of chromophores for a wide range of solar ener gy and chemical transformations
On: March 4, 2019 From: 13h00 To: 14h00
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